Will a Galant VR-4 EPROM ecu work in my 91 Awd TSi?

[FotownTSI]

I purchased the Galant VR-4 ecu from Showdown Motorsports so I could replace my burnt out 91 Awd ecu. Its an EPROM from a Galant VR-4, Bill from showdown told me it was the same engine and such so it would work on my car. I connected it to my car and it definitely solved the problem. I went to drive it down the road and I encountered Idle surge for a bit which then gradually became a smoother idle. But while I was breaking at a stoplight it would kind of bog down while in gear but would be fine in neutral. I was going to change BISS and the motor on the backside of the throttle body. After I changed it I started the car and it had a rough idle not really surging but it sounded rugged and after about 5-6 seconds the car died and threw a CEL. So I replaced the old motor and tried it again, but the result was still the same, about 5-6 seconds of idle then a CEL and car dies out again. Would it have something to do with the ECU maybe being different or could I have caused a problem replacing that part? I'm not sure of the name of the motor but it's below the throttle body on the battery side. I would appreciate any help in advance. Thanks alot!

 

[the_mork]

There is no problem in using a gvr4 ecu in a 1g.

The motor on the throttle body is called either an ISC or IAC. Different names same part.

 

[jeffo]

The fuel and timing maps are very slightly different, nothing to worry about. The only real difference in the GVR-4 code is the 800 rpm idle, and the fact that the GVR-4 MAS has the lower honeycomb removed, so the ECU adds a lot more fuel at idle to compensate. If you remove the lower honeycomb in your 1G MAS it should be perfect.

 

[steve]

If you remove the lower honeycomb in your 1G MAS it should be perfect.

Or just change the software.

 

[FotownTSI]

Found the problems with the car, one of the wires on the Cam sensor connector was frayed and hardly connected. Reconnected the wire and everything was solved. Idle problem was solved by just retarding the timing some. Idles fine now. Thanks for all the advice.

 

[BobG]

I'm pretty much trying to do the same thing, but have a some questions, most of which would probably be resolved by a good pointer to information on the GVR4 box.

Could someone please clarify:

1 - Usage of R129 and R130 configuration jumpers. There seem to be different definitions (regarding Federal/CA and FWD/AWD,) between the stock units. Does that follow the PCB hardware? Or does the definition follow the E931(and E932) vs E943 Galant firmware. In other words, are the resistor to I/O port mappings different, or does the firmware use the same bits for different stuff.

Objective: Get them set correctly for Federal AWD with E931 firmware in the box I have: MD165810 91-92 GVR4 E39A E2T37378 E943 FEDERAL A-Spec/US-Spec Single Board. Eprom - 200hp

[or just ignore them and patch EPROM to force the desired settings.]

2 - There are several other components designated like this inside square boxes on the top silkscreen which would also appear to be "configuration components" to setup the board for a particular vehicle. I have no information on the following, and don't know if they matter anyway:

R132 - 1K resistor installed.
R145 - 15K resistor installed.
all other parts/jumpers appear to be set identically to the mask ROM board it originally had.

That's pretty much my concern - Hardware differences which leads to the next questions:

3 - Airflow correction after hacking MAF. I did follow the basic "el-cheapo" stage 0 procedure for cleaning/modifying the MAF, so the lower honeycomb is gone. Now if that is the way the Galant VR4 is built, should I still compensate for that when running the E931 firmware in the Galant circuit board, or does the Galant hardware do that (I'd think not, meaning do in firmware, but set me straight on that.)

4. -Are there other hardware differences for which I need to compensate? i.e.: different sensor values so the scaling isn't the same as the original T/E/L circuit board, etc.


Thanks!

92 Laser 2.0 AWD 14b turbo RS (nearly stock - 3" exhaust goes on next week!)