Getting sick of this car.

I've been a technician for a 20 years, and i've had only one car honestly beat me...up to now.

Car is a 1999 Dodge Stratus, 2.0 L with manual transmission. Engine had spun a bearing so we rebuilt it. Had crankshaft ground and connecting rods squared up. New .010 over conn rod bearings and standard rings, main journals were polished with new bearings. Pistons weren't replaced, customer couldn't afford that much but they got new rings. Probably could've used pistons...they slap something fierce but compression is good and all.

Car ran great for a couple of weeks and was on a long distance trip when it died. Took a trailer and picked it up...no spark. Ok, so the usual tests. Crank sensor tested OK. Cam sensor wasn't working, along with P0340 code. Ah, simple. Replaced cam sensor and still nothing. Did signal check on cam sensor and i'm getting 5V spikes on the signal wire. Checked crank sensor wire too, 5v spikes there too (checked both while cranking by hand; easy to see the 0 to 5V switches that way). Checked all wires back to PCM; continuity ok. Swapped ASD relay, even though it seems to be kicking on. Have voltage to coil pack center pin while cranking and fuel pump switches on, but no grounding on outside pins of coil connector unless I disconnect the cam sensor. If I do that, it fires but it seems late. It pops out the exhaust. Once I plug in the (new) cam sensor, I lose the ground switching and spark along with it. I've tried a different PCM also...same results. When the cam sensor is disconnected, I can put an LED test light on battery positive and the coil grounds (back probing outside pins on connector, plugged into coil) I get constant and consistent switching. Once the cam sensor is plugged back in, the LED goes dark while cranking.

Anyone know where my next guess should go?

 

Got in touch with a relative and went over it with him. He was giving me the same steps I had been trying, right down to replacing the PCM. Then he said one thing about the cam sprocket pin and it hit me smack in the back of my head. I had taken the belt cover off to check the timing (which was dead ***** on still) and the pin. I completely spaced removing the cam bolt to look over the pin and put everything back together. At least that made taking it back apart easier. I only used about 30 ft. lbs of pressure to break the cam sprocket bolt...way short of the 85 ft. lbs. it should have been. I know we put it on tightly during the rebuild, my girl was asking how i was going to keep the cam from moving when we torqued it down. Maybe I didn't get enough on it, or it slipped or something, but the pin was snapped off. The cam gear spun as soon as I got the bolt/belt loose.

Not wanting to take the head off to get the cam back out, and with no way to drill out the broken part of the pin, we drilled a hole in the cam, radial to the centerline, 5/32" ...same size as the pin. Put the pin in the hole and a small tack weld to hold it there. Since the cam sprocket has a slot rather than a hole, having the pin sticking out at 90 degrees doesn't hurt. If the pin goes too far into the cam though, it gets in the way of getting the bolt in it. Slipped on the cam gear over the pin and torqued the bolt (with locktite) to several mile tons with a breaker bar. The pin is just for locating, shouldn't get any shear on it anyway. Got everything back together and it starts right up. Runs great again.

Stupid problem, and sort of a redneck fix, but it will work from now on. Just in case anyone else has this problem...