Since I've had my car it had what appeared to be a ignition problem. When the car was warm it would jerk under a light engine load, say between 1000-2000 rpms and then would cease once rpms went up into 2500 up. Also while sitting at the light the car would idle up and surge forward like my foot was on the gas even though it wasn't.(A4) Read the book and did all kinds of tests, and finaly narrowed it down to either the optis or ignition module based on the symptons I had and what the book said, and also what I heard from other boards. Changed the optis including the cap and rotor which was kind a pricey(and plugged off the vent hole with RTV) and still had the same problem. Then I replaced the ignition module and still had the same problem.

Did some more research and stumbled upon the EGR valve and solenoid in the back of the emmisions section in the Chilton manual. The little light bulb went off, and luckily I had a friend who worked at O Reilys who let me bring back the ignition module and exchange it for a EGR valve and solenoid. Changed it out and the car runs perfect now. What made it so painful and expensive was the fact that the ECM would not through out a trouble code, so I kinda had to guess, but hey it's fixed now!

Sorry about the long story but I just wanted to share a piece of technial info that might help someone else if the're experiencing similar problems.

Moral of the whole story its not always the Optis. Mine was functional after 112,000 miles and was still tickin.

 

Glad to hear that solved your issue!!!

 

im at 117,000 and still strong. how hard was it to get to the erg valve? im thinking of blocking mine off during my long tube install.

 

It was a total pain in the ***. On the driver side the nut was very easy to get to, but the passenger side was extremely hard. I had to stick my hand behind the intake plenum with a short wrench from the passenger side because there is absolutey no room back there and wrench off the second nut. It took me a good painful 30-40 min, since I had to do it by touch. If I wasn't worried about emissoins I would just pull all that crap off and use some type of dummy system to fool the ECM into thinking it was still there, because the engine runs F'd up without it working properly.

 

my EGR had a busted diapram. never ran bad at all. got it fixed recently as a few more codes came up. AIR system and O2's.

AIR problem was 2 bad valves not allowing for the air pump to spin properly. the air probably killed off the O2 by causing the engine to run overly rich.

 

I think mine messed up becuase the ECM program for my car is not dynamic like the 94-97 mass air flow systems. Mine just works off of a set table of values that the computer looks at. I heard this makes 93's run better in the 1/4 but Im not sure since I've neither been to the track or owned a 94-97 F-body.

 

Damn it! Maybe the advice I took was all wrong. I made an EGR blockoff for the Tube and it didnt seal... I was told if I unplugged the EGRs vacuum it wouldnt have any more issues..however I seem to have the same problem as I did before!!DOH!

I think im going to hook it back up and block that hole off!

 

What was the problems you were having anyways?

 

The car was stumbling when it got warm.. at idle it would run good... ses light would kick off...but as soon as you started off partial throttle (and in closed loop) the light would kick on and it would stumble, etc.

I knew my block off didnt seal..so I was pulling unmetered air in thru the back of the intake. I just thought pulling the vac from the EGR valve would fix it for now. Guess not.

 

pulling the vac line will not fix it if its stuck open