Dies And Restarts.. Some Advice Please?

plainvanilla · March 23, 2008

this has been going on for 2 weeks and it has happened about 4 times in under 500 miles of in town driving

driving along 35 mph on city streets it just dies, coast to the curb, put it in park and it restarts right off the bat like no problem.

today it did it again, but wouldn't immediately restart. After about the minute it took me to push it to the curb it restarted like nothing wrong.

It won't set a code.

I was thinking fuel pump, but now I'm not. Usually the fuel pump gives little or no warning and then won't restart at all.

I'm going to put a fuel pump relay in tonight just to see.

But without a code, I'm lost.

Right before this started, I used a can of BG intake cleaner, but it drove good right after that, so I don't know.

Also, I have had a couple of times where we don't drive it for 3 days and the battery seems a little low at first crank, but I think that is unrelated.

Its a 2002 Chevy Suburban 2500 4X4 with the 8.1 and 105,000 miles on it

Does anybody have any suggestions?

TexasAl · March 23, 2008

I'm 99.9% sure that it is fuel related problem. I would first replace the fuel filter. It is probably clogged, and your fuel pump is overheating, and shutting off, or it is simply not getting enough fuel to the engine. You may have problems when your tank is less that half full. This happens because the fuel is what keeps the pump cool. Don't replace the fuel pump until you get the fuel filter replaced. -Al

TexasAl · March 23, 2008

The BG intake cleaner probably loosened some stuff in your tank, and clogged the filter.-Al

plainvanilla · March 23, 2008

The BG intake cleaner probably loosened some stuff in your tank, and clogged the filter.-Al

it was intake cleaner, I sprayed it into the throttle intake so it never affected the fuel tank in the back of the truck. I have however recently ran some fuel system cleaner through the tank.

The thing I always remember is that the fuel pumps have a tiny mesh sock over them that pre-filters the fuel for debris. But the low fuel pressure could case the motor to just up and die and it does have a tendency to do it going around turns at low speed while your off the gas.

So I'm heading outside to do the filter now.

mxrider5 · March 23, 2008

nre model trucks DO NOT have an external fuel filter. Only in-tank.

TexasAl · March 23, 2008

Ok, I get ya. Well, I helped a budddy of mine with his TransAm, and I ended up buying a set of fuel pressure gauges from harbor freight tools. They where very cheap, and verified the problem for me. You may want to get yourself a set of those gauges and make sure your engine is getting the fuel it needs. His fuel pump would heat up if there was less that half a tank, and then start to get weak, and then cut off. His pump would not start working until it cooled off, so it sounds different than your situation. Good luck, and I hope that filter is the problem. If it isn't get a set of gauges, and check the fuel pressure when the truck does not start. Good luck

-al

TexasAl · March 23, 2008

What is "nre"? The problems are on his 04 Suburban. I believe they still have an external fuel filter.

-Al

testdrive · March 23, 2008

Do a search on crankshaft sensor and 8.1... GM might just replace it free of charge if your VIN is in the list of known bad ones.

plainvanilla · March 24, 2008

nre model trucks DO NOT have an external fuel filter. Only in-tank.

this one had it on the frame under the drivers seat

plainvanilla · March 24, 2008

Do a search on crankshaft sensor and 8.1... GM might just replace it free of charge if your VIN is in the list of known bad ones.

hey thanks, never thought of that.

Would it not set a code either?

Whatever is causing this isn't setting a code

BTW, the fuel filter looked pretty bad

It was an aftermarket, so it had been changed at least once before I got it.

But I replaced it, cut it in half with a metal saw and pulled out the element.

It stank a little, like rotten. Mabey some water had been in there??

But it was plenty dirty, still don't know if it was bad enough to cause this problem.

TexasAl · March 24, 2008

I think the crankshaft sensor will leave a code. I've had one go bad on a Grand Prix, and it did leave a code. Get yourself a set of gauges, and check the fuel pressure on the truck after driving it for a while. I'm thinking it may be a dirty fuel filter or a weak fuel pump.

-Al

plainvanilla · March 24, 2008

I read up the the 8.1 problems with crankshaft sensors and many times the owners are saying no code sets until the thing goes completely out.

I changed the filter and I will drive it around town this week and see if it does it again.

If it still does, I think I will go with a crankshaft sensor.

I can located it, but does anyone here know for sure if it is just a r & r or does something extra have to be done when you replace one?

plainvanilla · March 26, 2008

update

I never installed a crank sensor after all.

You almost have to have lift to get to the back of the motor where it is and I convinced myself it wasn't the problem.

over the last few days it stalled more and more but restarted and took longer to restart.

I'm 90% sure it is just the fuel pump worn and not giving enough sustained pressure to the fuel rail to keep it running.

That truck needs 55-65 PSI at the fuel rail just to run. If the pump is getting weak, and the pressure dips, the motor just dies quickly.

I don't have the time to mess with it and I really don't want to drop that tank, since I crawled under and seen where it is. That Suburban has two tanks.

A small one in the rear and the front larger tank. The back one senses when the front one will hold more and a pump kicks in and refills the front tank.

Weird.

Anyway, if it turns out the be the pump, it's nothing that 6 or 7 hundred won't fix

plainvanilla · May 3, 2008

Guys I'm about to burn this truck to the freaking ground!

It has been over a month of this crap and I can't figure this out.

I took it to a good shop and it would not die for them after they drove it for an hour

They did hook up a fuel pressure gauge and let it run while hooked up.

They fastened it under the passenger side wiper so you can read it while driving and it was running on only 45 PSI, which in theory it shouldn't

the book says 55-62

since they couldn't get it to die and read the pressure while it happened I just picked it up and we decided to keep it until it quit or became more frequent.

After two more weeks of it dying intermittently, and still running on 45 PSI, I made the choice to go ahead with new Delco fuel pump, since it has 105K miles on it. I figure, if it fixed the problem great if not, then the pump is one thing I don't have to worry about for awhile.

didn't fix it. but now it does have 56 PSI of fuel pressure.

Two more weeks of dying out, now it does it more in traffic at stops and pulling into parking lots.

So today I figured I would try a new TPS, since they can cause this without setting a code.

no joy

If the darn thing would set a code it would be nice.

I just don't know what to do.

I don't think it's the security feature in the column because when it dies the security light does not come on.

It just sputters and dies and won't restart right off the bat, usually takes a minute before it recranks.

when it decides to run, it's fine for several miles again

sometimes going a day or two between dying out.

any ideas???

Please!!

bert55441 · May 3, 2008

I have a 2002 GMC Sierra with the same 8.1 and I had the same stalling problem. I cold go a block away or miles and it would stall at different time. My truck never gave a code and the only light that would come on was the red battery light. It drove me nuts too until I found this site and changed out the crank position sensor. Its a PITA to get to but I think this will solve your problems.

Hope that helps