4g61t.org

I will try it tomorrow and report back. Thanks for all your help so far.

regarding the tacho mod:

when using a 91+ ecu with a GT harness the tach goes up the muck (i am not a expert on converting JDM to USDM so i probably have years wrong)

what fixes the tach problem is

re-wiring to the later model PTR, run the PTR tach output to the ECU
keep the Tacho Interface Unit and run that directly to the dash

Problem solved.

having the same problem! But.. I might have found out something interesting.

Attached is a picture of what I rewired. I'm not sure it's correct, but it's all i could find.



I put the 94 e-prom in... same thing happened.. want to rev up then die. rev up then die back down. but the tach was working still? I thought the tach wouldn't work if i rewired the two wires. I also put the old 90 ecu in the bad one, and it started up and did the same thing and the tach worked still?

Did i rewire the wrong 2 wires? This harness doesn't have a solid green 14 wire.

The 14 wire was green with a red line on it. The 6 was green with a white line.

Not sure what I think about recent discovery. I switched the ecu to a 1.6L ecu and it revs up fine?!

I must have switched the wrong wires above. Could someone please advise. I might be getting somewhere now.

Tach works on 3 ecus though.

It's wierd because if it's the other way, like i thought it should...

Black would be 6 and blue would be 14

Blue..


Black..



What do you guys think? I tried to go by color, because that's what vfaq said, even though they are in opposite locations. I think this is the way to go.

switched the wires to the blue / black wire and things are working now. I can't really go drive it because my neighbors are a sleep and it has no exhaust. But I think the problem might be solved!

drove around the block just fine. poor neighbors. also, i'm going to try the other ecu tomorrow to confirm if it's good and is just a 91+ board. Oh ya.. My tach also works perfect on a 94 ecu.