Hello Everyone,

Car starts rough, but after after 30 seconds or so, runs well. Because I am a beginner, I have not yet learned how to properly diagnose the problem. I could use some help. The car is a 93 sedan with 113K on it.

Start up is without question rich, as engine shakes and putt-putts and exhaust smells rich at startup rpm's. We have another 93, so I have been swapping parts without any success in isolating the problem. Once the car is warmed up, it starts up fine. However, it does have a bit of a dance: When it starts, rpm goes to 1400 rpm (I'm guessing - no tach) then heads down, then goes back up to 1100, then down, then settles at proper 800 rpm idle. This procedure goes on for about 2-3 seconds. The other 93, at startup might get to 1100 rpm initially, then drop to idle promptly. So the two are different. I hope this hasn't confused the issue, but I thought I'd mention it.

Swapped parts include: AMM, IAC (clean as a whistle)and ECU. I have cleaned the throttle body and snorkel tube and have checked for vacuum leaks using the propane method (with some cardboard blocking the radiator) at injectors, near the intake gasket, around the snorkel tube and connections at AMM, and vacuum lines, all without any noticeable difference in rpms. I have smell tested the FPR vacuum line and it smells clean. There are no codes, and all the swapped out parts work fine in the other car - and the other car starts perfectly so I know something is not right. My friend Rich believes it is leaking injector(s) that forces the engine to run overly rich at startup. I have run a tank of 93 octane and some techron fuel injection cleaner through without any noticeable difference in startup. One thing I have not swapped out is the ECT. Do you think that it could be the problem? Keep in mind that after about the first 30 seconds, the car runs fine. Gas mileage on trips averages between 25 to 27 mpg.

Today was the first time I got into the 951 ECU (to swap it - which I did) but I couldn't figure out how to undo the connector to access the pins where I could check continuity and resistance per Bentley. Do you think I should head in this direction? I would truly like to diagnose vs swap parts.

I'm kind of perplexed and could use some help if someone has some knowledge to spare.

Marty Wolfson


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93 244 185K, 93 244 112K, 93 245 116K (in California now), 99 V-70 89K