6.2 suddenly smoking bad after cold start ,and misfiring..

[diesel4me]

The 6.2 in my 82 K2500 has started belching a cloud of white smoke bad ,after a cold start,which lasts several minutes until it warms up--also,unless I hold the gas pedal at a faster idle,the engine wants to stumble and stall,and it sounds like it has a few cylinders that aren't firing consistently,the engine sounds kind of like an over choked gas engine-"lopey"-- after it has run a minute or so,long enough that I can let off the gas and not have it stall, it does the misfire/ over rich lope until it warms up good..once its fully warmed up it runs normally..

I know all diesels belch some smoke after a cold start,but it has never done it like this before,nor did it have the other symptoms listed above..

I checked the coolant level,its ok,and the radiator didn't have any excess pressure in it,so I don't think its a head gasket leaking..oil looks black as usual,no mayonaise on the dipstick..

Some other things I noticed today after I put the plow on it (its going to snow here overnight ),I went for a ride to get some gas for my tractor and when I had to accelerate up a long grade,it downshifted into passing gear,took off OK,but then felt gutless,and then bogged down like it was going to die on me..
I let off the throttle and it recovered,but still felt like it was lacking fuel..luckily it did not stall..

When I got to where I was headed,I turned off the engine and then turned the key back "on"--and I listened,I did not hear the electric fuel pump come on..
Usually you'll hear that woodpecker ticking sound..

I know it does not always run,if there is pressure in the fuel lines,it will stop on its own,and only pulse when it needs more fuel..but now I'm wondering if its just that,or if it croaked ..it has been on the truck since I got it in late '03..
I could open the fuel filter drain and see if the pump came on,but I didn't want to get diesel on me--my house already reeks of it thanks to some spilling on my shoes and pants the other day..

This pump is mounted close to the fuel tank and the stock lift pump on the engine is still hooked up also,so its like an assist pump---so if the electric pump died,it may be running off the lift pump alone, and it cant suck enough fuel thru the electric pump with it not on..

I'm thinking it may have a few dead glow plugs--it is the drivers side that smokes the most,hardly any comes out of the other bank..(and that side I know has a dead glow plug I cant get out,been that way since day one)..truck fires right up OK,you don't have to spin it over much--but I haven't tested the glow plugs yet..
Question is,would a dead glow plug make it smoke that bad after a cold start?
It would have to be putting a lot of unburnt fuel into the exhaust manifold I'd assume..

Another issue too--the other day when I filled the tank up,the pump at the gas station was pumping very slowly--it took over 5 minutes to get $20 worth of fuel,and then the nozzle failed to click off and diesel spewed all over my shoes,pants,and the ground..
I'm wondering if that pump had a clogged filter--or worse,the fuel had water in it..

I replaced the fuel filter about 4000 miles ago,and hate to buy another one at $25+ bucks if that isn't the problem..no one has one in stock locally either right now..

I was tempted to try draining it when I got home awhile ago,but I figured it best not to touch it--I need the thing to plow with,and it will be under 15 degrees for a few days starting tomorrow afternoon,so I'm not going to be out there dicking with it and possibly end up disabling it worse..

Any suggestions what it might be ?..my "guess" is its either the electric pump might be dead,or the fuel is crap...maybe the filter is clogging up...?

I hope it'll run tomorrow and be able to plow--wont be able to work on it until the middle of the week,when it might hit 40 again --and rain,of course..

 

[K5wrench]

Bad glow plug(s)
If you simply remove the wire from the glow plugs, one at at time, test with ohm meter from tab on glow plug to ground.
Should be .8 to 1 ohm.
If any of them read infinite, they are dead.
I had a few dead ones when i got my 6.2 blazer.
It had the Military 24 v system but used a resistor bank to step voltage down to 12 volts under load.
What happened is one plug would die, the survivors suddenly get more voltage.
Cascade failure.
I can tell you even 2 bad glow plugs make it very hard to start below freezing.
4 plugs.. forget it.
They are damned expensive little things too.
I run AC Delco 60g's.
It's $80 for 8 of them.
But they won't swell up and be stuck.

I'd test them with the ohm meter.
I bet you finally lost more than one.
Your symptoms of rough idle and smoke at cold start but smooth and smoke free when warm.. that is glow plugs.

