2001 dodge ram 2500 5.9 gas. Driving the other day running fine as usual, she just died. Was on a side street around the corner from home....musta been doing 20ish. Just a engine die, so I pulled to the curb. Crank but no start. Pop the hood and see a small leak(smelled gas) where the gas hose comes into the fuel rail. Its not quick disconnect anymore. Engine entirely rebuilt in 2013, most top end is new.

So i think it had got air in the rail maybe? Tighten it up ,released schrader valve, cant eye pressure, but it was there. Could hear fuel pump, let it cycle few, still a no go. Got it home last night and all I could check was the pressure. Steady at 46 and never went down in 5 minutes. Tried starter fluid one time to see if it would pop...no go. Outta light, so on to spark today.

Today I'm kinda limited as I dont have a spark testor, and any help to turn over. Here is what I do know. Just checked 1 plug, no spark. So went to coil 12V feed. Nothing there. So I'm not bothering with the coil or cap for now.

So my next test will be ASD and CPS. Now I probably cant check the sensor working alone as I'm not sure I can read the VM and hand crank it myself. I can check power and ground. My question is with the CPS being a 5V and the coil being a 12V, how does that work with each other? Does the PCM need that 5/0V reading back from the CPS to then send it to the coil at 12V? I din't even check the varied volt reading at the coil as there is no power there.

Also about the ASD relay....I assume if my horn works, I can swap them?

I am assuming that my problem lies with either the CPS, ASD, or PCM(refurbished/trade after engine rebuild for faulty O2 sensor voltage). Does it sound like I'm on the right track?

BTW I never checked the codes, I reset the PCM but had evap codes prior. I gotta redownload my ODB code program(new phone)...so I'm sure I can find any erased codes, but I doubt it will throw codes for this situation anyway.

Thanks for any help.

 

My aligator clip wasent right even after it read right on battery check.

Coil is getting 12V(11.2 but the battery is getting a pinch slower from cranks). Battery read 12.4 before retest, but checking voltage on the coil....you got to crank it.

CPS is getting 5+V and 12+ Ground. Gotta find a wrench that can turn the crankshaft by hand. Cant check coil spark till my wife gets home so I can go get a tester.

 

Yeah, the PCM will only engage the ASD relay for about three seconds when you first turn the key on. After that, it needs to see signal from the crank sensor, or cam sensor, to turn it back on. (same for fuel pump.)

46 is a tad low, should be 49, but, if the battery is getting weak, that might explain it. Still and all, 46 pounds should be enough to run the engine. (once in closed loop, the PCM can compensate to a degree for lower fuel pressure.)

When you are picking up the spark tester, get a noid light as well. (for testing injector pulse.)

 

Never even heard of that. Cool tool, but for now I have no reason to believe its the injectors. Remans with 15K miles, never showed any signs of fuel disruptions...ruff idle. I guess if all 8 went dead that would point to the PCM I would imagine(electrical). It didn't even sniff a kick with start fluid though(only tried once....hate the ****).

The only problems since engine rebuild(12/27/2013) was the PCM, that was an O2 sensor thing that followed the old engine/exhaust to new. There is one engine issue over the last few years....and thats an occasional high idle. Its very intermittent, like 1-2x's a month tops. Sometimes you can "kick it down" others maybe a restart. Sometimes if I have to put it in drive(work), it goes normal in 5 mins or less. Otherwise 99% of the time this dog hunts. But having changed 1 PCM...its not ruled out yet.....nothing is.

So obviously I still want check the coil with spark tester(wont show with bad CPS?), but I did finish test on CPS. Stated before power and ground were good. Tested the middle wire, supposed to be 5v/0v upon turning crank. Here is how I tested. Volt meter to 20dc volt. Black to ground /red to middle wire(engine connector side on all tests). 34MM socket on crank nut. Clockwise as steady as can be. 0V never jumped. I'm assuming this test is correct? I did mess up and leave the fuel fuse in for 2 partial turns....and I heard it buzz 2 times....so I assume this is the correct way to test it? I dont know if the injectors spray on the same turn spot as the CPS/PCM send signal for spark, but it should have jumped to 5V at some point between the 2 buzzes.

That test if doing correct, should point to the crank sensor.I dont want that to be the problem....I got my fingers on both bolts, but its a tight fit. Can the Crank Sensor cause the engine to die at 20 mph ish, with no engine issues (high idle)in a while? I know it can be crank no start.....but its got me thinking ghost in the machine again.....and it was the PCM last time.

 

I did put the ASD in the horn and the Horn worked. Didnt try visa versa as I've been doing my best too keep atleast the fuel relay out.....barring that last time . I got it in the drive now....still not a great neighborhood to leave stuff open .

 

Had a similar problem. Ended up being a short where the pcm harness was rubbing against the nut holding down the aftermarket air hat. I got lucky and found it by accident

 

Noid light is to verify you are getting injector pulse. It doesn't test if the injectors are actually flowing fuel.

 

Well I pulled the codes with the key before I went out today. 1388(ASD) and 1282(FI) but both those were out at one time or another. Not sure I cranked it or had key on with the ASD out though, I dont think I did.

Got the spark testor and nothing out the coil. But my readings from the CPS said it was dead. It did have juice and ground, just not 5V back to the PCM. So I changed it out. It did appear it was rubbing the flywheel a pinch. Maybe I just like rubbing my arms raw? Thats a stupid place.

I'm downloading my code reader again as I got the battery charging and resetting the PCM again. Hopefully my reader can pull old stored codes. But it does appear to make sense that its a asd circut to ground, or the damn PCM again. One would believe that to run 100% to complete shutoff in a second, it would not be a failing sensor or fuel pressure. It "should" have to be a wire short to ground or PCM.

Ill start checking the harness, then see if I can pull some old codes.....or get new ones.

Thanks for the help guys....2nd time I've dealt with ghosts...probably gonna be my 3rd PCM LOL. I think its got a warranty though.

 

If the CPS is dead, you won't get any spark. And yeah, I really dislike the location.....

 

I think I got her fingered out. I forgot to tell you guys I checked the "pulse" wire to the coil last night...momma helped and I can see in the dark great. No pulse on the test light. Thats why I changed the CPS(besides no 5v/0v on handcrank).

After shredding my arm and no fire I'm thinking "great, throw money at it you fool". God I miss my 78-79 F250's and my CJ7's. BTW that took me almost 3 hours to change, out in 20-30, the rest cussing under my breath to get the bolts back in without dropping 100 more x's.

Then I get my kid back...today I had wheels , dropped momma off. I have "pulse" at the coil, and still 12V power, but no spark. So I go get a coil and baddabing.

Didn't run right at first, havent taken it out yet, gonna change oil first, but it seems OK. Idle a bit high at 700ish, but ok.

So I ASSUME that the PCM needs read the pulse from the CPS to send to the coil as a pulse? Or the coil wont "spark" even with 12V solid provided?

That makes me wonder where the "pulse" is for the injectors? That noid light is on my list of next thing. Is it the cam sensor(rotor)? One would imagine that would be spark only, but something has to "pulse" the injectors. Its the only "sensor" that makes sense . See what I did there LOL.

In the end I believe 2 parts failed me at "close" times. I'm just trying to learn a bit more on the electrical side of things......even though I hate it. You guys rock.