GP1138 Posted May 24, 2009 Report Share Posted May 24, 2009 I'm seriously starting to suspect the '93 is out of time, it starts up just fine but it acts like it's missing on two cylinders. I've replaced coilpacks and plugs, wires are in the right place and plugs that came out (PLATINUM AUTOLITES) were black and sooty. The odor of raw fuel is prominent after shutoff. What are some symptoms of timing being off on these motors? Quote Link to comment Share on other sites More sharing options...
ManicMechanic Posted May 24, 2009 Report Share Posted May 24, 2009 You replaced the coils, but did you replace the ICM? Quote Link to comment Share on other sites More sharing options...
GP1138 Posted May 24, 2009 Author Report Share Posted May 24, 2009 You replaced the coils, but did you replace the ICM? No, I guess I didn't figure on it being bad more than the coils... It was too much of a bitch or I would have pulled it off the '94 DOHC before it departed. Quote Link to comment Share on other sites More sharing options...
ManicMechanic Posted May 24, 2009 Report Share Posted May 24, 2009 I got a dollar that says it's a bad ICM...My '92 CS 3.1 did the same thing. Quote Link to comment Share on other sites More sharing options...
jake91 Posted May 24, 2009 Report Share Posted May 24, 2009 when the timing was off in my car it was louder, it started hard, and it shook when it hit od at below 60 Quote Link to comment Share on other sites More sharing options...
GP1138 Posted May 24, 2009 Author Report Share Posted May 24, 2009 I'll have to procure an ICM and try it... I always tell people that, but I guess I just figured the worst in this case. Quote Link to comment Share on other sites More sharing options...
White93z34 Posted May 24, 2009 Report Share Posted May 24, 2009 if all else fails run a compression check. Quote Link to comment Share on other sites More sharing options...
jman093 Posted May 24, 2009 Report Share Posted May 24, 2009 Put a vacuum gauge on it. Hook it up anywhere past the throttle body. It should have about 18 inches of vacuum at idle. It it's got close to that you're valves are opening and closing at the right time. If it's not there's a problem. When the timing belt jumped on my GTP a couple weeks ago, I put a vac gauge on it and found it was only pulling 12 inches at idle. Knew right away it was out of time (just put the new belt and tensioner on today actually). Quote Link to comment Share on other sites More sharing options...
AWeb80 Posted May 27, 2009 Report Share Posted May 27, 2009 Find out yet John? Quote Link to comment Share on other sites More sharing options...
GP1138 Posted May 27, 2009 Author Report Share Posted May 27, 2009 No, I haven't had a second to work on it the past few days. When Thursday afternoon comes along, I might have time, but I won't have an ICM. Maybe I'll see if I can rent a vacuum gauge. Quote Link to comment Share on other sites More sharing options...
GP1138 Posted May 29, 2009 Author Report Share Posted May 29, 2009 Took this out around the block again today, and it's still got a miss in the idle, manifesting in a poot-poot in the exhaust and dying at stops/no power. Today I noticed that what sounded like a possible lower engine knock when warm is actually the catalytic convertor rattling with the poot-poot of the exhaust. The only way I can describe this is it sounds exactly like a light lower-engine knock. I might put up a video. Quote Link to comment Share on other sites More sharing options...
w-bodys_are_the_best Posted May 30, 2009 Report Share Posted May 30, 2009 Sounds kind of like a clogged cat. Thats what my Z24 did, had a knocking sound and had a huge power loss. I had only straight pipe from the cat back at the time and it would also get very quiet at the same time it would lose power. If I was coasting to a stop at idle and hit a bump it would instantly get louder and had more power when I took off, but as soon as I took off it would plug back up, get quiet and lose power again. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.