Edited to add pic of special glow plug socket.
This Snap On socket is incredible for glow plugs.
Highly recommend it.
The only Snap On thing I own.
Marked S6105A Snap On USA.
Yes, a 3/8" deep well. But with a retainer to hold the glow plug and just the right length to fit.

 

[KirsL]

A few bad glowplugs will make for a hard start and the smoke while warming up. The glowplugs get cycled for the first few minutes of run time. New ones aren't too expensive. Just put some anti-size on the new ones. Keeps them from getting stuck.

The other thing to check is the cold-idle advance switch. Does the engine go to fast idle when cold? If it doesn't the cold idle switch is probably bad. It screws in the same spot as the temperature sensor just on the passenger side of the engine.

If you have factory A/C it's kinda hard to get to but still doable.

 

[tRustyK5]

I think your electric pump shit the bed too...

 

[diesel4me]

The fast idle/cold start advance works OK and is on a toggle switch..the sensor in the head had the plastic guts come out long ago,and the wires caught on fire on the exhaust manifold,so I made it "manual",and the glow plugs are on a manual push button also..

I test the glow plugs by unplugging them,and applying a test light hooked to the positive battery terminal--if it lights up,its good..
I now have a digital multi-meter too though,maybe I'll try that method.

Problem is,I have ruined several good glow plugs ,when I go to unplug them,the spade busts off!..the connectors rust solid to the spades..(and I've put never seize or grease on them when I installed them too--a few had the hex rotted away to nubs too,I was lucky that they came out with a metric socket hammered onto them..)

I've had to replace several of the slip on connectors on the wires too,they were all rusty and corroded..some of the wires themselves were green at the connectors and only had a few strands left ,had to cut them shorter and install "regular" solderless connectors (all I had available at the time)..now some wires are barely long enough ..

I use AC 60G glow plugs normally--but I had a dozen or so 9G ones hanging around that were good,last time I replaced at least one on the drivers side,I used those instead--now I may regret that,they are the ones that can swell up,and maybe having a mis-matched array of them may allow one to glow hotter than the rest and burn up ..

I got tired of shelling out $10 a piece for the 60G's..
(Autozone now has them for just over $9 now though)..especially when I had to toss away ones that still worked,but had the spade come off..
I'm living on a tight fixed income and $10 is $10,I cant be throwing money away..I bet I've put 2 dozen glow plugs in this thing since I've owned it,with less than 10,000 miles in 16 years..most failed due to the spade coming off too..

The fuel starvation symptom is much more disturbing to me,I hate the feeling your going to have to call for a tow,especially in this weather,and I don't have AAA..and if it ends up being the electric fuel pump,another one of those will be like $50 locally--I'd get one online if I had the means,but I lack credit cards,and it is a pain to have to go get a pre-paid one..

I'm so "done" with diesels..though this one owes me nothing,and hasn't been that bad,I don't "need" a diesel,and I'd rather have a good old straight six instead,or a small block than this lump any day...

Every year the list of woes it needs fixed grows,and I'm less able to do them..its had a rotted oil pan that leaks a long time,I have two I could use on it,but cant lay under it long enough to do it,so I patched the original with fiberglass and silicone RTV--if it ever needs a lift pump or water pump,I'd rather yank the engine out to replace them--then probably not fix it,or put it back in..I'd put one of the small blocks I have back in it instead..then the TH400 will shift better too,the hokey vacuum pump arrangement sucks..

Gas engines start easy in any temperature,use less costly fuel,and no $500 injector pump to muck up,injectors,and the starters last longer (put 3 in this truck in 10,000 miles)....only thing I'd miss is the fuel injection if I go back to a carbed engine,but I don't mind letting an engine warm up..or having to do "tune ups"..they are so much easier to work on,at least for me..my back & legs are dead now,I may not even be able to do an oil change now,never mind anything more involved..

 

[tRustyK5]

A small block will drop right in there...

 

[diesel4me]

I think your electric pump shit the bed too...

That is possible,but as I said,I will have to open the filter drain and turn it on and see if it'll pump then..it may be it was pumped up to full pressure when I went to listen to it..
I'll have to make sure its getting power too..

It is one of those round fuel filter looking pumps,I think it has a solenoid and nylon ball inside for the pump,not a bellows..could be ice in it ,if the fuel has water in it too...

Think it's time for me to go to bed..had enough discouragement for one day..

 

[diesel4me]

A small block will drop right in there...

