1. Starting while cold. The car will start, but takes about 2-3 seconds on the starter to do it. It might stutter a bit, but it will start.
2. Starting while hot. If the car has been running for quite a while and the engine is warm, it hesitates while starting back up immediately. Similar to problem 1 above, but now it's talking 3-5 seconds to start. If you let the car sit for 10 minutes or more, then it tends to start right up. But if you try an immediate restart it doesn't like it.
3. Kickback against the starter and blowback through the intake after several cold starts. If I'm working in my garage, or on the car, you start and stop it several times to move it, back it up on ramps, etc. This has only happened twice. About the third time in a row you do a cold start the engine will actually kickback against the starter. I won't call it a backfire, because there isn't a pop. But the starter will stop dead mid-crank, and sometimes some exhaust smoke will come out the intake. Again not pop, but the engine just sounds sickly. The only way I can start it after this is to treat it like a flooded engine. I give it WOT and keep on the starter, it might resist the starter once or twice but it eventually fires but you need to nurse the engine up to idle speed. Once it hits idle speed it then runs fine.
4. Off-idle hesitation. This only happens after the car has been started recently, and it can be a totally cold start or a warm start. When you try to pull out from stop and give the car throttle it behaves almost like a cold carbureted engine. The engine almost feels like it's about to die, so you push in the clutch and rev the motor, and then try it again and you take off. After that the car runs fine. Sometimes it won't do that the first time you pull out from a stop, but the second or third time. Once it has it's fit though, it doesn't do it again while the vehicle is running.
All operation above 2,000 rpm is perfectly fine. Car runs smooth, cruises smooth, and accelerates smoothly and powerfully. I actually use the car for autocross racing and on the track it has no faults at all. The timing is right at factory spec and the O2 sensor was replaced about a year ago. Fuel pressure with the ignition on (not running) and while under load is 38 psi, at idle the car is at 26 psi. Car doesn't surge or gallop.
The auto shop I took it to is going to replace the new distributor free of charge - of course start with what changed when the problems arised. And I can see timing advance or ignition causing the problems. However, this car did have these issues very rarely before the distributor so it's not like the car never did it before. The other thing that's weird is the off-idle hesitation that just "goes away" after it has it's initial fit, I don't see off hand that could be a distributor problem. I was thinking about the TPS, but supposedly they checked it and it's fine. Computer isn't throwing codes either.
So sorry, long description, but it's a weird bunch of symptoms. Any ideas? Thanks.
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Thursday, October 18th, 2007 AT 7:08 PM
