Intermittant Miss
Thread Starter
Le Mans Master
Joined: Mar 2006
Posts: 5,262
Likes: 0
From: E. Amherst NY
Intermittant Miss
The car on occasion, seems like its only running on seven cylinders. It runs real rough, and almost surges with the power.
This problem comes and goes. I had the same symptoms with it last year, and I traced it down to a bad plug wire. Problem solved, and ran fine for the rest of the year.
This year it did it yet again, and I found another bad plug wire. Needless to say, I've got a completely different set of wires on there now. Still does it on occasion though. I've checked all connections on the injectors, and think I may have found a connection problem on the 6 cylinder with the wire. I'm not getting a check engine light.
Its getting frustrating because one minute the car runs great, and the next it has a hard time getting out of its own way.
This problem comes and goes. I had the same symptoms with it last year, and I traced it down to a bad plug wire. Problem solved, and ran fine for the rest of the year.
This year it did it yet again, and I found another bad plug wire. Needless to say, I've got a completely different set of wires on there now. Still does it on occasion though. I've checked all connections on the injectors, and think I may have found a connection problem on the 6 cylinder with the wire. I'm not getting a check engine light.
Its getting frustrating because one minute the car runs great, and the next it has a hard time getting out of its own way.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Make sure your wire looms are in good condition, they keep plug wires from touching metal and causing sparks where it touches. Check your wires with an ohmeter while flexing both ends and the entire wire, they should measure close to 5000 ohms per foot. If it runs bad at night, open the hood in a dark place, defeat the underhood lights and look for sparks along each plug wire. Another thing could be happening is the ECM is screwing up. About once every 3 years my 87 runs like its on 5 cylinders and then the next time I start it its ok and stays that way for a long time. Remove the neg batt cable and unplug the ECM and replug it back in which will clean the contacts, you may have an ECM connector not making good connection.
Thread Starter
Le Mans Master
Joined: Mar 2006
Posts: 5,262
Likes: 0
From: E. Amherst NY
Just replaced the looms when I did the wires. The ones that were on there were shot, which is why it ate two wires.
Seems to be running fine after "adjusting" the connector on the #6 wire. Doesn't mean it will in the morning though. I'll give the battery thing a shot if it does it again -- can't hurt to try.
Seems to be running fine after "adjusting" the connector on the #6 wire. Doesn't mean it will in the morning though. I'll give the battery thing a shot if it does it again -- can't hurt to try.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Two days after a new set of plug wires were installed, I had a shake at idle and a bad miss. #3 plug wire was open circuit. Fortunately I saved my old wires and I drove my 87 with an old wire until my mechanic got the defective new one replaced. NEVER EVER trust anything! Just because its brand new doesn't mean its good! 