Yeah I know..should have dropped one in it 15 years ago!...when I had a sweet running 400 SB from my previous plow truck,which I stupidly sold for $150 when I was hard up for cash..

I have two 307's I picked up last summer off craigslist,but have not yet tried firing either one up ..
One is from a '70 K-10,the other was from a '71 Chevelle..the Chevelle one supposedly ran nice,the guy swapped a 454 in the car and stashed the 307 away,he taped up everything so no mice or dirt could get in it,sat in his shop a long time..he was going to put it in a '61 Biscayne his neighbor has,with a seized 283,but he decided to get out of doing "projects"..
The truck engine has decent compression (125 psi in all 8),but I have not attempted to start it yet--it has a short tail TH350 coupled to it,I bought both for $75 ,that was all I was willing to give in case they turn out to be scrap..the guy working on the truck had no clue if it ran or was good,it was half out of the truck when he bought it--it turns by hand OK and I bet there isn't much wrong with it..
The TH350 has a chunk taken out of the bell housing ,at the bolt above the dowel pin on the starter side..I think it'd live with 5 out of 6 bolts,I've run 4 out of 6 before when I put one from a Buick in a '67 Impala I had,never had a problem..

I bet the 200 HP 307 would feel like a 454 compared to the 6.2's 140 HP..the torque on a 307 is 300 ft/lbs too,more than the 240 the diesel makes,but you have to wind up the 307 a lot higher to hit the peak..

 

[tRustyK5]

I'd swap one of those in, in a New York minute...

I'd actually probably wait for the winter BS to go away, then do it and get it over with. It'd be nice to have a reliable, easy to start truck again, wouldn't it?

 

[red EOD]

Those little round fuel pumps lack the ability to flow enough volume for even a 6.2 at wide open throttle. Walbro FRB 5 or FRC 10 are some of the cheapest reliable electric diesel fuel pumps that move enough volume.

Mixing glow plug models doesn't work for too long. The 9's are a "quick" heat and not self limiting (constantly get hotter the longer it's energized till it burns out), 60's are a "slow" heat and are self limiting.

 

[diesel4me]

^ This is what's been on it for 16 years,the engine seems happy with the volume and pressure it makes,plus it is in tandem with the stock mechanical lift pump on the engine...though I have never driven it at 70 mph long distances,it accelerates up to highway speed fine and maintains the speed limit up hills with the two pumps..

I have the pump hooked up to a toggle switch--I've tried driving it with it shut off,and it does seem to run OK on just the lift pump--but if you stuff it to the floor up a hill ,you'll feel it start to starve for fuel..
So the lift pump can suck fuel thru the electric one,even it it shut off,but it does restrict the flow a lot evidently..

The pump was mounted under the cab but not connected to anything when I bought the truck..someone had butchered everything for the dual tanks it had--they removed the selector switch on the dash,and the valve that switches tanks under the truck,made a mess of the wiring.and tried adding a manual shut off valve under the truck to swap tanks..

I just removed one leaking tank on the right side and plumbed everything up to the drivers side tank,and hooked up that electric pump when I tried it and it seemed to run OK..why it was just mounted but never connected (or was,and "deleted ?),is a mystery,its always worked good ..

I get by with one tank fine,I can go 300 miles on a full tank,and I rarely go far--especially in this war wagon,the buckboard ride and cramped seating makes it a poor choice for a long trip..

It was against my better judgement to use those 9G's ,but not having a lot of cash to blow on 60G's I used what I had...just hope they'll come out OK and aren't "exploded"..

The weather here sucks today--what was supposed to be 6" of snow,ended up turning to heavy rain about 3 am,after we got about a whole 1-1/2",now that is pure slush,it is about 40 degrees now--it is expected to climb to perhaps 45-50 by noon,then it will plummet to 5 degrees by Monday morning,so everything is going to freeze solid--supposed to stay frigid Tuesday,then warm up to 40 again with more rain again..

A few minutes ago there was a very loud rumble of thunder!....pretty rare to hear that in January..it is pouring out right now,so there wont be any troubleshooting or repairs being done today..

I have to get my butt out there and scrape that slush off the driveway and steps,and front walk,before it turns into a glacier..would rather have had the 6" of snow than this ....

Hope the truck will run OK long enough to plow the driveway--I don't feel like sitting on a garden tractor in a 40 degree monsoon to plow the driveway..

