i have a strange problem. i have the car listed above with CIS injection that i bought and have been working on trying to get it running. i replaced cap, rotor, plug wires, spark plug fuel filter, air filter etc. after fixing a few vacuum leaks it runs pretty decent for the most part except for one thing, and that is it has a misfire issue at idle. i double checked my firing order and that was correct, checked and set my timing as my Bently manual instructed, which helped a little bit. did a compression test and it had good compression across all cylinders, but it is still misfiring at idle. the strange thing is that when you pull the plug wire from cylinder one the idle speed increases a few hundred rpm's. same with cylinder four. idle increases when plug wire is pulled. cylinders two and three idle will drop when wires are pulled one by one of course. after scratching my head i decided to have a professional look at it. after waiting a few days i get a call from the mechanic and he tells me he is stumped. same issue. the mechanic went through everything: valve adjustment, leak down test compression test, tested spay patterns at the injectors, timing ect., and everything checked out good he says. so now we are both stumped he said could possible a valve issue? what could cause a misfire at idle but idle increases when cylinder is unplugged?
Apr 17, 2018 at 5:31 PM
