2G Tach not working, but car idles

[kyle98gsx]

Hey, sorry if this is already been discussed but i searched for 2 days and didn't find anything.

I have a 98 Eclipse GSX with an eprom ecu and DSMchip, the car idls pretty shitty and isn't drivable. The RPM on my gauge is reading 0 all the time. I have tested the power transistors (ignition module) the way i found on here to test them, the coils are also brand new. I dont know the next step, thanks

 

[Dhan]

The car doesn't run right and you're worried about the tachometer?

You said you've checked the coil pack, but I would double check the easy stuff, which would be the connections.

Do you have the shop manual? Did it work before you installed the new coil pack? The signal goes through the ECU on 1Gs, so I'm guessing it does the same with 2Gs. Like you suggested above, your ECU may be faulty in this department.

 

[kyle98gsx]

Well when the tach was working the car ran great. I had a problem this summer with power transistors frying on me. I did a mini winter build and have gone over all the connections to make sure they're hooked up.

Could my power transistor be good but the tach output dead? I know the output to the coils are good. Is it just the PT and ecu that send the signal to my gauge??

 

[gringo72884]

Tap the plastic surrounding the gauge cluster with your knuckles (hard if you have to) and see if that works. Sometimes the rpm gauge gets stuck and all it needs is a tap to get it back to normal. Its happened to me a few times and this has worked everytime.

 

[Dhan]

^ very true. Could simply be the gauge itself, or the gauge cluster. Maybe give a looksy at the back of the gauge cluster unit.

 

[John Mark Dongon]

Did you figure it out? Mines is the same thing

 

[BLACK'98DSM]

Did you figure it out? Mines is the same thing

He is no longer an active member. Maybe try the steps they recommended, and then start a new thread if you can't figure it out.

 

[my98gsx]

Wow this is an old thread, John Mark - Check your grounds in the engine bay. My friend had this same issue recently and he found that one of the grounding cables were not reattached after we did his head gasket. Once put back on the tach worked perfectly again. If you did work within your bay double check your wiring. Worth a shot

 

[import47]

Mine is doing something similar but I can't get more than 1000 rpm at full throttle