I have a 1991 TA 305 w/ 5 speed that is modified and has larger injectors (23#).

The car is running rich and is losing idle in open loop. If I am driving and put the trans in neutral the idle dies down till the engine kills.

What can I change in the PROM to stabilize the idle?

Will modifying the injector constant help?

Thanks.

 

Are you running off a pretty much stock setup Tune wise? Another words are you using a stock ECM with only the injector constant changed?

 

I have a 1991 TA TPI 305 w/5 speed.

It is modified with:

SLP headers and 3" exhaust
Crane Cam
SLP intake runners
SLP air foil
Crane roller rockers
TPIS big mouth intake
Accel 23# injectors
AFPR set at 47 psi
Racetronix high flow/pressure fuel pump and wiring harness
New fuel filter
All new ignition items (wires, cap, rotor, etc)
Jacob's Pro Street Ignition


I am using a SLP High Performance chip which modifies the timing and maybe the fuel.

I have not looked at the values yet, but I want to get an idea of what to modify.

I have been reading up and figure I want to at least start with the injector constant and then go to the VE tables.

But should this help the dying idle or is this a IAC problem?

 

Try putting in the stock chip and see what happens. Either that or check the TPS and IAC.

 

Will try it.

Thanks.

 

I am having a similar problem myself with a completely tuned .bin and the ECM is not coding at all. What tables should I look at in tunercat?

Mike (1bad91Z)

 

What exactly are you experiencing 1bad91z??

You have similar modifications to my car.

I am thinking that my PE tables will need to be adjusted.

 

The car is still running on the rich side and after the start and warm-up parameters, I forget how many seconds and temp it was set to, it will start to lose idle and I have to nurse the throttle to keep it running. Inj. constant is set to 25 and I also have the same .bin with 26 inj. constant and 27 inj. constant (I haven't tried the 26 or the 27 chips yet). But I figured that 25 inj constant would be a good place to start, being's I have 24lb SVO injectors set at 42 PSI.

Mike (1bad91Z)

 

Sounds very familar. Are you running an auto tranny or 5 speed. I am running a 5 speed and the car sometimes dies while out of gear at a stop. Idle just gradually dies off to nothing. But other times it is fine. Need to look into modifying idle RPM tables. Are you famailar with these tables. If so, enlighten me.

Thanks.

 

I swapped the auto for a six speed a while back (see sig.). I'm still a newbie myself at PROM tuning, so I wouldn't be the right person to ask which table to modify. But, I'm learning and if I fix it, I'll be the first to post what I have changed. And if you guys fix it first, please tell me what to change!

Mike (1bad91Z)

 

I'll be on it in the next few weeks. I will have to purchase my PROM equipment, but got to recover the $$$ from the holidays.

Will post what I learn and find out.

 

I'm not modified as much as you but was having the idle problem which led to many replacements. IAC was the last one which almost completely cured the problem.

Stanley

 

Was you car coding for the IAC? Does your SES light stay on? Or did it code and replacing the IAC fixed it? Do you have the coolant to the TB bypassed?

Mike (1bad91Z)

 

I just installed a supercharger last week.

Even at non boost conditions with most of the air being bypassed thruogh the surge tube, the car has smoothed out considerably. Even in Open Loop when the car is first started.

Guess that I am still getting more air flow than before and my mixture is less rich.

Still plan on doing some chip work once I get a wide band O2 set up.