A week ago my 96 caravan 2.4L died while driving. Like someone turned the engine off. I tried to restart but it only turns over.
I did some tests and research and I bought a new ignition coil, spark plugs and wires, and cam and crank sensors. The new sensors have the flat pin, but my old ones have the round pin and they wont fit, so im not sure if the sensors are the problem. I dont even know where to get the sensors with round pins.
timing belt is fine, all fuses and relays are good. I put my fingers over the ASD and fuel pump relay and I can feel them click once when key goes in run position.

I put the key on, ding ding sound thingy, have little less than half a tank of gas, hears fuel pump buzz for couple of seconds, then move key to start position starter engages turns engine over, can tell there's compression, but that's it. No attempt for any combustion.

Took the spark plug out and im getting gas, so the injectors are firing, but plug is cold and tried to see if there's spark when turning engine over and nothing.

Tried this before I put the new parts on and after. Still the same. I can't check engine codes by the key dance, because my cluster went out and I purchased one without cruise control by mistake, so my engine light comes on as the cruise light :| Been like that for 4 years, so I know it's not whats causing no start.
I ordered a diagnostic dongle and have torque pro scanner on my phone to see any codes. Should be in friday.

So all in all im getting compression, fuel, and I just need spark. Something is preventing the spark plugs from firing.

 

I was taking a look under the van and I found some wiring that goes to the crank sensor, oil sensor, O2 sensor etc goes to a bundle and the driveshaft of the van rubs on it, doesn't look worn through, but looks like it melted.
If the OBDII reader cant find anything, I'll have to go back under there and remove that section of harness to test for any open points. I'd rather remove it, hard to work under there with so much in the way.

 

Im not getting any codes, says there is none, but im still not getting any spark.
O2 sensors are within range, something knows how many RPMs the engine turns when starting. About 175RPM. So cam and or crank sensor should be good?

 

I did the ignition coil pulse test with a home made 12v test light and I get pulses on the blue wire, 12 volts on the center green/orange wire (tested with volt meter while cranking) and the LED light stays on for the other grey pulse wire. Even with the ignition off.

I removed the PCM and found continuity on pin 10 (ground) and pin 11 (ignition pulse) , but not any other pin.

This would indicate a bad PCM?

 

Did you find any damaged parts of the wiring harness?

 

Did you inspect the timing belt?

 

Nope all good.

I sure did. I put cylinder 1 at TDC and the timing notches are 1/2 notch difference like it is in the manual.


I did the 12 LED test light test to see if im getting switching signals. The blue wire my LED flashes while the engine is turning, I try the grey wire and my LED stays on the whole time. Even with the key off and out.

The green/orange wire I do get 12v when cranking.

I removed the PCM and tested where the grey wire would go and my multimeter has continuity on that pin and the other three ground pins.
Pin #11 coil #1 driver, #10 ground, #50 ground, and #43 sensor ground.

With the PCM attached and the two 40 pin connectors and put one lead of the meter on the #1 coil driver wire, put it on ohms, and place the other wire on any ground, engine, frame, etc, I pick up continuity. #2 I pick up nothing like I should.

So it's the PCM thats the problem?

 

Ordered a rebuilt PCM, they transferred the VIN, mileage, and have a lifetime warrenty once I send the old one back. Now I have a perfectly working van. I never seen it run this good. Idles so smooth and used to vibrate and shudder when decelerating, but not anymore. Also used to take a while to start. I just turn the key to start for a second and starts right up.
Took it for a long drive and no major issues. Had a small oil leak around the new crank sensor, but I removed, cleaned and added gasket sealant.

I replaced the coil, spark plugs and wires, cam and crank sensor with new harness plugs, replaced broken wiring covers, and the main problem the PCM.

 

What company reflashed a CPU for you?

 

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