Hey guys,
I have a 98 Intrigue with the 3800 series 2 engine. It has about 167k on it but it has always run great up until last weekend. We were on our way into town. I was at a stop light and when I went to pull away, the car missed a few times. When we went to leave town, after the car had sat for about an hour and a half, the car was running quite rough. The next morning my wife drove it to work (still running rough) and that afternoon it wouldn''t start. So far, I have eliminated the fuel system, the ignition module, and the coils. All cylinders are running 170-180 psi except #2 which is at 150. The timing chain is fine, I tore it down thinking that was the problem :(.

It will fire and I actually had it running for about a second the other day, but very rough. It acts like it has a major timing problem. I tried some starting fluid just to eliminate the fuel system and got a fireball out of the throttle body for my trouble.

I rented an Actron code reader and pulled these codes:
P0301 is Cylinder 1 Misfire Detected (no kidding :)
P0440 is Evaporative Emission Control System Malfunction (possible fuel cap [gas cap] loose/off)
P1665 is EVAP Vent Valve Solenoid Control Circuit (1998)

I am at a loss now. Any help anyone could give me would be much appreciated.

Thanks

if their is a cylinder firing and their is nothing wrong with the ignition system your fuel injectors could be sticking, or be faulty. they have a special tool to sense the opening and closing of the injector while its running, or maybe they need cleaned. The other thing could be a bad vacuum leak in either the lower or upper intake manifold.

You might also try changing your plug wires as they might have a pinhole that is arcing out.

This is way overdue, but I wanted to let you know what I found out.



I don''t know what was causing it to backfire, but I got it running
after doing a tune up. Then there was a lot of smoke from the exhaust
and you could smell antifreeze. Obviously the plenum was bad. So I
replaced that and the car ran great.



Here is my best guess on what happened: One or more of the sensors that
I replaced (cam, crank, & coolant temp) went bad and caused the backfire. That caused the already
weak plenum to give way. By the time I had replaced the sensors, the AF
had worked into the cylinders and caused the no start. Does that make
sense to you guys?



Thanks again for all of the help. I really appreciate it.



Lynn

cam and crank sensors work in unison, by providing internal engine component positional information to the computer. laymen''s terms, it senses where the crank and cam is when its spinning. this dictates which coil should fire, and which injector should open. thankfully they arent an expensive part to replace.


my ejumicated guess is that the backfiring weakened your seals up, and allowed the antifreeze to leak. good to hear that with all of those replaced youre up and running again!