Need help - code 24 is driving me nuts!

[toadson]

Im having a problem with my Fiero that I cant seem to solve, and htis seems like the place that could help me the most. During the winter my uncle gave me his 90 Lumina with a 3.1 engine. I have an 86 Fiero that came with a miserable duke, so I swapped in the 3.1 in its place. I wired everything up using the Luminas 1227727 ECM and it runs. The one problem I had was that my Fiero was a manual, whereas the Lumina ECM was looking for an automatic. I had the chip burned so that it would stop looking for a torque converter, thinking it would cure my problems I was having. I was wrong. Before the tune, my car would idle up and down constantly, but was driveable. After the tune it quit, BUT it still acts very screwy. i didnt have the VSS hooked up at the time, and he person I had tune my chip said it needed to be hooked up. I went ahead and hooked up the Fiero VSS to the Lumina ECM, and while it did help, it has not cured my problem. The car drives fine when it is moving, but you come to a stop for a minute and it revs up to 2200 rpms and throws code 24. It is driving me nuts, because the car wont act up until you drive it for a while. It can idle in the driveway for 10 minutes before it will do it after cold start. Sorry for such a long story, but I am so lost as to why my ECM is not seeing a VSS signal. Please help! Thanks!

[sharkey]

id hook a scanner up to it (or get an aldl cable and use a laptop with some software) and see if it is actualy picking up the vss signal.

i know the porblem i ran into on a cavalier is 86-88 they ran the vss signal through the gauge cluster first, were the speed buffer is located, then it sends an ac square wave signal (1 wire) to the ecm. 89+ has the vss wiring run through the ecm first, then to the cluster on 1 wire.

now im not sure how the fiero has it. is there a vss buffer in the cluster??? is there one in the dash??? if the fiero is like the 86-88 cavalier, you need both wires from the vss feed the buffer for the speedo to work, but you would also need both wires hooked to the lumina ecm. if you were to wire both up in parrellel, it would likley read wrong as your splitting the signal up.