95 Suburban, Weird stalling problem, NEED HELP!!!
 

OK Chevy guys, Who is up for a challenge? I have what promises to be a very wierd problem with my 1995 Suburban, 5.7L, TBI, K1500, 4WD. 111k original miles and in pretty nice shape.

After initially expereinceing the problem of the engine intermittantly stalling and sometimes not starting we went through a whole gammet of replacing parts. No codes, the only thing we could find was loss of fuel pressure. We replaced the fuel pump, rebuilt T-body including regulator, coolant temp sensor, EGR, ECU, Fuel filter, Cap, Rotor, Wires & plugs. Not a bad idea to replace all that anyway, but the problem still exists.

here's what happens: When backing up and turning the wheel to the right and then stepping on the brakes the engine dies. Put in park, turn key starts up. Step on brakes, engine dies. Other things I notice when this condition exists: if you crank engine with foot on brake, will not start. If foot is off brake pedal, engine starts, but if you turn lights on, engine dies. Key in "on" position and tail lamps come on (while condition exists) without turning the lights on. Fuel pressure drops to nothing when problem exists (installed in line gauge). Now, If I put the car in neutral start it up and put in drive (all while not touching the brake), move it forward and step/jam on brakes, symptoms (stalling, tail lamps on, fuel pump, etc..) all go away and the truck runs and drives fine.

In summary the motion backwards and stopping the vehicle creates the stalling/no run condition, the motion forward and stopping relieves the condition. I dont want to lead the witness per say, but I'm guessing it is electrical in nature. Any help or feedback, places to start would be greatly appreciated.

Feel free to respond or even call me at 518-258-7251https://chevroletforum.com/forum/dat...AASUVORK5CYII=

Chris

Addition: I also checked for vaccum leaks at manifold, none. Also blocked off brkae booster to elimnate. No change when condition exists.

This is just a wild guess, and I do NOT know the fix for you, but...

So many times when we hear of strange occurrences like that, it leads back (in part) to Grounds. There are several, so, take apart, brush, scrape and retighten, often times resolves things.

Good Luck.

I remember reading about some trucks that had the wiring loom rubbing on the left upper control arm. Don't remember the years but it's a simple visual inspection and I would also check back by the rear suspension and bumper. Hope you see something. Has the truck been lowered or tires changed?

Found the problem!
 

Hey guys, thanks for the help. I was speaking to a friend of mine that had a similar problem and, like SWHouston said, it is a ground problem. My friend had said he thought the tail light, brake light, fuel pump etc.. all shared a common ground. I pulled the tail light and unplugged it, grounded the ground wire and mystery solved. The only thing remaining is trying to find where the problem child is. At least I can drive the truck safely now. In searching grounds we also found the ground strap from the back of the engine to the frame was broken. More things to fix!

Thanks again for your help guys!

Back in the Points and Condenser days, we never had problems like that. I think stuff like this is equally related to the introduction of Computers in our Rides, and the extensive application of Plastic/Synthetic body components.

This mandatory running/using grounds to complete circuits has exacerbated diagnosing to a hair pulling level. I'm almost to the point where if I see a hole in the Frame, and one in a body part that's close, I'll run a ground weather I think it needs it or not. :rolleyes:

Shucks, I even grounded a Fiberglass Fender Well once.
It didn't help my electrical problem, but it stopped a rattle :D jj

PS Fatherofgirls...
On a more serious note, I'd check your Motor Mounts for excessive slack/broken, hearing what you said about that Ground Strap.