I've got a problem with my 91 V6 ECM. Seems like the fuel and ignition maps stop at 5600! Plus with all the problems I'm having trying to tune it for V6 (limited info) I'm debating weither or not I should move over to a 91 V8 ECM with a map. Has anyone tried to do this before? We got my V6 ecm to recognize the V8 eprom, but it didn't fix the 6000RPM limit. Has anyone else had this problem? ? ? After spending a couple of hours on it last saturday, we were like Plus we couldn't get the datalogger to work.

So I know this should be in the DIYEFI, but i just want to know if anyone has tried to wire one in without eprom tweakage.

 

IIRC, the v8 and v6 ecm is the same part number, its just a different prom.

 

Thats what I thought! And I thought that that wiring somewhere had a V6/V8 selector wire, but I failed to find it. I may have missed a pin or something when I did the MAF->MAP harness. I'm still trying to hunt down a GM service manual to show every wire from the ECM side so I know I got it all.

After we got the ECM to run the car with a V8 eprom, the car still didn't rev past 6k. Frustrating. The MAF ecm will go to 6200. I really want to get this motor to turn 7k. Could it be because I have an automatic? How fast can you turn a 700r4 before it blows up?

 

Wire harness layout for the v6 7730? Dude, why did you pick up the cell and call my ****? You know I got the helms manual for a 91 right? It should have it in it. If not, over on DIY-Fi or whatever, should have it.

I dont know of any "selector" wire. Because they run in batch, you only have 2 banks of injector wires on v6 and v8.

 

Dale > < Travis

Sounds like i might have something to do on Sunday then huh? I'm thinking that its a 91ecm.... thats the first year they did the MAP stuff right?

 

There is a rev-limiter in the '90 - '92 V6 ECM calibrations. Off hand can't recall the exact value but it is right above 6,000 RPM. Speed limiter too (115/112 MPH).

For MAF wiring check the sticky's on the EFI & ECM board. There is a thread started by TechSmurf. In it is a post that has that wiring.

Pin 56 on the MEMCAL (the long thing with the blue cover) defines the cylinder count. If you do decide to go with the V8 $8D mask you will definately need to make some calibration changes.

RBob.

 

What would be the best route to go? I want this thing to go into a controlled scream over 5000RPM, and I'm pretty sure I have the bottom and top end to do it. I just have to get my bigger TB mounted. I got a 64mm from a nissan I'm going to try out.

Should I try to put a V8 system to control my 6'er, or should I try to cut and hack my current maps to do what I want it to do? I read that I could lower the resolution divider to spread the map out, but would that be the best thing to do?

I'll keep this post relative to hardware, and I'll dig around the EFI board and get some answers there once I get it nailed down. Thanks Rbob!

 

With the engine changes you are making calibration changes are a given. It then comes down to how much emissions equipment remains, and whether you can swap to a vacuum controlled EGR valve. Should be able to use a vac controleld EGR as the MAF V6's did.

I say this as my recommendation would be to go with the $8D mask (the V8 TPI code). It is just better code.

Little background to get you started, and help with searches. The stock '90-'92 V6 MPFI mask is $88. The stock '90-'92 V8 TPI mask is $8D. They both run in the same ECM: the 1227730, or '7730 for short. There may be some pinout changes in the control stuff, I do know that the EGR is way different between the two (digital vs. vac, 3 wires vs. 1).

To run the $8D code on your V6, use a V6 MEMCAL and an adaptor such as Moates G1. This retains the stock knock filter, cylinder select, and limp mode calibration.

You can then put any code you want in the EPROM/Flash chip. You do need to use a V6 MEMCAL as the injector firing is based on the cylinder count. That and the knock filter is a better match.

One other thing. There is some enhanced $8D code out there. Look for super or S_AUJP code. Myself and others have added functionality and extended tables to the base $8D code.

RBob.