Yes Rene,it would be nice to have a truck that starts right up again,especially in winter--without spending a lot of cash & labor on glow plugs,starters,two batteries,having to plug in the block heater (more $$),and still maybe not get it to start if its really frigid ..
Having fuel cost 50 cents a gallon less is a plus too..and I bet the mpg will be the same too,maybe slightly better..

The only big "IF" is whether I will be able to tackle an engine swap--right now I'd be lucky to be able to swap an engine on my garden tractor..and IF the truck is really worth all that effort--its nose is pretty trashed,inner fenders rotted to nothing,fenders are roached,so taking the nose off and replacing "everything" would make an engine swap easier..

But I still don't know yet if either of those 307's are any good either..they may turn out to be scrap iron--I am going to attempt to get them started on a makeshift "test stand"..

I also need to find some pulleys for them,I only have the crank pulley on one engine,and the water pump one on the other,and no brackets for the alternator--I may have those buried in my parts pile off other trucks I had though..if I dont I'll have to scrounge some up at a swap meet or boneyard..not buying anything for the 307's till I hear them run,they may end up needing a camshaft & lifters,90% of them had flat lobes in that era if they have the original cam..

I may end up selling the diesel Suburban,plow & all,I dont see me being able to fix it up now or put it on the road..
I'm going to keep looking for another square body --I might luck out and find one better than mine for under $1500..that would be much easier than an engine swap and fixing all the other issues on the pickup or Suburban..

 

[red EOD]

View attachment 292243
^ This is what's been on it for 16 years,the engine seems happy with the volume and pressure it makes,plus it is in tandem with the stock mechanical lift pump on the engine...though I have never driven it at 70 mph long distances,it accelerates up to highway speed fine and maintains the speed limit up hills with the two pumps..

I have the pump hooked up to a toggle switch--I've tried driving it with it shut off,and it does seem to run OK on just the lift pump--but if you stuff it to the floor up a hill ,you'll feel it start to starve for fuel..
So the lift pump can suck fuel thru the electric one,even it it shut off,but it does restrict the flow a lot evidently..

That's normal characteristics with those cheap electric pumps. Adequate for empty driving around town and make it easy to prime the fuel system after a filter change is really all they are capable of. If you were to install a pressure/vacuum gauge between the mechanical and electric lift pumps then drive around you would see the gauge go from a pressure of about 5psi (at idle), drop down to a vacuum under heavier loads. Any vacuum in the fuel line AFTER a lift pump means that it is inadequate, which forces the injection pump to work harder by drawing fuel through the lift pump. To reference it like a carb (since most here are gas fans), these little electric pumps when working are the equivalent of installing a 300cfm carb onto a 454 big block.

With the electric pump not working, those pumps fail and become a restriction. They lock up which blocks most of the fuel flow path through them. Better pumps fail but still allow the internals to move which doesn't restrict fuel flow as much.

Cheaper source of 60G glow plugs https://www.amazon.com/gp/product/B000C9N54C/ref=ox_sc_act_title_1?smid=A2BEWZZG8ARGEZ&psc=1

For the block heater, it only needs to be plugged in for 2-3 hours before starting the truck (with glow plugs not working).

 

[diesel4me]

Block heater I have on it is the heater hose type--it "works" but I think its only 400 watts,so I have to leave it on at least 4 hours if its below 20F,even then its a gamble whether it would start..

I bought another identical one brand new for $3 at the flea market,to have for a spare,if that one croaks..there was a freeze plug heater in the block,but the cord was cut off..I didn't want to risk making it leak,so I refrained from messing with it--might not work anyways..

Since I put newer batteries in the truck it does whip over nice now--the ones that were in it when I bought it were old Duralasts,dated 1-2001,and 8-2002!..and one still passes a load test,the other dies instantly under load..pretty good life span considering they were only group 74's and not that "big"...

As for the electric fuel pump,if it ends up being junk,I may just by-pass it for now and run it off the lift pump in stock configuration..and pray I never have to replace it,I hate where they stuffed it--small block fuel pumps are bad enough to get at..
If I get another one I don't know if its worth buying the "better" one,seeing I got by with this one OK for so long..

