QuestionProblem was very subtle before i had to get inspection in Sept. CEL came on and ECU throwing codes for EGR valve solenoid, and knock sensor. Had a local shop replace the EGR sol. and transducer to the tune of $450, they wanted $500 for the Knock sensor but i declined because it doesn't trip the CEL after throwing a code. Got inspection cleared.
Blew a serpentine belt and had to limp to a parts house for replacement. After a week it really started hesitating badly after driving home from work one day and i parked it. Error was for Knock Snsr and Camshaft Pos. Sensor. Distributor had oil in it so i replaced with one from Autozone $250, Nissan wanted $600 for remaned. Checked timing and it kept advancing erraticly by 10deg at idle, but got it to 22deg BTD. No improvement, still hesitated and ran rough on acceleration and cruise in 4th/5th when warmed up driving around the block. Heavy acceleration would muscle through it and take off but no improvement really.
So next day changed the Knock sensor, it had large crack down the middle, maybe overtightened. Pain to get to,but no improvement.
Checked error codes again after a drive around the block. Forgot to clear codes before, and got Knock sensor, Camshaft Pos Snsr error, and also IAC/AAC error. Cleared errors and was goin to start car for another test drive and let it run, but it wouldnt start.
Now no spark at ign wires, cap to coil wire, and coil. Checked coil and 12volts at coil harness. Meter read funny, so i replaced coil the next day. Got new meter and old coil resistance is good and 12volts at coil harness. Harness wires look exposed but not broken, and continuity to the Ign module harness is good. Ign Switch fuse is ok and voltage reads 12v. Ign transistor module checks ok. Still not sure if the ECU Relay is closing properley but sounds like it, and ECU is getting 12volts, and i can check error codes so i assume its getting power and working.
After getting nothing i tried again today, and it started up and ran for 2 mins before quitting and wont start again. Now the only code I get is for Camshaft Pos Sensor. Then the sensor harness disentigrated like an oatmeal cookie after i cleaned it with what was supposed to be plastic safe electronics cleaner. Harness must be getting too old. Maybe the Ign resistor is bad? I dont want to change the Distributor again if i can't get spark from the coil. And could this whole rough hesitation be caused by something in the ignition sys before the Distributor?
Sorry for the long post, fix one thing and another breaks. Im getting on my last nerve with this car. Any suggestions other than gasoline and a match?
AnswerBen,
You have replaced all the usual suspects. But, when you said the harness was coming apart that is a good indication of where to look. Not too often a Nissan harness and connectors disintegrate. I would start at the engine and remove the cover to the harness and check each wire until you find your open wire and you might even find one or two that are shorted together. I had a Mustang that was darn near new and had to get a razor knife and take the tape off the harness until I found the short. It turned out to be a factory defect and it took a day to find. It is rewarding once you find the problem...
