93 sc won't run

i have a stock 93 sc (recently rebuilt) that for some reason will run perfect until (no known cause)the check engin light will come on and rpm drops to about 1000, the car then feels like it's running on four cylinders, and if you try to acclerate you can't go over 0 psi of boost or it will try to die. this happens intermittently when ever the car wants to. i've changed fuel filter, air filter, checked all plug wires (plugs are still pretty new, 10k ) and ran the codes (only code was 33) after a while of this the engine light will go out and the car runs perfect again???
can anybody help?
thanx

musicman said:

i have a stock 93 sc (recently rebuilt) that for some reason will run perfect until (no known cause)the check engin light will come on and rpm drops to about 1000, the car then feels like it's running on four cylinders, and if you try to acclerate you can't go over 0 psi of boost or it will try to die. this happens intermittently when ever the car wants to. i've changed fuel filter, air filter, checked all plug wires (plugs are still pretty new, 10k ) and ran the codes (only code was 33) after a while of this the engine light will go out and the car runs perfect again???
can anybody help?
thanx

Click to expand...

I have the same problem! It has happened twice in the last week or so, I checked the same stuff as you did, as well as some wiring that looked suspicious. It lasts for a couple of minutes, then fine again...maybe someone has some ideas.

Bill

Code 33=EGR sticking. Having said that my bet is DIS module. Symtoms just like on mine except on mine it wouldn't run good again until I shut it off. Then when restarted it was fine until the next time. Also, no codes were thrown. Another observation is that you can't assume your plug wires are good just by looking at them. Wires that run good normally aspirated can and do crap out under boost. I chased a problem for far too long because I assumed my low mileage, aftermarket wires were good. Wrong!!!! Whenever you experience a miss as you enter boost always the first place to look is plugs and wires no matter what kind of mileage you have on them. Good luck, John

update: i drove the car this week over 1000 miles with no prob. got back into town and its started screwing up again twice (both times i let it get below 1/4 of a tank)seemed like water in the tank or some contamination but... then after filling it up and adding heet and fuel inj. cleaner it did it again anyway. i also noticed that the tach reads 1000 even when reved up to 3000 it only reads 1500. could this be caused by the ignition comp. it kinda feels like it's off time when it starts acting up. is the timming and spark controled by the same controler?
thanx guys

Before you mentioned the tach I would have said DIS module, which still could be the problem. But with the cam sensor being pretty cheap and easy to change, I'd start there.

David