Hey guys i recently got a misfire at idle. Ive replaced the coil pack, spark plugs, every sensor on the intake manifold, took my missing link out to see if itd change and nothing. Ive swapped out the fuel pump and everything, at this point im pretty scared. The car will start fine, slowly come down to 1000rpm, start to miss, and slowly drop in idle. fall to close to zero, and quickly raise back up like it started again. I'm lost, i cant even drive the car because itll backfire a bit under load. Help me out guys. Thanks.

compression test.

Whats going through your head? you think its timing/ head gasket? im not burning anything which leads me away from a bad head gasket, but will a compression test tell me if the timing is off

No, a compression test will not exactly tell you your timing is off. But it will tell us a general condition of your motor, Have you tested the CLT "coolant temp sensor", test it hot and cold.

Based on your symptoms, I was recently just having the same issue on my stock 420A after new coil pack, plugs, wires, clean TPS & IAC motor, new MAP I had lying around.

It was the CLT but took awhile for me to get the code. Don't know if your still running stock ECU though. Only 14 bucks for me at O'Reilly's, if it is BAD. Once I got my new CLT in, RAN PERFECT, PERFECT IDLE, till the morning after it blew the headgasket giving me rod knock all over again, blah blah. No thread jacking, sorry.

If you need the test specifications let me know.

My 0.02. Jeff.

EDIT: Awhile to get the code, meaning a few cycles of the ECU & Engine running, though not driving. Just wanted to clear that up quick.

Originally posted by 2ndGen-ElTalon
No, a compression test will not exactly tell you your timing is off. But it will tell us a general condition of your motor, Have you tested the CLT "coolant temp sensor", test it hot and cold. Based on your symptoms, I was recently just having the same issue on my stock 420A after new coil pack, plugs, wires, clean TPS & IAC motor, new MAP I had lying around. It was the CLT but took awhile for me to get the code. Don't know if your still running stock ECU though. Only 14 bucks for me at O'Reilly's, if it is BAD. Once I got my new CLT in, RAN PERFECT, PERFECT IDLE, till the morning after it blew the headgasket giving me rod knock all over again, blah blah. No thread jacking, sorry. If you need the test specifications let me know. My 0.02. Jeff. EDIT: Awhile to get the code, meaning a few cycles of the ECU & Engine running, though not driving. Just wanted to clear that up quick.

Wow probably the most informative post if seen yet haha. I'm gonna head over to the junk yard tomorrow and pull a couple of those sensors. Thanks man I'll let you guys know how it goes!

well i went to the yard, pulled every sensor but the knock sensor just cuz its in a bad spot. I replaced everything and nothing helped, until i reset the ecu. Wehn i did that, it had a poor idle, i hit the gas twice and it settled out? I went to drive, 3 good pulls, came to a stop sign and it started loping bad. How about we try to fix my obd reader? i dont know why but it wont scan.

Check your cig lighter fuse. OBD port shares same fuse.