Diesel Place banner

'94 Suburban doesn't want to start, or stay running when it does.

2K views 13 replies 10 participants last post by  Freddyack 
#1 ·
Hello everyone,

I've browsed this forum some time, and it's helped me repair quite a few issues on my first 6.5l vehicle ('95 suburban k2500), and since I liked the first one so much, I decided to pick up another that I could use as a beater (it was insanely cheap for a running truck at only $800, and I figured it could be a fun project). It ran great at the time. Started on a dime in the cold, and had no problems I could notice, other than a beat to hell interior. The previous owner had recently had the turbo rebuilt, and put on new injectors as well.

The day I bought the car, my wife and I decided to let her sister use it for a little while, so we dropped it off for her, and headed home. Well, the next day, her boyfriend poured ATF into the fuel filter housing, thinking it would refill the transmission, which was a little low at the time. After that, they left it idling to warm up inside, and it died after about 15 minutes of that. It wouldn't start up again, and was leaking fuel from somewhere behind the engine when it got cranked. I didn't want to work on it out front of their house, so I towed it home.

That was about a year ago, and I've been too busy to work on the truck until now, so yesterday I had some spare time, and thought maybe I'd try to get it running. I replaced the batteries, tightened up the fuel filter (which did quite a bit to rectify the fuel leak, but didn't fix it entirely) and replaced the glow plug relay (the 'wait to start' light wasn't coming on). Unfortunately, I still really doesn't want to start.

After doing all those things, I tried plugging in the block heater (even though it was 80f today), and spaying a little starting fluid in the air intake. Well I finally got it to start for a second after that, but it spewed white/bluish smoke, stuttered quite a bit, and then died. I've since tried starting it a few times since. It starts about one in 10-15 times, and when it does start, it smokes like a mother, stutters, and dies after 10 seconds.

It cranks just as quickly as my running truck, but it just doesn't want to start. It's throwing codes 57 and 62, neither of which seems like it should prevent the car from starting, but what I'm no mechanic.

Here's a summary for anyone who didn't want to read that all:

-bought 94 suburban k1500 with rebuilt turbo and new injectors

-lent it to sister in law

-her boyfriend filled the fuel filter housing with ATF, trying to fill the transmission.

- They let it idle for 15 minutes after that, and then it died, and refused to start again.

-Large fuel leak from behind engine when cranking

-The truck sat for a year while I was too busy to work on it

-Today, I started working, and replaced the glow plug relay, batteries, and tightened the fuel filter down. Fuel leak reduced, but still no start.

-block heater and used starting fluid caused it too start, but it spewed white/blue smoke, stuttered, and died after 10 seconds, even with my foto on the accelerator.

-Starts maybe 1 in 10 times now, but never runs more than 10 seconds (poorly).

-Throwing codes 57 and 62


Any help is appreciated folks. I've got a '95 suburban k2500 that I use as my winter vehicle, so I can switch parts back and forth between the 2 trucks, if anyone has any ideas what parts I should try switching.
 
See less See more
#2 ·
Have you checked the condition of the fuel filter? Sucked all the nasty out? Does the lift pump, pump?
 
#3 ·
Welcome!!!

If the fuel is leaking from behind the engine, that means it intro air into the fuel system.
That by itself will cause it not to start.

How did they fill out the fuel filter with trans fluid? That part I don't understand.

Anyway, the Lift Pump in this truck is run by the Oil Pressure Sender.
If OPS is bad, the LP will not run and it cause inability to start especially when there are air in fuel. Sounds more like the ground is wet or something from the fuel leak.
 
#4 · (Edited)
You said fuel leak reduced. If its still leaking fuel from the fuel manager it may be also be letting air in preventing it from starting/running. ( as said above) Pull the top off the fuel manager and see if the gasket is still there. Might have fallen out or been damaged, when ATF was added to the transmission & injection pump filler.. LOL
Might as well change the fuel filter while you are in there. They come with a new gasket.
 
#5 ·
You have air entering the fuel line system at some point. Since the boyfriend messed with the fuel filter I'd start there. It is pretty easy to not get them on tight enough or misaligned, especially for someone that knows nothing about it. Hot wire the LP so it pumps fuel and inspect where the leak is. Fix it and it should be running like it was when you purchased the truck.
 
#6 ·
hello and welcome.
sounds to me like there is way to much ATF in the fuel.

#1 DO NOT USE STARING FLUID, even just a bit can damage the glow plugs, that being said I would change the fuel filter, make that leak stop. That will stop the air from getting in. when you change the filter make sure the canister is clean and fill it with fresh clean diesel. Then I would open the bleeder tee and either run the lift pump or crank the truck till you get nice clean diesel out of the bleeder.

After that I would crack all the injector lines free and bleed all the air and ATF out of the system (you can do that one at a time, a few at a time or try for all at once). once you get nice clean fresh fuel tighten them down and see if she will go. you will have a bunch of fuel in the injectors themselves but you should be able to push that into the combustion chamber and then it should go.

note**** you should never crank the starter for more than about 30 sec at a time otherwise it gets too hot and swells and will tear out the starter.

also don't forget to top up the tranny and smack your brother in-law.
 
#7 ·
That guy sounds like a future Darwin Award contender. Better check your transmission to see if it has diesel in it...
 
#8 ·
Dont use starting fluid, youre better off blowing a heat gun down the intake if you had to. You may be needing a ops and ip is sucking air right now. FFM needs to be not leaking. Youll get it to start. One thing at a time though. Start by sealing up that FFM then move on to the "Lift Pump Test" in the faq. 94 & 95 Need the ops circuit modified to power the lift pump for reliability sake. Welcome to Dieselplace.
 
#9 · (Edited)
A 95 is very easy to override the oil pressure sensor and fuel pump relay by jumping the contacts in the under hood fuse block for the fuel pump relay. This will help you test the pump and purge any crap or air out of the system before you try to start it again. As others have suggested, there is a relay mod for reliability but this is the FREE troubleshooting before you get into buying any parts!

Part #'s for fuel filters, and the two o-rings to rebuild the filter housing are in the FAQ.

PM me if you need any help with that during the process. I have a photo on my phone I can send you.
 
#10 · (Edited)
I missed the 57 and 62 codes.
57 is PCM 5 volt shorted. All the sensors in the engine including the APPS use that 5 volt line. This code will cause all kinds of drivability issues and no start.
62 Boost sensor low voltage. PCM is not seeing the voltage it wants from the boost sensor.
Possible short in boost sensor itself or somewhere in the 5 volt line going out of the PCM to all of the sensors. Check connections and grounds. did you check the ground on the back of the passenger side of the intake? Its the main ground for the PCM. it gets loose or sometimes one of the small black wires will break off from its connector.
 
#11 · (Edited)
Thanks for all the replies folks! I did manage to get the truck running this afternoon! I replaced the fuel filter, siphoned out the housing and cleaned it, bled some fuel out of the t-valve until it was running clean (I think the PO had been running farm diesel in ti because it's dyed red, and I never put any fuel in the truck). it's still throwing the 2 codes so that's next on my list, but I'm just happy it's moving under it's own power now. Does anyone have any idea how to test the boost sensor?

Thanks again for the help!
 
#12 ·
I'd check grounds as suggested and use GMTDScan Tech software to figure it out. It's cheap in comparison to head-scratching. You might even be able to get enough out of the free version to troubleshoot your sensors and wiring.
 
#13 ·
Glad you got it running. Before chasing codes. I would clear the codes, drive the truck and see if any come back. They just could be old codes stored in the memory.
 
#14 ·
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top