Just rebuilt the 3.7 in my 2002 Ram. It starts and runs, but then I have to throttle it to keep it going, and it eventually dies anyway. I get codes 1388 (ASD relay), 0351 thru 0356 (coils). I swapped the ac relay in the ASD's place, but that doesn't help. I initially thought I might have fouled spark plugs from oiling the cylinder walls to put the pistons in, but that should give me a missfire code, not a coil code. I'm done messing with it for the night, but if I don't figure it out in my sleep, maybe someone here can? I'm not getting a cps code. My tach's not working either, but I believe that's related to the coil problem. If the coils are really bad, why does it start and run over and over, for a short period of time?

 

Bump.

 

Fuel delivery? Maybe the fuel pump is not producing sufficient volume.

 

Just got home and did a fuel pressure test and had perfect pressure, as well as I was mysteriously able to keep it running (although it ran rough). Swapped a good coil (according to the computer) with a bad coil, and the code moved with it. So I guess I'll replace all the coils, unless it's still really the cms, or cps. I still have no tach.

 

If it is the coils, why would they go bad just sitting there? I wasn't rough with them, and didn't drop any of them. They all had there special little spot on the bench while I was working on the engine. And they all worked fine less than a month ago before I pulled the engine.

 

Just for kicks, I took out all the coils, cleaned them with WD-40, put them back in, and got it down to 2 coil codes. Then took those two out, cleaned them and put them back in, started it up, and got a code on all but one coil. ?

 

Coils dont usually go bad and if they do they dont all go at once. Like you already suspect, you got something else going on and need to go through all the wiring. It could be multiple things

My headlights went out (HIDs) last week. I checked my fuse and it was good. Then I got to checking my relay and main harness and found there was a loose wire there. So I replaced the entire harness with a spare I had only to find out I also had a bad wire on the OEM side of the headlights where the resistors go in place.

My point is while I found one issue, there was also another causing the same problem and it took me a while to find it. Now I have everything resolved and have all my lights working.

 

Alright, still trying to figure this out. Tonight I hooked up a volt meter to one of the coil wires, and started the engine. I got continuous voltage, as well as my tach started working again, and it ran better, just acted like it was missing on one cylinder, instead of several. If this is a ground problem, exactly where is the problem occuring. I did this test on multiple cylinders with the same results.

 

Anyone?

 

I went to the dealership yesterday, and they recommended a camshaft position sensor. So I replaced that this morning. Now my tach is working again, (which I thougt it got it's signal from the cps) but I still get the coil codes. What's weird is, the tach wouldn't work for about 3 or 4 seconds, then came to life.