I'm not in great shape and cant lean over or crawl under a truck like I used too any more,and few mechanics I know will even touch this truck,they hate diesels and rotted vehicles--cant say I blame them..couldn't afford what they would charge either if they were willing to put a lift pump on it,or do any of the other repairs..

 

[campfire]

The 6.2 in my 82 K2500 has started belching a cloud of white smoke bad ,after a cold start,which lasts several minutes until it warms up--also,unless I hold the gas pedal at a faster idle,the engine wants to stumble and stall,and it sounds like it has a few cylinders that aren't firing consistently,the engine sounds kind of like an over choked gas engine-"lopey"-- after it has run a minute or so,long enough that I can let off the gas and not have it stall, it does the misfire/ over rich lope until it warms up good..once its fully warmed up it runs normally..

I know all diesels belch some smoke after a cold start,but it has never done it like this before,nor did it have the other symptoms listed above..

I checked the coolant level,its ok,and the radiator didn't have any excess pressure in it,so I don't think its a head gasket leaking..oil looks black as usual,no mayonaise on the dipstick..

Some other things I noticed today after I put the plow on it (its going to snow here overnight ),I went for a ride to get some gas for my tractor and when I had to accelerate up a long grade,it downshifted into passing gear,took off OK,but then felt gutless,and then bogged down like it was going to die on me..
I let off the throttle and it recovered,but still felt like it was lacking fuel..luckily it did not stall..

When I got to where I was headed,I turned off the engine and then turned the key back "on"--and I listened,I did not hear the electric fuel pump come on..
Usually you'll hear that woodpecker ticking sound..

I know it does not always run,if there is pressure in the fuel lines,it will stop on its own,and only pulse when it needs more fuel..but now I'm wondering if its just that,or if it croaked ..it has been on the truck since I got it in late '03..
I could open the fuel filter drain and see if the pump came on,but I didn't want to get diesel on me--my house already reeks of it thanks to some spilling on my shoes and pants the other day..

This pump is mounted close to the fuel tank and the stock lift pump on the engine is still hooked up also,so its like an assist pump---so if the electric pump died,it may be running off the lift pump alone, and it cant suck enough fuel thru the electric pump with it not on..

I'm thinking it may have a few dead glow plugs--it is the drivers side that smokes the most,hardly any comes out of the other bank..(and that side I know has a dead glow plug I cant get out,been that way since day one)..truck fires right up OK,you don't have to spin it over much--but I haven't tested the glow plugs yet..
RQuestion is,would a dead glow plug make it smoke that bad after a cold start?
It would have to be putting a lot of unburnt fuel into the exhaust manifold I'd assume..

Another issue too--the other day when I filled the tank up,the pump at the gas station was pumping very slowly--it took over 5 minutes to get $20 worth of fuel,and then the nozzle failed to click off and diesel spewed all over my shoes,pants,and the ground..
I'm wondering if that pump had a clogged filter--or worse,the fuel had water in it..

I replaced the fuel filter about 4000 miles ago,and hate to buy another one at $25+ bucks if that isn't the problem..no one has one in stock locally either right now..

I was tempted to try draining it when I got home awhile ago,but I figured it best not to touch it--I need the thing to plow with,and it will be under 15 degrees for a few days starting tomorrow afternoon,so I'm not going to be out there dicking with it and possibly end up disabling it worse..

Any suggestions what it might be ?..my "guess" is its either the electric pump might be dead,or the fuel is crap...maybe the filter is clogging up...?

I hope it'll run tomorrow and be able to plow--wont be able to work on it until the middle of the week,when it might hit 40 again --and rain,of course..

Hard start could well be glow plugs. Running 9G and 60G plugs in parallel won't burn out the 60G plugs. But if you cycle them all long enough to heat up the 60G plugs the 9G plugs are probably toast. So they're not very compatible.

Remember that your truck came with two fuel filters. If you still have your secondary filter (bolted to the backside of the intake manifold), it may be that nobody bothered changing it in the last 37 years. It's easy to miss. Losing power at WOT sounds like lack of fuel, consistent with a plugged filter.

BUT...a dead lift pump can do the same thing, and if there is a tiny pinhole leak mixed in there, it will produce a lopey sound that only happens sporadically or under load. And it will be worst upon starting, if it's only using the mechanical pump. A failing IP can also do this, but will probably also have wandering timing, which you should be able to hear.

