Car dies when I come to a stop
 

My 93 GT just dies when i come to a stop from driving it. It doesn't sputter or miss, or act like fuel. It just dies very suddenly. Then I start it right back up and it drives normal. Also the Check engine light and Battery light come on when it dies. But both go away when i start it back up.
What could it be, its happend to me 3 times already

Also my clutch pedal has been clicking off and on for months now, when i press in.

Do you have an aftermarket cam?

Thanks,
DoranW

no
 

Stock cam. I have the idle at 750-800rpms

Could be a sticky EGR valve.

Take care,
~Chris

or a sticky IAC

True, but as the engine warms up, it relies less and less on the IAC. Still, worth looking at.

:)

Take care,
~Chris

getting worse
 

Now the Battery light is flickering off and on, everytime i drive now. And it died again. The alt gauge is normal all the time

replaced the IAC
New alternator
New battery

could it be a short somewhere?

Have you checked your TPS voltage? It should be between .90-.95V or so. Check it across the green and the black wires with the key on and engine off.

Also, try unplugging your EGR valve and driving it. It may throw some codes at you, but you'll be able to see if thats the culprit or not.

hmm
 

unplug where? the connector on the back? TPS voltage at .98 volts. Would that make the battery light flicker? heh.

What is the voltage at the battery when the engine is off? Engine running? Engine running with headlights on high, a/c on w/ fan on high?

To check and see if it's the EGR, you would need to unplug the vacuum hose, not the electrical connector, and plug it.

:)

Take care,
~Chris

The alternator was bad, i just replaced it. But the car died on my again today, i guess thats not the problem. But this time it died, it too longer and i had to gas it to keep it going but it died still. :(
also replaced the IAC.

Don't stop.

That was a easy one, next question please.

Check your fuel pressure.

hmmm
 

Fuel Pressure Regulator is at 40.5 Psi with vacuum off.

I was at the Dyno Yesterday and put the pressure down from 42psi to 40.5psi. and i made 3ft-Lb's of tourqe more than at 42.
and they said my A/F was 12:1 at 42psi

Whats funney is my stock regualtor runs at 45psi vacuum off.
I did a whole lot of mods. Then had to get a adjustable FPR to back the pressure off LOL.

And it's still stalling when you come to a stop? Does it do it every time, or only when getting off the freeway, lets say?

What happened with the EGR valve test? Does it still stall with the EGR vacuum line disconnected? Does it start hard or start right up after it stalls?

You mentioned your clutch pedal clicking. Does it shift hard?

You may also want to make sure that your plug wires are secure. If one is loose, it could be moving forward as you brake causing it to arc on a header.

Are you running your A/C? Does it matter if your A/C is on or off?

Fuel pressure will only affect air/fuel ratio until the computer adapts. 45 isn't all that high and dialing it back wasn't really necessary, but getting a new FPR probably eliminates that as a potential problem. Sorry, it's just a pet peeve with me. Especially if the guy at the dyno leads you to believe that you can adjust your air/fuel ratio with an adjustable FPR.

still dieing
 

JimBerg:

THe car runs like normal when the EGR vacuum line is off, doesnt die. All new wires and plugs also.

The last 3 times the car has died, The AC has been on!!! The last time it died, i was going 30mph, when i down shifted into 4th.
I turn the AC off and it starts right back up and goes normally.

Re: still dieing
 

Don't overthink things. Read the line above that YOU wrote.

Now with the vacuum line off, if you mess with the A/C and all the other things and it still doesn't die, then you're going right past the problem.

Dude. Come on. You're not gonna make me draw you a picture too, are you?

:D

Take care,
~Chris

If you have a vacuum gauge, hook it up to the line going to the EGR valve. It should read 0 vacuum at idle. If it doesn't, you need a new EGR vacuum regulator (EVR) solenoid (It's mounted on the back of the passenger side strut tower), if it does read 0, you probably need a new EGR valve.

