Mustang Dying Issue

98modmustang

98modmustang

Forum Member
I have a 1995 Mustang GT and It wont stay running. Here is what is done to the vehicle BBK long tube headers, Trick Flow upper and lower intake, Trick flow 75 mm elbow, summit 75 mm throttle body, Ac delete, Smog pump delete, e 303 cam, MSD coil, MSD cap and rotor, MGW short throw shifter, BBK cold air intake, Flowmaster Mufflers, BBK Fuel pressure regulator, Russel Fuel Pressure Gauge, BBK under drive pulleys, BBK Lowering springs and I think that is about it. What happens is if I keep giving it throttle then it will stay running once I let it idle it will idle up and down and then die. It will also die at a rolling idle. the fuel pressure is about 40 psi. I was thinking it is the IAC but I am not sure. What do you think it could be? I have cleaned the IAC and the MAF. Any suggestions? Any other questions feel free to ask.

Thank You
Sam
 
Sounds like you have a vac leak or a leak after the MAF (unregistered air), I had a similiar problem when a vac tube came off my powerpipe

You can also clean out your IAC but I doubt that's the culprate
 
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I checked for a vac leak and Didn't find anything I can look again I am not sure what a power pipe is. and I just took the upper intake off and replaced some of the vac lines. It was doing this before I got the car and It is killing me cause I cant find the problem.
 
I also Cleaned the IAC once and it didn't do anything and also when I start it up when it is cold it will run longer and have less up and down idle then once it warms up it goes up and down a lot and then it dies.
 
sounds like you need a tune... try running it with the IAC unplugged and adjust idle to about 650-700 rpm, then plug the IAC back in. It should increase the rpm to around 1000. Also the TPS should be at just less then 1 volt(.98,.99) KOEO no throttle. this might help the idle issue. If not, and no vaccuum leaks are present then you will more then likely need a tune.
 
it could be a number of things, vacuum leak, iac, tps sensor.
if it runs longer when it's cold chances are it a vacuum leak somewhere cause it runs a lot richer til the motor gets up to temp and then goes into closed loop operation where it then uses premium settings for your timing and fuel enrichment.
if you took the intake off did you put in all new gaskets on the top end.
also check you pcv valve in the back of the intake.doubt thats the problem but ya never know.
usually if it's a vacuum line the motor will just idle rough and vary in rpm a little. if it's a big vacuum leak then the motor will die like that.
make sure your tps is set between .095-.098 volts at idle.
 
The Engine light is not on.

When I unplug the IAC the car dies instantley and then has a hard start.

Like I said I looked for a vac Leak again and came up with nothing. But there is a green line, and red line, and orange line that seems to be for a vacuum. When I unplug the red line that runs to the PCV line the runs into the Elbow the car will idle and idle fine. So I dont know what that means it seems like it is not getting enough air cause it has the faintest smell of to much gas. I will go check the TPS right now and let you know what I find.
 
98modmustang said:
The Engine light is not on.

When I unplug the IAC the car dies instantley and then has a hard start.

Like I said I looked for a vac Leak again and came up with nothing. But there is a green line, and red line, and orange line that seems to be for a vacuum. When I unplug the red line that runs to the PCV line the runs into the Elbow the car will idle and idle fine. So I dont know what that means it seems like it is not getting enough air cause it has the faintest smell of to much gas. I will go check the TPS right now and let you know what I find.
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Bad PCV? If you change vac. source and car idles good then I would assume the PCV is bad or plugged
 
Thats what I was thinking I cleaned the PCV and tried it agian didn't do anything also I pulled the PCV out and while it was running put my finger over it and nothing happen. But I could be the PCV I am going to check TPS voltage right now
 
i would agree with that also. do you know how to check the pcv valve?
also try unplugging the vacuum line to the FPR. while its running.

don't mess with the TPS. it's obviously in the vacuum lines. if you unhooked a certian line and it idled fine then it's in the vacuum somehow. nothing to do with the TPS. and if it was the red line you unplugged i believe that one goes to the FPR or the EGR. not sure on the 94-95.can't remember.
 
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98modmustang said:
I am not sure how to check it any info on that or did I do it correct?
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what are you trying to check? if it's the fpr. then just unhook the line going to it. and then stick your finger over the end of the line to see if it's pulling vacuum, or not.if you go through and unhook one thing at a time you'll figure out the problem eventually.
 
Yes I check the FPR and did that I also replaced it with the stock one just to see if it would make a diffrence. Also Like I said when you unpluge the red hose running to the elbow then the car will idle ok but still has a little up and down idle. It really seems like it is just not getting enough air. But I am not sure what that line does ( the red lin running to the elbow). I put a good PCV valve in it and it did not change a thing.
 
I can't figure it out I am going to try to adjust the TPS tomarow and hope that works. I am really at a loss here. Everything that I have done so far hasent done anything besides un pluging that red line from the PCV valve line that is the only thing that will alow it to keep running and it still idles up and down a little bit. And then since I have created a vacuum leak the car dies when I snap the throttle.
 
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