A fuel gauge would be invaluable in diagnosing the issue. Lacking that, I'd replace both filters and fix the lift pump. Most of these trucks have pin hole air leaks that aren't a problem until you aren't delivering enough fuel to keep the IP wet. Small amounts of air are able to burp back to the tank via the return line, but this won't help you if you aren't able to deliver enough fuel to keep the IP happy.

 

[campfire]

Bad glow plug(s)
If you simply remove the wire from the glow plugs, one at at time, test with ohm meter from tab on glow plug to ground.
Should be .8 to 1 ohm.
If any of them read infinite, they are dead.
I had a few dead ones when i got my 6.2 blazer.
It had the Military 24 v system but used a resistor bank to step voltage down to 12 volts under load.
What happened is one plug would die, the survivors suddenly get more voltage.
Cascade failure.
I can tell you even 2 bad glow plugs make it very hard to start below freezing.
4 plugs.. forget it.
They are damned expensive little things too.
I run AC Delco 60g's.
It's $80 for 8 of them.
But they won't swell up and be stuck.

I'd test them with the ohm meter.
I bet you finally lost more than one.
Your symptoms of rough idle and smoke at cold start but smooth and smoke free when warm.. that is glow plugs.

Edited to add pic of special glow plug socket.
This Snap On socket is incredible for glow plugs.
Highly recommend it.
The only Snap On thing I own.
Marked S6105A Snap On USA.
Yes, a 3/8" deep well. But with a retainer to hold the glow plug and just the right length to fit.

View attachment 292200

Civilian trucks do not have the resister bank like the CUCVs had, nor did they get the 13G plugs. They cannot have cascading failures in the same way that your truck (and mine) did. Though it's pretty easy to burn out a 9G plug with a manual switch, it's not going to kill off the 60G plugs it's paired with. 60G plugs have a slower response time and need longer power cycles to reach temperature. FWIW, I chucked my resistor bank and wired mine off the 12V bus like a civilian truck.

I haven't had a plug fall out of a socket yet, but I could see the desire to have the snap-on socket. Keep in mind that Bosch Duraterm plugs use a 10MM head instead of 3/8" head. I've used both, it's easy enough to mix them up and round off the 60G heads if you're mixing and matching.

 

[campfire]

Those little round fuel pumps lack the ability to flow enough volume for even a 6.2 at wide open throttle. Walbro FRB 5 or FRC 10 are some of the cheapest reliable electric diesel fuel pumps that move enough volume.

GM used "little round fuel pumps" for years with 6.2 and 6.5 trucks. I've never had an issue with the 3 I've used. But they were OEM or Delphi units spec'd out for that application. Not some generic knock-off pump.

 

[campfire]

As for the electric fuel pump,if it ends up being junk,I may just by-pass it for now and run it off the lift pump in stock configuration..and pray I never have to replace it,I hate where they stuffed it--small block fuel pumps are bad enough to get at..
If I get another one I don't know if its worth buying the "better" one,seeing I got by with this one OK for so long..

Running just the stock mechanical pump makes air bubbles a much larger headache. Replacing the electric pump is easier than trying to track down every little pinhole, IMO. Air is not the friend of this engine.

YMMV.

 

[red EOD]

GM used "little round fuel pumps" for years with 6.2 and 6.5 trucks. I've never had an issue with the 3 I've used. But they were OEM or Delphi units spec'd out for that application. Not some generic knock-off pump.

The in tank pumps? Yea different model than what's been discussed. Funny part is that even though those in tank pumps are much better than the little Carter round fuel pumps, still can't fully supply the injection pump at WOT under full load. Only drop down to about 2-5" of vacuum as compared to the generics dropping down past 15" of vacuum. Adequate enough for most users which is all the factory cares about.

 

[campfire]

The in tank pumps? Yea different model than what's been discussed. Funny part is that even though those in tank pumps are much better than the little Carter round fuel pumps, still can't fully supply the injection pump at WOT under full load. Only drop down to about 2-5" of vacuum as compared to the generics dropping down past 15" of vacuum. Adequate enough for most users which is all the factory cares about.

No, I'm using an ACDELCO EP158, stock for a 1988 C2500 with a 6.2. A little round can bolted to the frame

At WOT I have yet to see fuel pressure drop below +5psi at the filter assembly. It's true that I'm running stock fuel levels with a relatively gutless early-year 6.2. But it handles stock levels of fuel flow just fine.

