* * 1g Help Please !!!

[TonyM2487]

Hey everyone i really need some help with my 91 1g talon i have had talons b4 and have never had problems like this but this one i just cant fingure out. A little about the car it is a 91 talon that i have put a 90 gsx motor in it and has had a redone head, also the car has a stock motor with a 16g turbo, injectors, FPR, boost controller, full 2.5 inch exhaust and safc and a few other little things. So my problem is that i cannot get the car to idle it will start up fine and shut rite off. Some of the things i have tried is, Changed the cam sensor, i have tried 3 or 4 different MAF sensors including the gm mass translator and sensor, i have tried the stock ecu and the ecu from the 90 gsx where the motor came from. Also i have tried to mess with the safc,,,i was able to get it to idle once or twice but no where driveable and it ran super rich i have also tried logging it with mmcd and the car doesnt pull any codes which doesnt make any since and it seem that nothing i do makes any kind of differece i have talked to a few different ppl and no one can really give me a clear idea of where my problem is so i came here in hope to find an answer...If someone can help me out that wud be great i really want to get this thing on the road i have been working on it for some time now and just cant get it going PLEASE HELP !!!!

 

[mcarruthers]

Have you done a boost leak test?

 

[TonyM2487]

Well thats my problem it wont idle at all really its like you turn the key to start it and it starts rite but and shuts rite off its like turinging the key on and off,,,and the few time i was able to make it idle was after playing with a bunch of things and the idle was high and low and surging and not surging its all over the place

 

[thom2white]

Be sure that the SAFC airflow signal is set to Karmon. Also, check your fuel filter. It is possible that you are clogged up but not stopped up, in which allows enough fuel for an initial start, but not a maintained idle.

 

[TonyM2487]

Yup i have set the safc to karmon, i have not checked my fuel filter which im going to do because the car did sit for a while with gas in it but also if i start it up and rev the hell out of it i can keep it running but as soon as i let off it shuts rite off

 

[DSMified92]

u might want to try the TPS cause if u got it to idle a couple ties but it was irradicly then thats the TPS.if its closed up then when u start it up it will die automaticly cause its not opening up so try that

 

[tsiboostin]

Depending on how long it sat with gas in it, I say pull the full pump and make sure the sock filter isn't clogged. Took me forever to find out this problem on mine. The gas tank was rusted out, dropped in a new tank and a new sock and everything ran fine.

 

[mitsu93gsx]

ECU I had a issue almost the exact same thing, Threw a different ecu in it and cure the prob,, you dont happen to have a different ecu..

 

[solidviper89]

seems like one of your sensors is bad... and like mitsu93gsx said maybe your ecu is out... might be that the caps are out on both ecus?

 

[TonyM2487]

Wow those are defently somthings that i dident think about,,,but i have tried 2 ecus and the one from the gsx seemed to have better luck and the gsx ran b4 the motor was pulled out for swap and head rebuild,,,as for the TPS i do get a readings on the safc when i hit the throttle but im not sure if its rite ### it seems to be all over the place and if that sensor or any other sensor was bad wudent it send a code to the logger when i have it hooked up..But i will defently be checking the sock in the tank and the filter in the engine bay,,,but somthing else i did notice was that when i had the car running or tring to run i was reading 3 KAR wut ever that is even when the motor was off and it doesent really seem to move much unless i rev the hell out of it or if i have the GM MAF hooked up

 

[thom2white]

Hey Tony, I got your message. The first things I would be would be start with would be the simple ones. Run a static boost test first, If your unfamiliar VFAQ Site - Visual Frequently Answered Questions has got some instructions on how to build a tester, but it's really pretty simple. Critical step though is to set the motor up at about 30 ATDC shut the intake valves in order to pressurize the manifold to check the PCV.

Check the fuel filter as mentioned before, just pull it and see if you can blow through it. If you don't know when it was last replaced it isn't going to hurt anything to go ahead a get a new one.

