I have a '97 E150 with 60,000 miles. While waiting at a light it suddenly started to idle rough. The check engine light flashed for a few seconds, then stayed on. My mechanic checked it, found a code for cyclinder #2. Pulled everything apart, tested coil pack & injector, found no problem, so replaced plug. Put it all back together, still running rough. After driving about 30 miles, the check engine light came back on. My mechanic is recommending changing both the coil pack & injector, since it's so hard to tear it down & put it back together. Any ideas/suggestions?
[updated:LAST EDITED ON 24-Apr-02 AT 10:00 AM (EST)]I very much doubt it is the injector. If you want to check it yourself all you have to do is unplug the injector while the truck is idling rough, if the idle doesn't change it is the injecter if the idle gets worse it is not. You can also do the same with the coil on plug, unplug the electrical connector, if the idle doesn't change it is the coil. Usually when it fails it is the rubber boot losing its ability to insulate and the spark goes through the boot to the head. Good luck. I forgot to mention; is the engine only missing out at idle? Only when warm? If so it could be IAC, It controls the idle, I believe it stands for Idle Air Control.
It misses all the time, not just at idle. Seems to get worse when the engine warms up. Because it's a van, the engine is basically centered under the dash, (with about 2 inches of clearance)so to get at the coil pack & injectors you have to remove all the fuel injection stuff, etc, so you can't disconnect the coil or injector & run it. You'd have to take it apart, disconnect one of the suspects, put it back together, then take it apart again to replace the defective part, then put it back together again. The book gives you like 4 hours to replace plugs. It's cheaper to replace parts then to pay for all that labor. Last May I had a bad plug, my mechanic replaced all the plugs, and the boots, since everything was apart.
I had a miss so I changed plugs and wires and the miss got worse. Then changed coils and that did not correct the problem. I have a code checker and it was missing on #4. Turned out the original wires were the original problem but I got a bad wire from Autozone on the new ones and that was it. Changed the wire and all is good.
As a followup, my mechanic was able to swap the coil on cylinder 2 (which was the one giving us the error code) with the coil on cyl 1. Bingo! Error code was now for cyl 1. Replaced the bad coil, engine now runs great. Tested the bad coil, tests fine. He said the bench test checks the primary circuit, the problem was in the secondary induction circuit. Greek to me, but it's fixed, so I'm not complaining.