95 Chevy 1500 Pickup Stalled

[jsfinn]

Is this just coincidence?<br /><br />I have a 1995 Chevy V8 pickup.<br /><br />It was about 35 degrees outside today. I started up the truck, and let it warm up for a few minutes. I put my foot on the brake to shift to drive and as my foot went on the brake, the engine revved up to probably 1500 or so RPM for a sec and then went back down. I didn't think much of it..thought maybe my foot tapped the accelerator by accident.<br /><br />Later on, (engine warm) I was parked in front of the house unloading some things, got back in, put my foot on the break and pulled back on the gear selector to shift (hadn't shifted yet), and the truck stalled.<br /><br />It started right back up, no problem and I couldn't get it to do it again.<br /><br />Any ideas?

 

[KRS]

Re: 95 Chevy 1500 Pickup Stalled

I may be wrong, this is ONLY a guess, don't replace this part just on my thoughts.... IF the master cylinder goes bad, I *think* it will pull too much vacuum in your intake manifold, and could cause a stall or idle problem.<br /><br />Good luck, maybe someone else will know more.

 

[Reel Poor]

Re: 95 Chevy 1500 Pickup Stalled

Not the master cylinder, but the power brake booster. Sometimes they give some warning of failure ie, hard brake petal, hissing noise from under dash when brake pedal is depressed. If the master cylinder has been changed before and was leaking from the rear of cylinder some of the fluid could have entered the booster and caused booster diaphram failure. If it hasnt been changed it is probably the culprate of booster failure. The vaccum leak thru the booster could cause the engine to rev which caused the IAC to respond to a closed position causing the engine to stall.

 

[jsfinn]

Re: 95 Chevy 1500 Pickup Stalled

So, it's not revving when I press the brake anymore, but just stalls when I first start it and push the brake to shift gears. If I take my foot off the brake quick enough, the engine will start to stall and then come back. It seems fine once it gets going though.<br /><br />How good of a chance do I have that it's just the vacuum line that goes between the booster and the intake manifold? <br /><br />If that is the problem, can I just buy a vacuum hose at the local auto parts store or do I need a some kind of special hose?<br /><br />Thanks!

 

[--GQ--]

Re: 95 Chevy 1500 Pickup Stalled

jsfinn i had the same problem with my 2003 silverado. when i step on the brake or when making a sharp turn at idle speed, the engine would shut off. The problem my K&N air filter was cloged up with greasy dirt. After i washed off the debries everything went back to normal....ur truck is a 95 though so i'm not sure it would be the same solution

 

[Reel Poor]

Re: 95 Chevy 1500 Pickup Stalled

Like GQ said check the air filter. Also check the throttle body for crud around the throttle plate and clean with Seafoam/DeepCreep. <br /><br />Is the "CHECK ENGINE" light on, even intermittently?<br /><br />As far as the hose goes its probably ok.

 

[jsfinn]

Re: 95 Chevy 1500 Pickup Stalled

I don't think it's the air filter because it's pretty new. I'll check it out in the morning though. While I'm in there, I'll check out the throttle body... I've been hanging on to a can of Deep Creep for a while looking for a reason to use it! <br /><br />I just went out to take a quick look at it and though I had found the problem - there is no hose clamp on hose on the booster side, but after looking at the pictures in the Haynes manual I have, those don't have a clamp either. I thought it was going to quick and easy. <br /><br />Thanks for the advice!

 

[jsfinn]

Re: 95 Chevy 1500 Pickup Stalled

Oh, and no, the check engine light doesn't come on ever... except for maybe when it stalls, but that's probably normal for that situation.

 

[jsfinn]

Re: 95 Chevy 1500 Pickup Stalled

So the problem continues. I cleaned the throttle body and plate last weekend. It didn't look that bad but did it anyways.<br /><br />I started the truck up today, the first time since last Sunday. It was dark out, so I started it, let it run for a couple of secs, then turned on the lights and the truck stalled, radio turned off, nothing. It was like the battery was disconnected. <br /><br />I took the key out, put it back in, and started it back up. As soon as I turned on the lights, same thing. Stalled, no electricity.<br /><br />Tried to start it again, and it wouldn't crank, and the radio wouldn't turn on. Again, it was like there was no battery.<br /><br />I popped the hood, the under-hood light didn't come on. I jiggled the positive cable, and then the negative cable. As soon as I yanked on it, the under-hood light came on, and I started the truck up. Reved it up a little bit, and then everything was fine. <br /><br />So, I'm really confused. If the truck is started, and the neg. battery cable comes loose, shouldn't the truck stay running?<br /><br />I don't get it.

 

[Reel Poor]

Re: 95 Chevy 1500 Pickup Stalled

Just clean both terminals and give it a go again.

 

[jsfinn]

Re: 95 Chevy 1500 Pickup Stalled

Thanks, Reel Poor. I'll do that, but I'm still lost as to why the engine stalls when the electrical load is increased. <br /><br />I don't think the alternator is bad because this has been going on for a few weeks and the volt meter on the dash reads good. I'll check it with another volt meter when I clean the terminals though.

 

[petryshyn]

Re: 95 Chevy 1500 Pickup Stalled

Sounds like a sticking IAC motor.

 

[jsfinn]

Re: 95 Chevy 1500 Pickup Stalled

oops..

 

[jsfinn]

Re: 95 Chevy 1500 Pickup Stalled

double post - sorry.

 

[jsfinn]

Re: 95 Chevy 1500 Pickup Stalled

I bought this truck because I wanted to learn more about doing my own auto repair.. Now I'm getting what I paid for.. <br /><br />I'm not sure that this truck has an IAC motor. From what I read about an IAC Motor, it moves idle air at cold temps.<br /><br />My truck has a damper in the air intake "snorkel" that opens when warm, and closes when cold. When it's closed, it gets air from the exhaust manifold.<br /><br />The picture below isn't my truck, but the same setup. <br /><br />The silver colored hose that goes between the air intake and exhaust manifold on mine is in pretty bad shape.<br /><br />Does this configuration replace an IAC?<br /><br />If so, I understand how that not functioning properly could cause the truck to stall, but not when I turn the lights on.<br /><br />

<br /><br />Anyways, thanks for all the tips. <br /><br />I'm going to go out and tinker with it in a little bit. I'll post back if I find anything.

 

[Reel Poor]

Re: 95 Chevy 1500 Pickup Stalled

Originally posted by jsfinn:<br /> <br /><br />My truck has a damper in the air intake "snorkel" that opens when warm, and closes when cold. When it's closed, it gets air from the exhaust manifold.

You are correct on operation of that valve but it does not replace the IAC motor.<br /><br />

The silver colored hose that goes between the air intake and exhaust manifold on mine is in pretty bad shape.

Its not absoloutely necessary. That hose and valve setup is for subfreezing temps. It allows the engine to inhale warm air off the exhaust manifold instead of the subfreezing air in the engine compartment.<br /><br />

Does this configuration replace an IAC?

No<br /><br />Here is what the IAC on your truck looks like. Its screwed into the throttle body. You can remove and clean it also.<br /><br />

<br /><br />From what you said about the battery cables I really suspect it was a voltage problem (ground ckt) to the ECM. By cleaning the terminals I beleive you will cure the problem.

 

[PierBridge]

Re: 95 Chevy 1500 Pickup Stalled

<br /><br />So, I'm really confused. If the truck is started, and the neg. battery cable comes loose, shouldn't the truck stay running?<br /><br />I don't get it. [/QB]

Of course not.<br /><br />So you found the problem, now take it to someone who can fix it for you, it will take them about 5 minutes fix your problem.<br /><br />Good Luck.