I went out for a drive the other day with my 96 voyager 3.3 engine which was running fine and no indication of trouble in the horizon. After leaving the car parked while shopping I tried to start it and (while cranking normal) would not fire. I first checked for spark by pulling the #6 wire out and there was none. As far as fuel I am assuming it is reaching the engine because I can smell it while attempting to start the car. Later, after havin the vehicle towed home I did some further testing. I checked connections to coil pack, cam sensor, crank sensor, PCM harness, everything had no apparent problem. Tried a new coil pack, tried different sensors from junk yard. I even tried another PCM from junk yard as well
to no avail. At times the engine seems like it wants to start firing but that's it. I am getting power to the coil pack, the ASD relay checks ok too. I am frustraded as hell. Is it possible the timing chain could have jumped a tooh or two. Will that cause the computer not to send signal to the coil pack. This engine has high kilometers 260,000kms. I know the camshaft is rotating 'cause i can see the rockers moving at the #2 cyl. Can any one help me solve this puzzle, I don't want to sucumb to the dealer or a shop.

 

I'm having the same problem (97 Caravan). I haven't figured it out yet, but I can tell you a couple other things I tried (didn't turn out to be the problem for me, but....) Are you certain the fuel pump is working? I know the last time my van did this, I could still smell fuel when I tried to start it, but the pump was not working enough. This time, I took off the fuel line at the chassis, and had someone try to start it. Last time, I got only a trickle of fuel. This time, I get a stream. If you don't get a stream, you may just need to replace the pump and filter.

 

Though I must admit I have concentraded in the whole no spark issue and overlooked inspecting the fuel aspect of the car, I can tell you that I doubt it is a fuel problem because I've tried squirting starting fluid and still it won't fire if for a moment at least. I'm starting to beleive that perhaps the PCM that a I got from the junk yard could be shot too or may be it's for a 3.0L engine. The box looks identical to mine but I took it out of a van that had no engine.

 

It has always been my experience that most timing chains will fail when the engine is being started. This is when the mechanical portion of all the rotating parts are at their highest drag. With that many miles on your engine, I would look there for sure. As Far as the computer goes, as long as it has the exact same part number stamped on it as the original, it should work correctly. Alot of the same computers are used in Vans, Truck, etc.

 

further devlopments. I did a self diagnosis (the blinking method) at first it gave me a bad cam sensor ( the one a replaced earlier from a junk yard) so I swaped it again, no more codes. Still no spark with original PCM. Reinstalled the one from junk yard and it attempted to fire with light back firing (HT wires are correctly installed, I triple checked). I noticed with junk PCM, coil for 4 and 1 cylinders is generating a weak intermittent spark (I even got zapped). Whereas with the original I get nothing. By the way, I checked TDC for #2 cylinder it seems to be right on so probably no timing issue here. I'm inclined to believe that somehow I got me a bad PCM from junk yard and my original one is the cause of all my troubles right now. Does any one care to throw in their 2 cents?

 

How about the crankshaft position sensor?? Also I have had wiring problems from the engine harness that feeds the fuel injectors, cam sensor and coil pack.

 

I disconnected the crank sensor and the Auto shut down relay kicked in, so I guess it is sending a signal to the PCM. I checked for continuity at wires to coil pack, checked ok. Injectors are being energized plus it would fire with starting fluid if it were a fuel issue.
Why do I get a weak spark to one coil only with one of the two PCM's?

 

It wouldn't necessarily fire if the timing is off from a bad crank signal and if you are only getting spark out of one coil tower then you have other issues because two coil towers are fired at the same time. It could be a bad PCM again, what are the odds though, if it the vehicle was wrecked, it had to be running at somepoint.

 

Now I know for a fact that the PCM from the Junk yard is for a 3.0 engine. I tried to find another one for 3.3 but no luck. All I was able to find was another one for a 3.0 engine, but I took it just to see if it would work. It does exactly as the other one for 3.0. It provides spark to one coil only (not just one coil tower). Where as my original PCM does nothing. So I'm thinking that the 3.0L are programed differently and thus they don't work. Because if the problem was somewhere else, then my original one would do the same as the other two, right?

 

A 3 liter PCM wont work as the 3.0 only uses one ignition coil, not a coil pack like the 3.3. I would put the original PCM back in and try a crank sensor, they are by far the most reasons for a no start.