thomeygun1

i have a 91 TA...when i first turn it on it starts up and idles rough but when i give it gas its like it hits a wall and jus dies out..when initially started you can rev it to about thirty two grand before it starts to cut out but after that it wont go above twelve hundred RPM..

i believed it to be a fuel problem at first but the fuel pressure is right around 49 PSI at idle but when you open up the throttle it goes up to almost 60 PSI..

i have replaced the fuel pressure regulater with a new one..new Fuel filter...replaced the ignition control module with a new one..replaced the knock sensor with new...i used the MAP sensor, TPS, and IAC, off of my dads car that ran fine until it spun a rod bearing recently.

i dont think it would be the fuel pump bc it seems like it is getting plenty of fuel pressure..i need some help fast cus this is my DD, Thanks

irocz28boy

iTrader: (2)

305 or 350? That seems a little high for fuel pressure. You said you're using the TPS and IAC off your dad's car..did you make sure they were set correctly?

thomeygun1

it is a 350TPI..i have the fuel pressure set at 50 PSI with the switch on and when you start it the PSI drops a little..

and i know that the TPS is set corrrectly im not quite sure about how to set the IAC but i dont believe it would make that kind of difference would it?

thomeygun1

i dropped the fuel pressure down to 47 PSI adjusted the IAC it didnt work the car stil dies out at the touch of the throttle..

would a stuck injector cause this big of a problem?

XxXChrisGXxX

iTrader: (1)

IAC is the idle air control so yes it would make a difference but completely shut the car off after some gas.

i'll give you the same advice i gave someone with the same problem.

1. Weak Fuel Pressure - Check Pressure, Check Fuel Flow, Could Possibly Be A Bad Fuel Pump

2. Check/Clean Upper Plenum, Throttle Body (Making Sure To Clean Above/Below The Throttle Body Plate), And IAC.

3. Check Idle/Timing Adjustment - Use A Timing Light To Check The Ignition Timing, Check Idle With A Tachometer (Handheld Preferable Over In Car, Or Scanner)

4. Check Your Vacuum Pressure - Use A Vacuum Gauge And Go By The Specifications On Your Car

5. Check For Leaks Of Any Kind Near Or Around The Fuel Rail

6. Could Be A Intake Gasket Gone Bad

7. Pull The Fuel Pressure Regulator Vacuum Line Check For Fuel, If Fuel Pours Out Relace The Regulator

8. Check Spark Plugs - Look For Gap Bridging (Carbon Between The Electrode And Metal Tab) Could Cause Dead Cylinders

If You Decide To Pull The Intake, Check Your Injectors Make This Your Last Resort

Hopefully Something Here Will Help You

-Christopher

thomeygun1

well the pressure is right around 46PSI when running and around 48PSI when just the ignition is on..

Cleaning the throttle body was actually one of the first things i did but it didnt help...

i think i will try changing the timing a little bit tonight see if that helps....i checked for leaking fuel and there is none leaking anywhere...

The spark plugs and wires are brand new the car started acting up a week after i put them on so they are in good shape

My O2 sensor is maybe a month old could it possibly be that

Kevin91Z

iTrader: (1)

This statement leads me to believe you have a blockage in the fuel lines. Maybe in the fuel rails themselves. Perhaps a bad fuel pressure regulator?

An O2 sensor wouldnt fail in a month unless you ran leaded gas thru it, or you were so rich it was blowing black smoke out the tailpipes.

thomeygun1

its not the fpr cus i replaced that the day it started acting up.

yea i wasnt getting any black smoke...but a blockage in the fuel rails does make sense...

i might jus swap in my slp runners with the fuel rails from my dads car and hope that solves the problem cus im out of ideas

thomeygun1

i ran a test on my injectors here are the results
... 1:13.3 5:16.8
2:1.9 6:16.9
3:16.8 7:16.8
4:14.4 8:16.9 Ohms

is this my problem..would a couple of bad injectors cause my car to die at the touch of the throttle?

Kevin91Z

iTrader: (1)

That #2 with 1.9 ohms is definitely a problem. See if you can find someone with an extra or just replace the whole set.

thomeygun1

im just going to replace all the injectors with 30lb bosch injectors..

would these be ok for a while until i get my computer tuned?
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are these good injectors?

irocz28boy

iTrader: (2)

The injectors are good, yes, but 30lbs? Are you planning on heavily modding this engine? I wouldn't do anymore than 24lbs with a stock L98. They can handle plenty of power themselves.

thomeygun1

the engine will be modded some for now..

it has a cam with i believe 270/280 duration and like .460/.474 lift im not sure exactly i dont have the cam card on me right now and im also putting the sdpc base on it, slp runners, and porting the plenum..it also has 3.73 gaers and a corvette stall

afremont

The factory (multics) injectors can stop flowing when the pressure gets to right around 60PSI.

Kevin91Z

iTrader: (1)

The engine will run pig rich with 30lbs injectors and the stock chip. You dont need 30lbs until you install heads, cam, and a higher RPM intake. 24lbs are just fine but it will run slightly rich until you get the computer tuned.

thomeygun1

alright i dont think im going 30lb injectors...i think i will go with the 26lb venoms

irocz28boy

iTrader: (2)

If it's going to run a little rich with 24lb injectors, what do you think it'll do with 26lb? At least tune the computer as soon as possible when you put those injectors in.

thomeygun1

So i replaced my injectors this past weekend and it turned out to be the problem...i took your guys advice and went with 24lb injectors...that bad injector was probably stuck closed and when i gave it gas it caused the fuel pressure to shoot up to 60psi and then the injectors would quit working
Thanks for the help!