I helped a friens put in a gsr motor in his 94 eg. We put it in and the wire harness was messed up, it wouldnt rev past 3k. at the time the tach was working. now we swaped the harness and it runs great but now the tach doesnt work. Any ideas?

 

The tach signal will come from the ECU. It would be a blue wire at the distributor, a blue wire at the ECU and a blue wire behind the cluster.

If you want to test it, get a COMPUTER SAFE test light. (Snap-On sells a nice version by SST) Probe the blue wire while the car is running, and you should see the red and green lights alternate pretty fast, increasing and decreasing with the revs.

Do you have any CEL's? Is the car itself running okay now?

 

It runs great, the check engine light is on but he told me it is just o2 sensor but he could be wrong

 

haha...damn. my **** has the same problem. my tach never came on though. i have 1 CEL for the knock sensor....not worried about it. but hey, if you figure out what the problem is, let me know......i don't think it would make a difference that i have the jdm cluster either......

 

Any other ideas?

 

try getting somebody elses cluster and see if it works?? i'm going to do that tonight....i'll let you know if it works.....i dunno

 

check to see if the blue wire on the engine harness from the dizzy to the driver shock tower has a open or something