Speed sensor fault!!
 

Can anyone help me. Im at a loss!!

I have a 98 sti impreza. It keeps coming up with speed sensor fault. I've changed the dash the speed senor. The speed is shown fine. it runs ok upto 4500 rpm but then it has a rev limitor, I belive this is because of the sensor fault.

Everytime we've changed something it's ok, until the ignition has been off for more than a couple of hours.

The only thing that has been done was a clutch change and they forgot to plug the sensors back in and it was run. Then later there was an electrical burning smell in the car (very strong!).

I've checked to see if there's any damp near the ECU and if there are any burn marks on any of the wires in the loom and all seems fine.

Needless to say I'm stumped and do not know where to go now apart from trying a different ECU in it.

PLEASE HELP!!

all I can confirm is that no speed input to the ecu will cause a rev limit of 4500rpm..

So you only have the one problem to solve.

Time to crawl under the car and find those sizzled wires and repair / replace as neccessary, I am pretty sure the speed output from the gearbox wires got caught against something during gearbox re install, should be a ten minute job with some insulation tape and some spare bits of wire

Engine shudder @ 4500rpm
 

Hi all,

I have the same problem with my 98 Sti ( Jap import).
When accelerating the engine will start to shidder violently once 4400 - 4500 rpm has been reached. This problem happens in all gears. I have had the carchecked by my local Subaru dealer and they told me they were getting a problem with the speed sensor when they carried out the diagnostics. So they replaced the speed sensor and the problem is still there. I took it to a mechanic who specialises in Subaru's , his first thoughts were either the speed sensor or the air flow meter. We changed the flow meter and the problem is still there. Some days the car runs perfectly well and then all of a sudden the probem kicks in. The CEL comes on when the problem is there and goes away when the problem decides to. I have noticed that when the light comes on ( whilst driving) if I clutch and let the revs drop down the CEL will go out and the problem will be gone for anything from 5 seconds to 5 days.
Its driving me crazy. Anyone any ideas what could be wrong??? Any advice would be greatly appreciated.

I recently had an erratic speedo, usually failing then returning. Once failed the CEL light would come on and the ECU would restrict my driving to below 4500 revs. I drove with it like this for 4 weeks as I didn't have the time to sort it.

So not sure if this helps but my sti v7 JDM evenrually had the speedo convertor changed following problems described above and this rectified the problem.

note it was the speedo convertor [required on all imports] not sensor.

I recently had an erratic speedo, usually failing then returning. Once failed the CEL light would come on and the ECU would restrict my driving to below 4500 revs. I drove with it like this for 4 weeks as I didn't have the time to sort it.

So not sure if this helps but my sti v7 JDM eventually had the speedo convertor changed following problems described above and this rectified the problem.

note it was the speedo convertor [required on all imports] not sensor.