Arg. Need help with car problem.

[Cygnus X1]

I'm on the chat over at MonteCarlo SS.com, trying to get help on an engine stalling problem. Place is dead right now.

88 Chevy full size van, 350 throttle body, stalls while running. No overheating, no codes, not stumbling, runs smooth, but just stops while under cruise.

Changed fuel filter, problem still remains. Where do I start troubleshooting when it sits at idle and runs just fine?

Thanks all....

[Jason1212]

Does it only do it while it on cruise or does it do it all the time. When was the last time you replaced your wires and cap?

[Cygnus X1]

Jason,
please go to chat.
Thanks,

[Jason1212]

I am at work and the fire wall will not let me. Sorry about that.

[Cygnus X1]

Yeah, I have to go to work. Working nights this week. I'll check back.
Thanks again.

[GWARGHOUL]

Hows your throttle body diaphram?

[ADR]

Cygnus X1: First thing I thought of was fuel pressure. TB should have a electric fuel pump,may have enough pressure to start and idle but under load starving for fuel.
Dont believe it has a TPS, thought you could have a flat spot and ECU sees no voltage thus stalling the engine. Only other things I can think of is stuck EGR valve or possibly (if it has one) clogged cat.
Cant recall how to check proper fuel pressure on TB's? My 85 Monte SS had a Carb and my Grand National has Seq. Fuel injection.
I was going to suggest a bad MAF sensor but it doesnt have one right? Speed density sensor?To check for a bad MAF, just tap on it with a handle of a screw driver while running,if engine stumbles its bad.
If not anything mechanical. . only thing left is Computer/PROM chip. Once again sounds like fuel problem, is the fuel pump humming loud at all? They usually get pretty loud before they go.

[RacerX]

I think it's the muffler bearings

[Razor]

Definitely run a fuel pressure test and see if you aren't tapering fuel pressure off during stall tests and over a period of time (can do while idling).

Does it happen while you're at cruising speed, or did you mean that it dies only when in cruise control?

It should have a TPS and I agree the MAF could be suspect too. Something simple that I've seen over the years is a piece of trash like a small leaf, leaf stem or piece of fuzz on the MAF element that will cause intermittent no run but not set a code. It'd be real easy to check the MAF just to rule it out.

[CharvelRocker]

I'm assuming this thing has fuel injectors right? And is it stalling when you idle or let off the throttle and let the RPMs go all the way down?

[Cygnus X1]

Thanks all, I'll check the pressure tomorrow. It's a throttle body, not TPI.
Also have an 87 Monte Carlo SS, cool car. Pix are in this forum, from last week.
The fuel pump is quiet, thank goodness. I hate to have to drop that 35 gallon tank to get to it. (Assuming it's inside, like most).
She doesn't use cruise control, and A/C was off. Happened both under decel and while running 45 mph, part throttle.
I've not done any work on this van yet, except oil change.

Racer X, everyone knows the first thing to replace when getting a used vehicle is the muffler bearings. Sheesh....can't even trust new ones.

[~K~]

We had a chevy s-10 yrs ago that would stall out going from driving into a cruise (happened a lot on off ramps) It turned out to be something with the torque converter. I don't remember if it was that torque converter directly or a sensor attached ...hope this helps ya

[Razor]

I would say if the motor is stalling out when you come to a stop or slowing down to a rolling stop especially when hot that you could have a torque converter clutch or torque converter clutch solenoid failure. Doesn't sound like the problem you're having, but anything is possible and that kind of problem WILL NOT set a DTC on a 92 and back GM with a 700R4 tranny.

Normally when that happens, especially in older GM trannys, once the TCC solenoid sticks then even when you stop and put it in park and then go back into gear it will kill the motor because the torque converter clutch is locked in (applied) and the motor can't overcome the TCC stall at idle and low rpm's.

We're seeing a lot of fuel pump problems on Nissans here lately, and they'll intermittently lose fuel pressure and basically float/load in and out to the point where they won't take any fuel at anything over very (and I mean VERY) light throttle.

[Cygnus X1]

Started to pull the doghouse off today. I have an even bigger problem
than I thought. Some yoo-hoo hardwired the stereo and power booster
into the console face, no way to get it off without tracing everything and installing disconnects. Sweet wife drives this thing most of the time. It's her
revenge against the various Escalades and other behemoths at the school.
Ha! It's bigger than yours, eats more gas, has more toys in it and it's PAID FOR!. So she's whining about having to drive the Maxima. Guess I'd better just rip the stereo out and get it back running...
She's not going to get it back this week anyways, too much for me to do,
too hardheaded to take it to a garage just yet.

[jacksoncsplayer]

Cygnus, I had and 87 Camaro that did the same thing nd one day it finally died on me. It was the ECM. It would stall for no reason and under no specific driving conditions. Ya may wanna have that looked at.

MD