1990 Chevy K2500 4x4. 1991 Vette TPI motor. Engine swap, wiring is complete. Motor runs great until above 1/3 throttle, then dies on it's face. I am using the stock truck computer, which I think does not have enough power to open up the injectors all the way. Any plug an play ECM recommendations? Or any recommendations I can do to fix my problem

 

the 90 truck ran 19lb injectors the 91 vette uses 22's, its also speed density and I believe the truck was MAF, I might be wrong on that but theECU is not tuned for that motor. Put in the 91 vette computer and harness.

 

If staying with OBDI, you must use either the 1227165 ECM (86-89 TPI), the 1227730 ECM (90-92), or 1227727 ECM (90-91 Corvette). You can not use the truck TBI ECM.

If upgrading to OBDII, I would recommend the 12200411 PCM (01-02). As OBDII, you can use either single coil and Vortec distributor (01-02 Express Van calibration) or coil per cylinder (any LS1 type calibration).

 

I have a ECM/PROM from 1990 Firebird, plugs directly into the harness. All electrical works, but will not start. Is this because of an antitheift program in the ECM?

 

If antitheft (VATS) has not been removed from the calibration, then that is absolutely a problem.

 

Is VATS in the ECM or int the PROM? How do you remove VATS from calibration?

 

VATS is in the PROM. VATS is removed with a custom calibration (Tuning Software and PROM Burner). See http://www.moates.net and http://www.tunercat.com

 

Your going to have to upgrade the fuel pump as well. If you have not done so already?? The stock tbi pump is only good for maybe 15psi and the Tpi needs at least 40psi. Just my 2c's

 

WRONG... You CAN use the TBI ECM.. I have and it runs VERY well with NO code or hardware changes. I made changes entirely in the calibration. If you really want to do it right, you can upgrade the early TBI ECM with the EBL Flash with Port Fuel Mod from Dynamicefi.com. It is a great tuning system that plugs right into your stock harness.