As for the A/C being on, that was just a question to consider if the EGR valve test yielded nothing. It definitely sounds like the EGR test yielded something, so you should fix that before moving on to something else.

Let us know what you find out.

ok
 

OK, tomarrow ill run the tests you told me to do, I have vacuum gauge. Im pretty sure the AC is involved, becuase everytime its on, it dies, and when its not on it doesnt seem to die. Ill let you guys know about the vaccum tomarrow afternoon. thanks! :)

hmm
 

OK just did the vacuum check. It reads 0 at idle and 0 with engine rev'ing. My father was thinking it might be the AC, idle compensator, but the dieing problem is so random that i cant tell.

Also what vaccum psi should the manifold be at at idle?

You guys have any other ideas let me know.

Let me explain this a little better. Your EGR valve is sticking open at times, which is fine when your driving, but when you come to a stop, it leans out the engine, and it stalls. It sounds like it's at the earliest stages of failure, so something as simple as manifold vacuum can cause the valve to not close all the way. That's why it restarts. The AC puts a load on the engine, so anything that might make it stall, will make it stall if the AC is on. You already tried unplugging the EGR, and you said it never stalled when the EGR was unplugged, but it did stall when the EGR was hooked up. The vacuum test you performed tells you that it's the valve that's sticking, rather than the solenoid that controls the vacuum to the valve. Time to replace the EGR valve, and make sure you clean the mounting surface, and use a new gasket.

:)

Take care,
~Chris

heh
 

I never drove the car, with it unpluged! You mean the connector unplug on the EGR right? Ill go try that now and run the AC and see if it dies when im driving. Ill let ya know! Sorry Im slow on this sorta thing, First Fox body mustang!!!

No, not the connector. You HAVE to have that plugged in. He's talking about the vacuum line. If it runs well with it disconnected, just leave it disconnected.

I wouldn't say you HAVE to have it plugged in. I've had mine unplugged for about 2 years now, and its always ran great.

I have heard that it will throw codes, and possibly cause idle problems, but its always been fine on my car.

It forces your car to run in a limp mode. Sure it will run, but it won't run well. It may actually force your car to stay in open loop mode. but I'm not sure about that. Maybe Chris can shed some light on it.

OK, drove it and made 6 or 7 sudden stops with the AC on, Only the Vacuum line off, and plugged the EGR port and vac line.

Before I unplugged it, the car died once with the AC on.
After i unpluged it It never died! But, it almost did once, RPMs dropped to 400 and came back up, but didnt die. So i guess ill leave it unpluged and drive it a while :) Thanks guys! I'll see how it goes, otherwise ill be back POST'N UP! ;)

Whats the point of the EGR anyways? My Check Engine light is NOT on! haha

The electrical connection on the EGR valve is the EGR valve position sensor. It provides feedback to the computer to let it know that it's opening and closing when the computer opens and closes the EGR vacuum regulator solenoid. The EGR valve is what allows exhaust back into the intake to be burned to reduce emissions. This also helps keep combustion chamber temps down to reduce problems with detonation and reduce NOx emissions.

Where are you at this point? You have the vacuum line disconnected, but the electrical connector still connected? If that's not where you are, that's where you should be. The electrical connection doesn't control the opening and closing of the EGR valve, but the absence of its signal could cause problems.

If you don't want to spend the money on replacing the EGR valve (I think I may have one that I can send you, by the way), you could just fabricate a plate to mount between the EGR valve and the EGR spacer. This would block the exhaust completely and fix your problem if the EGR valve is sticking open a little bit. You could do this until you prove it's the EGR valve causing the problem and then know that money spent on a new EGR valve is worth it.

ok
 

I have it where you said. But im going to pull the EGR valve out and try cleaning it, with carb cleaner, maybe soaking it in some gas. And if that doesnt work i can make a solid gasket to put inbetween the EGR and EGR plate. Ill try these things, and let ya know! thanks for the help guys.