Pull the ISC stepper motor out of the throttle body, with the harness hooked up, have a friend turn the key on and pay attention to the tip. It should move in and out with a slight rotation. You can always pull the testing specs from a repair manual and test it for resistance. This is the device that should keep the motor running properly at idle. If it is malfunctioning, the ECU will not through a code, because it is just a stepper motor, it never sends a signal back to the ECU.

Lastly, try and find a functioning MAS and swap it out. Are you on a GM sensor? And is the translator dialed in correctly. I don't have much experience the MAF-T, so you may need to do some research on that.

Has the car run good with the current modifications before or is this a first time build?

The surging you are talking about is usually acclaimed to boost leaks, air metering issues, and/or malfunction ISC motors.

 

[TonyM2487]

Great I really appreciate all the help im getting and hopefully this weekend ill be able to check all the things listed above and get back to everyone. I really hope that somthing above helps because i am starting to lose hope on this one

 

[DarthBulk]

Definitely check your ISC. The idle on my Talon went away a couple of months ago. I would start the car, and it would fire fine and then immediately die. I could keep it running by slightly holding the throttle down, and it ran fine while driving, but as soon as I took my foot of the gas pedal it would immediately die. I tested the resistance across the pins on the ISC, found one set of them was bad, and bought a new ISC. I installed it, started the car, and all was well again

 

[TonyM2487]

Ok so i messed around with the car for a while today and founf that the metal hose that comes off the fuel pump was broken so i changed that with another one that was good also messed around with the safc setep and the wires you have to swap in order to use the gsx ecu and was able to get the car to surge like crazy around 1200 to 1500 tried to check for vaccum leaks by spraying starting fluid around the hose and did not find any leaks but still was not able to get the car to idle normal,,,i did check the Ohms between the ISC and found it to be 38 on all termanls but im not sure if thats a good thing or not so that was it for today hopefully i can get back down there tomorrow and try some more

 

[awdmonster1904]

Well thats my problem it wont idle at all really its like you turn the key to start it and it starts rite but and shuts rite off its like turinging the key on and off,,,and the few time i was able to make it idle was after playing with a bunch of things and the idle was high and low and surging and not surging its all over the place

check if your injectors are fireing i would check the trasistor that is on the fire wall
or your fuelpump relay

 

[TonyM2487]

Which trasistor are you talking about and what should i be looking for around the termanls,,and the fuel pump has the rewire kit on it

 

[talon187]

the isc could be bad mine did that when i changed back to a stock intake manifold. i put a new isc on and problem sloved. hes talking about the transistor pack on the fire wall 4 wires come out and go to the plug kind like the maf plug. I wouldnt worry about that yet. I would make sure your injectors are all firing first. if you can get it to run even if it surges. unplug one injector at a time and see what happens

 

[TonyM2487]

Ok I will deffently check the injectors tomorrow,,,if its not that what else do you think i should check

 

[talon187]

have you done a boost leak test? did you check the ecus?

 

[TonyM2487]

No i have not done a boost leak test,,havent made the tester yet. How should i check the ecus

 

[talon187]

Ok do a boost leak test first. it honnestly sounds like thats your issue. my guess is that its a big one. to check the ecus take the cover off and look at the caps and the board. when you do a boost leak test use some soapy water. check the intake manifold and lower injectors seals along with the throttle body and intercooler piping

 

[TonyM2487]

ok i will try that as well thank you

 

[TonyM2487]

Ok so i messed with the car for a while today and was not able to make any progress with it. I really have no idea what is going on with this car i have never had these problems b4,,,i was able to get the car to idle a little today but it wudnt rev pass 2 grand and the idle was all over the place

 

[talon187]

have you done what we've told you? boost leak test? im not going to give you anymore help untill you've done one this sounds like a big boost leak and as far going past 2k it could be a few things but im not giving anymore input untill a boost leak has ben done

 

[wises4057]

dido on the boost leak test. I had an issue like this on my 1g awd...it ended up being an intake manifold gasket going out, 2 of the 4 holes on the gasket had blown out which caused it to start and die, and would keep running if I floored it.