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Having issues getting my diesel to run UPDATED 7-16-06

cegusman

3/4 ton status
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Houston/Katy, Tx
Motor has sat for 3 years, ran fine when pulled. Was locked up 3 days ago, finally got it to turn and running yesterday. Ran and idled for maybe 15 min, then went and did a few laps around my storage unit parking lot and a few donuts. After the donuts it died and would not start again, ran great for the time being. Ran maybe a totale of 25 mins. Today I added 5 more gallons to the tank to make sure I had fuel, reprimed it, got it to start by flooring it and cranking about 15 secs. Will run for about 5 sec then die. Then nothing again, have to reprime and it does the same thing 5 secs then dead.

Questions:

Air getting in the system somewhere?
I know my return lines are leaking at the injectors, could that cause a problem? Ordered new return lines today.
Plan on changing the fuel pump and replace all rubber lines this weekend. Could the injectors or injector pump be fubar from sitting so long?
 
To me I'd definitely be checking every possible place where you could be drawing in some air. When my IP and injectors needed rebuilding it just smoked like a train and several injectors started to leak...so I don't *think* it'd be either of those. Dripping return lines shouldn't cause it to airlock, although a sticky solenoid inside the IP could cause it to stall or hard/no start.

Rene
 
Did you flush out the fuel system before starting? 3 years is along time for diesel to be sitting.

When did you put in new filters? If there was crap in the tank they could be plugged up or very constricted already.

Pop the cover off your IP. Look for crud in the bowl.

Bleed your fuel lines again for air.

Check the fuel pump & lift pump.

Keep posting!
 
Tank was emptied and flushed when I took it out 3 years ago. Only new fuel is in it.

Old fuel filters where left on until I had fuel going to the injector pump, wanted them to catch any garbage. Then installed new filters.

Haven't looked in the injector pump yet.

Fuel pump was replaced Sat, found hose clamp on rubber feed hose going to fuel pump was lose and leaking. Should be my problem. Couldn't turn it over due to batteries being dead. Going to replace the starter today with a gear redution starter and charge the batteries over night.
 
Hope you found it. Sure is a pain in the arse when tracing things down and something else get in the way like dead batteries, stripped bolts. With me I usually break something while fixing something else:doah:
 
Got it running again yesterday. Ran great for over 2 hours, shut it down and it started right back up. 2-3 hours later went to start it, it started but took some cranking. Went to start it this morning and nothing, not any smoke out of the ehaust. Still a air leak? Could the fuel cap cause any problems? Also on the fuel sender on the tank there is a port for the water drain petcock valve, I have it plugged but it leaks. Would that cause any issues?
 
Got me stumped, but that's not hard:rolleyes::o

Check your fuel pressure? As a long shot check your glow plugs, when mine went bad they exacerbated other problems.
 
hmmm...

One way to see if air is getting into the system is to splice in a peice of clear Tygon tubing in place of the regular fuel line,and watch for bubbles...

I had one on my VW Jetta diesel...funny thing was,that car always started fine,but always had bubbles in the fuel line too!...never figured that out,but since it ran ok,I didn't care....:rolleyes:

You might have a leaky injector pump throttle shaft seal thats letting air seep in after several hours of sitting..usually they leak though,if they are letting air in...not sure about the nipple on the sending unit for water drain,they are usually blocked by a shut off valve anyway--as long as its sealed good it shouldn't be letting air in the system there...:crazy:
 
If you have the mechanical fuel pump it may have a bad diaphram. Earlier models had a problem with fuel being able to drain back after shut down causing a hard start.

Rene
 
other trouble spots....

Older diesel GM's had air leakage woes due to the fuel filter base being a bit warped ,and it didn't allow an airtight seal..the petcocks on the filter base and filter itself are prone to leakage also..I doubt your 2 day old fuel pump is to blame,unless perhaps it was bought at Auto-Zone!..(I've seen several poor quality parts purchased there lately..)

I read about some 6.2 injector pumps having a check ball in a fitting to prevent fuel drainback.(?)..I've never seen one myself,never had to mess with mine,and am not really familiar with the injector pump..other troubles like hard starts when hot can be injector pump related too,from what I've read....maybe try another fuel shutoff solenoid??..

I'm rather certain my truck would probably have the same starting troubles as yours does ,had I not installed the additional universal electric fuel pump as a "booster" to aid in priming the system,and boost the fuel pressure from the lift pump a bit..my truck sits for weeks to months without being started,yet it fires right up..I see drips of diesel on the driveway,so I'm sure my injection pump weeps a bit somewhere..:doah: ...

My GM service manual explains how to use a vacuum gauge to check the fuel lines for air leaks,and also to check the fuel pump..sounds like there is a pinhole leak in your fuel line somewhere that is letting air seep in,but not big enough to cause a drip to form...just like in brake lines,a little air can cause BIG problems..:crazy:
 
Filters are brand new Wix brand. I'm going to go ahead and change the rubber lines. Never messed with them since I changes the fuel pump and found the lose hose. Whats the chance of posting how to check for leaks with a vacuum gauge?
 
Lemme scan a few things for ya. They'll be in my 6.2 tech post...
 
Finally found my air leak, was the final rubber hose going into the injector pump that was dry rotted. Ran great and started fine everytime after I replaced it. Then I ran the motherf*cker out of diesel :doah:. Can't get it started now be cause 2nd starter is already dead:frown1:. Will try again tomarrow with a new starter.
 
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