Diesel blazer stops running at random

[JohnnyC]

Hey everyone. Let me preface this by saying my knowledge of diesels is rather... scarce...

Yesterday my 1985 cucv blazer did something rather strange. It was right in the middle of the day, after i had already driven it a couple times that morning without issue. I stopped at my buddy's, and when it was time to leave i started it up and backed out of the driveway, no problem. Put it in drive, made it about halfway down the block, and it just sortof petered out and shut off. I started it up again, made it to the stopsign at the end of the block, and it shut off again. So i started it up one more time, turned my corner and drove down the street to a parking lot. The whole way it kept feeling like it wanted to die; i basically had to put my foot to the floor to go 25-30mph. After i had driven about two blocks to the parking lot, i pulled in, put it in park, feathered the gas pedal a couple times, then just sat there a couple minutes and let it run. After that i drove a couple more times that day without experiencing the problem again.

Today around mid-day, again after i had already run and driven it a couple times this morning with no troubles, it happened one more time. started it up, put my foot to the floor for a bit driving down a side street, and after not even a minute it was back to normal and it ran fine the rest of today.

I have NO idea what this could be. Has anybody experienced anything like this and if so do you have any useful info for me? i appreciate any help. Thanks!

 

[Russell]

Did you notice any blue smoke behind you when it was running crappy? Sounds to me like it is running short on fuel. You may have a plugged fuel filter (either on the firewall or the pickup sock in the tank), or a collapsing rubber fuel line. Or maybe the mechanical lift pump has failed and the IP is drawing the fuel up on it's own.

 

[wakeup]

Sounds to me like it is running short on fuel.

X2
I would start with replacing the filter on the fire wall and see what that does for you.

 

[Richcz28]

Subscribed because johnnyc is my cousin.

 

[British Slave]

Injector pump. It will eventually just die and not start. Been there done that.

 

[diesel4me]

My 6.2 did about the same thing to me a few weeks ago on my way home from a dump run...started surging a bit,then stalled out slowly like it ran out of fuel..attempts to re-start it failed..I decided not to crank it too long to avoid killing the batteries..

I thought the electric fuel pump i added to the stock system near the tank died,(I could not hear it pumping with the key on--and I checked for power and it was getting 12V too)--but after I had a good samaratin get me a gallon of diesel and I dumped it in,I clamped the rubber fuel line off going from the fuel filter to the injector pump (to avoid getting air into it) and I opened the bleeder screw on the filter housing and turned the key on,and fuel squirted out after a few seconds..so evidently the pump was working..

So I assumed I had just run it too low on fuel,it was below 1/4 tank,but I have run it lower than that before and had no issues..however ,I had parked the truck on an incline just before this happened and I only made it a mile or two before it stalled,so maybe all the fuel ran to one end of the tank and air was sucked into the fuel lines??..

When I made it home I inpected all the lines and hoses to the tank--one from the filter to IP was cracked at the filter nipple,and the steel line going back to the tank was original and rusted badly,looked like it would start weeping any day--so I replaced the entire thing with copper from the tank to the fuel filter...it seemed to start faster now than it ever did,maybe due to the hot weather though..I suspect it may have been sucking air in thru rusted areas or the cracked rubber hose?..that can stall a diesel out pretty easily.

I drove it once more to the dump since then,and took it out yesterday for a ten mile run,and thought it didn't stall or surge,it does feel very gutless,more so than usual..maybe I've been spoiled by my Contour's quick acceleration,I dont drive the truck that much,and maybe I'm just not used to it,I cant say..

I am going to replace the fuel filter next,its been on it since I got it 10 years ago,,but looked "new" then,and I've put maybe 5000 miles on it in those years..its starting to show rust on the paint on it,so its probably due...and I dont see a "secondary" filter under the intake like most other 6.2's have I've seen,someone may have "deleted" it perhaps..

 

[Blue85]

Water in fuel?

 

[POORBOYK5]

Picking up air? Might want to put a clear inline filter after your main one to keep an eye on flow. See if It picks up air or runs out of fuel. Replace main filter for piece of mind, and preventative maintenance. I always keep spare fuel filters in my cummins. Diesels are weird and picky when it comes to fuel filters.

 

[diesel4me]

Could be water,air being sucked in the fuel line somewhere between tank and pump,maybe the gas cap is not venting and the fuel cant be sucked out,had my lawn tractor do just that when the little air hole in the cap blocked up with gunk,no fuel could flow to the carb with it blocked ,it ran a few minutes and died,did it several times..

I'd ensure the fuel shut off solenoid on the IP has a good connection on the wire that plugs onto it too,if it loses voltage it'll shut off the fuel...