93 corolla engine check light

I recently changed my cap and rotor on my 1993 toyota corolla with engine 7A-FE. The reason for changing was just because the previous parts had about 50,000 miles on it.It ran fine.After installing the new parts, the check engine light would intermittently come on and at the same or different times the engine would studder but wouldn't die. I put the old cap and rotor on and it would run fine. I put the new cap and rotor again and it would have the same problems mentioned above. I then disconnected the battery for 30 minutes then reconnected to see if I could clear the ECU and fix the problems but that didn't work.Has anyone seen these this problem before?:banghead:

I recently changed my cap and rotor on my 1993 toyota corolla with engine 7A-FE. The reason for changing was just because the previous parts had about 50,000 miles on it.It ran fine.After installing the new parts, the check engine light would intermittently come on and at the same or different times the engine would studder but wouldn't die. I put the old cap and rotor on and it would run fine. I put the new cap and rotor again and it would have the same problems mentioned above. I then disconnected the battery for 30 minutes then reconnected to see if I could clear the ECU and fix the problems but that didn't work.Has anyone seen these this problem before?:banghead:

This a classic case of "If it ain't broke, don't fix it".

Are you certain the cap and rotor are the correct ones?

Thank You roadrunner 2 for the quick reply. I double checked the part numbers and they're the correct parts and I forgot to mention they are genuine oem toyota parts. I think the next thing I'll try is to test one part at a time to isolate which part is causing the problems. If anyone has other suggestions they're greatly appreciated.:banghead:

Thank You roadrunner 2 for the quick reply. I double checked the part numbers and they're the correct parts and I forgot to mention they are genuine oem toyota parts. I think the next thing I'll try is to test one part at a time to isolate which part is causing the problems. If anyone has other suggestions they're greatly appreciated.:banghead:

Have you noticed a corrosion build up on the rotor contacts? (In the cap)

Ant noticeable misfiring when damp or wet out?

Replacing the parts with the old parts ...one at a time is the way to go. One or both of your new parts is defective if it runs well with the old parts.
Good luck.

I think the problem is the rotor. I installed the old rotor with the new cap and the car seems to be running fine. I'm going to take the new rotor back to the parts department to verify it is the right part. It matches the old part in every dimension except the arm portion is about 1mm higher than the old one (sticks out into cap about 1mm more). Thanks again for the input!!! I'll keep you guys updated.:)

I found out the problem with the rotor. When I purchased the rotor, the parts salesman gave me a rotor for the 1600cc engine instead of the 1800cc engine event though I told him the later one. Thank you for your support!