2G 95 EPROM ECU wont start in 97 Spyder GST

[Fmstrat]

I've got a 97 Spyder GST (manual). I'm about to do an injector and dsmchip upgrade, so I got an EPROM ECU from a 95 talon AWD (automatic) off partstrader. I wanted to test the ECU out to ensure it works properly before I socket the EPROM.

Swapped my ECU for the 95 ECU, and the car won't crank. It made a wierd "pop" sound the first time, so I was worried, but I tried again and it just hesitates. I think the pop might have just been backfire and I wasn't paying attention. Anyways, I swap back to my 97 ECU and she fires up and drives fine again.

Any ideas why the 95 wouldn't work? I opened it up, and all the caps look good.

 

[Fmstrat]

So a friend had a theory about this. We know that automatic vs manual and AWD vs FWD doesn't matter once you chip the ECU, but does it matter when using it in stock form? I.E. is the automatic ECU trying to control a transmission that isn't there?

 

[cuong1106]

swap the spark plug wires around. from 1 to 4 and 2 to 3. switch the two outside wires around and switch the two inside wires around it should fire right up.

 

[Fmstrat]

Really?? That just sounds.. odd. Why were they reversed for this ECU?

 

[Mitsumanny]

Firing order is reversed on the 95 eprom and the 97 ecu's. I had that problem when i installed a 95 ecu for the dsm chip. try it out.

 

[tsunari]

swap the spark plug wires around. from 1 to 4 and 2 to 3. switch the two outside wires around and switch the two inside wires around it should fire right up.

I agree . . . - give it a try

 

[Hummer]

So a friend had a theory about this. We know that automatic vs manual and AWD vs FWD doesn't matter once you chip the ECU, but does it matter when using it in stock form? I.E. is the automatic ECU trying to control a transmission that isn't there?

AT has its own computer(TCM)! It matters only when using a 1G AT ECU in a 1G MT car as the 1G AT ECU is mapped for 390cc injectors. 95 AT ECU will work find in a 97 MT car, just switch the plug wires. Do your home work?


Bob

 

[lowridin2g]

my stage 3 chip is on its way from jeff. i also got a 95 ecu from him. he did the cas inversion for me so there will be no rewiring the injector's

 

[dave99gst]

"The '95-'96 style Cam Angle Sensor (CAS) sends out a signal that's electrically "inverted" from other DSM cam sensors (1G or '97+ style). When you put a '95 ECU into a car with a non-95 CAS, the ECU ends up swapping the firing order of the injectors"

"We can't control spark firing order in the EPROM at crank time. So even with CAS inversion, you still have to swap plug wire 1 with 2 and 3 with 4"

Quote from dsmlink.com
http://dsmlink.com/faq.html#cas

 

[lowridin2g]

"We can't control spark firing order in the EPROM at crank time. So even with CAS inversion, you still have to swap plug wire 1 with 2 and 3 with 4"

ahh, no kidding. its a good thing i got this cleared up before i installed the ecu and chip and then jumped the gun cursing and kicking and punching cause my new ecu and chip doesnt work

 

[Fmstrat]

OK, makes sense now. As for "doing my homework," that's what I'm doing now. With 30 billion posts out there, its hard to find exactly what you're looking for sometimes. Sorry if this has been asked before and I missed it.

Now, I understand all of the above, but if the CAS has to be inverted, and I'm using a stock 95 ECU, would that mean I only need to swap plug wires, or do something with the injectors (harness) as well?

dave99 - Found that quote on dsmlink's site. From the rest of it: "In most cases, this produces very little noticeable difference in drive quality. But we offer the option to invert the CAS signal anyway just in case." It appears as if the answer to my above question is "no".


Thanks for the help everyone. I'll swap the wires and see what happens.

 

[PaleDSM]

Without swapping the injectors as well some people get constant random misfire codes thrown. Most people swap them for better drivability.

 

[Fmstrat]

OK, so is it just as simple as swapping the plugs on the injectors to match up with the spark plug wires?

 

[tt281gt]

OK, so is it just as simple as swapping the plugs on the injectors to match up with the spark plug wires?

BUMP

 

[GST98BIG16G]

How about COP setup?

 

[robert3212]

OK, so is it just as simple as swapping the plugs on the injectors to match up with the spark plug wires?

Ive only swapped my spark plug wires and im having some drivability issues. Is this the fix?