I have an 01 caravan V6 3.3L flex fuel that is missing continuously. It gets worse when a/c is on. I have checked the wires for spark, did the compression test, and can hear injectors clicking using stethoscope.

The only engine code I have is related to large evap leak.


Thanks.

 

Was the mis happening long before the evap code was set, and is it still there as the RPMs go up? If not, then maybe fixing the evap leak will cure it, especially if the purge valve is bad. If it were mine, I would fix that leak before trying to do anything else about the mis. But then if fixing the leak doesn't help the mis, there are lots of usual suspects, and you'll need to continue (in addition to what you've already done) to go systematically to figure it out.

 

The miss started several weeks after the evap code was set. Assuming the miss is still there after the evap fix then besides what I have already checked, what would be other systematic steps to take to find the miss.

 

The first thing would be to determine for certain if the problem is fuel or spark, and then start heading down the diagnosis path for whichever one it is. But since the mis followed the evap leak code, it makes it fairly likely that's the primary or maybe even the only problem. Get the leak fixed, and when the code doesn't come back, see if that gets rid of the mis. And please also help others by posting the result

 

What was the compression reading? And do you know which cylinder that you have the misfire?

 

Don't remember the readings but they weren't low and similar on all cylinders. I did another spark check the old fashion way by pulling wires with engine running. There is no arching on some until the wire is really close to the metal but on others the arching is really strong going in circular motion. I changed wires and coil and it made no difference.