 

[diesel4me]

My Suburban's 6.2 has only a electric pump I think,just like the one pictured above,and some moron mounted it right behind the rear leaf spring shackle on the passenger side,where it'll get blasted with salt and dirt..

I dont remember if that truck still has the lift pump hooked up or not--
I think its not hooked up at all,I'd have to look at it..
--whoever had it put a Racor filter on it on the firewall and also cut the rear floor out where the sending unit goes in the tank--supposedly it was set up to run bio-diesel but they never did..they also ran 15 feet of rubber fuel line all the way from the pump to the Racor filter!..

That might be why that 6.2 has to be cranked over so darn long before it'll fire up..that lone electric pump is too weak,especially with rubber line,probably just "inflates" the hose rather than allowing full pressure to get to the filter and engine..but once it starts and runs,they drove it around that way without starvation issues ,at least so claims the guy I bought it from..

My pickup's 6.2 starts almost immediately,even with a few dead glow plugs--it does not run right after it starts,it will run only at faster idle than the cold advance gives it,and the engine shakes and stumbles badly when the dead cylinders don't fire--after 30 seconds to a minute of holding it at fast idle,it'll then not stall,but lope like an over choked gas engine and misfire intermittently..once it warms up ,it smooths out and runs as good as it ever did..but without that electric pump running,it isn't getting enough fuel to pull a heavy load or pass someone without bogging down and wanting to stall..

I have not looked at the pump yet--right now its zero degrees here with a 20+ mph wind chill..I cant hear the pump pulsing with the key on,engine off,so I assume its either dead,not getting power,or it may have water that froze in it--or if the fuel filter is restricted,it may not "need" to pulse,because there is still pressure in the fuel line between the pump and filter..

I am 99% sure this engine has no secondary filter,someone ditched it before I got the truck--all I see is a rubber fuel hose going from the filter,directly to the injector pump..it could be that hose is so old it could be coming apart inside ,but I doubt it..

I have replaced the entire fuel feed line from the tank to the fuel filter with 3/8" copper,with only a few short rubber hose sections to connect it to the filter and pump--so I'm pretty sure there is no air getting in the fuel lines,and the fact it fires right up after only a few spins cold kind of proves that..

Yesterday completely SUCKED ..

We got pouring rain,on top of 2" of snow,we even had thunder around 9 am !..and the resulting slush after over 1" of rain fell was a mother to push off the driveway,my tires sank deep into the lawn,it was not frozen..

So I ended up using my garden tractor with a plow,which scrapes down to bare tar better that the truck's plow ,and wont rut the lawn all up--but the temperatures plummeted to below zero overnight,now everything left behind is frozen solid,and I did not do a great job of clearing the driveway--I had to ride the tractor in pouring rain,got soaked..

But not until I spent an hour getting THAT to start..
I had left the fuel shut off "on" last time I used it,and a whole tank of gas siphoned into the cylinder--had to put another spark plug in it and pull the rope 50 times before it finally chugged to life..
In the process my gloved hand slipped and now I feel like a finger is dislocated on my left hand,and the arm aches like hell..
I should have changed the oil before using it,probably had gas in it--but I was so pissed I just used it and didn't care if I blew it up..

Had more bad luck with the plow truck too..

The plow truck is now un-useable for plowing..

When I used it yesterday,there was a loud "BANG" coming from under the truck,sounded like the front hubs "slipping"..

I am hoping that is all it was,because I have slightly smaller front tires (245/75-16 vs 265/75-16 in the rear)...weird thing is last winter I ran two 255/70-16's up front with the same rears and it never "bound up" or made the "BANG" with those tires,and they were more "mismatched" than whats on it now..


I didn't feel any binding up while it was moving,but even at a crawl,something goes "BANG"--like maybe the transfer case,or the front hubs..

I had to replace both axle u-joints in the past--and the drivers side axle yokes were very thin,I'm praying that is not what failed and is getting caught on the axle tube's "C"...

If it is that--I may as well junk the truck,I'm not in any condition to go thru that job again..

Right now I feel like I belong in the hospital,I ache so bad all over and my heart keeps pounding like I ran a marathon ,when I do the least little effort..spent 15 yours in bed yesterday with a heating pad ..feel like I've been beaten with a bat all over..

I really do not feel well enough to do anything to the truck now,even if it was 50 degrees and sunny out....