I just realized I been asking this question at the 3si.org forums for almost 4 years with out a single response.

I performed a motor and trans swap on my 92 stealth back in 03, ever since the tach has not worked. I been rounds with the guy who sold me the set and have never to an end.

Anywho, can someone maybe point me in a direction I haven't been and not to the dealer either :P

When the key get turned to "On" the tach needle goes to 2k and sits. when the car starts it goes to 3k and sits it does not flucuate with the motor revs. I have since bought a autometer tach to try and hook directly to the control mod and to the ecu with no luck from that either. I have found all the wires that are involved, I have swapped the control mod (under the coil pack) I have swapped the coil pack both with no luck.

I found this forum in hopes of other avenues of people who have experience with these cars.

Please help if you can, and thanks for any input you offer.

 

Are you sure you don't have a short somewhere in the wiring?

 

Not really sure, don't know how i would tell or where to start to find it. I've been thru the connections that deal with the tach.

Now that you mention it, it does sound like that might be whats happening.

 

Wiring is almost always most frustrating thing to work on. Continuity tester and few other basic tools can help in troubleshooting. Also having bad ground can cause problems
EDIT: after reading your post again i'm thinking that one way or another it's actually not getting the right signal. Something in the wiring is wrong. It's like it's hooked up to the wrong source like a battery and it reads constant value.

 

Which made me wonder if I had the correct ECU for this set up. the car runs pretty bad, it has always ran bad on me even befroe the engine swap,but now it's just worse. Luckly its been parked for the last 2 years so it'snot leaving me stranded anywhere. I found a pin out for the ECU and found the pin thats supposed to be the Tach but never ran a continuity check on it, I should probably break out the meter and make sure that is infact where everything is coming from. Is there a way to check numbers from the engine to the ECU?

Thanks so much for your responses, this is more help than I got in the last several years of posting this problem on any forum .

 

Check if you have bad ecu or it might be wrong one.
Here is a website with some part numbers:
http://johnmonnin.netfirms.com/ECUpartnumbers.html

 

Great thanks! I will check that when i get back to the shop. Not sure really on what the MD #'s stand for.

Thanks a heap!