97 No Crank, No OBDII No start,

[WaOBSPS]

Alright guys, HEre is the full story pipe in and ask, ill answer any questions, and try/test anything.
I have a 97 7.3 PSD 4spd auto,4x4, extended cab. In January I drove the truck to work, slipped and fell, was takin to the hospital and left my truck at work, My wife went to pick up the truck while i was home recovering, and the damn truck wouldnt start. I showed up a week later and attemted to start the truck no luck. gave it 3-4 days and tried again, after checking for fuel in the bowl, and trying to hook in with my 300 cheap scanner. Truck started and ran home, parked it and then it would start again.. Cheap scanner had no connection. Fuel bowl was full. After not being able to hook in with my cheap scanner I talked to Snap-on and picked up a Solus Ultra 3400 dollars later i hooked into my OBD2 port and magically my truck started and ran. 24 hours later, no start, no connection. truck hasnt run since this was near the end of February. Batteries are tested at 900 cca@ 12.6 vdc, grounds test less then .02 ohms to battery terminal. positive tests at .02 ohms to battery + tested at ECM unbolted from ECM under driver side hood connection. Solus says ecm does not excist, OBD terminals show .01 ohms tested from under dash to under hood @ pcm plug. Fuel bowl is full, mechanical lift pump is working. last time i was able to see pump pressures were at perfect levels. Had a suggestion from another ford tech to check IPR connector for circuit ground, checked based on his suggestion, found connector insulation in plug had melted, repaired insulation. New ecm ordered on warranty. I replaced the ECM a week after a bought the truck, it was sending bad signal to the IDM. New ecm installed, with identical results, third ECM ordered for good measure with identical results.

As you can tell i do have a bit of experience, When we find a solution ill be more open about my credentials.
I am open to any tests, ideas, suggestions, questions.
Thanks for time
Nick

PS any help to capture the lil gremlin can and will result in a $250 money order in your name, to your local western union....yes i am that frustrated

[WaOBSPS]

Alright, spent an hour on the phone with James from DP-tuning today double checking all of my tests, and he suspects that is could be possible that my fist ecm crashed, and the replacements were blank from the factory. Not the fuel bowl ground because the fuse isnt poping. SO, i will be shipping my Pcm to james so he can check and make sure it has a tune loaded on it, and that it is working as it should..........

and im VERY serious about that 250 dollar reward

[porkchop6209]

Not sure if your 97 is wired the same as our 01 350 7.3, but go read my post under A Quest for Knowledge and A Word of Caution and ck/swap the IDM module relay voltage/position. See if you have a bad relay.

[WaOBSPS]

Originally Posted by porkchop6209

Not sure if your 97 is wired the same as our 01 350 7.3, but go read my post under A Quest for Knowledge and A Word of Caution and ck/swap the IDM module relay voltage/position. See if you have a bad relay.

tested all relay coils, 65 ohms, and voltage being supplied is good, and grounds on the other side are good.

[porkchop6209]

Did you check the voltage on the IDM side while someone was cranking it over? That's when ours would drop out, everything tested fine while it was KOEO, but the coil dropped out under load and the voltage dropped to just over 2v. Killed the power to the IDM and it wouldn't energige the solenoids.

[WaOBSPS]

Originally Posted by porkchop6209

Did you check the voltage on the IDM side while someone was cranking it over? That's when ours would drop out, everything tested fine while it was KOEO, but the coil dropped out under load and the voltage dropped to just over 2v. Killed the power to the IDM and it wouldn't energige the solenoids.

No i hadnt checked power to the IDM, because of the fact that koeo/not cranking, i still have no OBD coms. But i WILL check that thursday morning. that will be the next time i will have anytime off of work to check

[porkchop6209]

So is it not cranking over at all in the start position? Also, have you checked the alternator when it was running to make sure the diodes weren't failing and it was running too much current through the electrical system? That can roast a PCM, sometimes instantaneously. If you can, pull the alt. and take it somewhere that can load test it before you throw the juice to the system when you get the PCM back, just to rule it out, unless you've already done that. I have seen it happen on gas models before.

[WaOBSPS]

Originally Posted by porkchop6209

So is it not cranking over at all in the start position? Also, have you checked the alternator when it was running to make sure the diodes weren't failing and it was running too much current through the electrical system? That can roast a PCM, sometimes instantaneously. If you can, pull the alt. and take it somewhere that can load test it before you throw the juice to the system when you get the PCM back, just to rule it out, unless you've already done that. I have seen it happen on gas models before.

Yes it cranks with the key, full charging system test with midtronics tester prior to ecm failure, thought that the batteries were going, so i checked it out when the truck was running, voltage/amps were good.

[porkchop6209]

Well, obviously from these, and other posts I've read, this isn't your first rodeo. You know your way around under the hood, sounds like you've covered your bases. Have you gotten the PCM back yet? Check/swap the IDM relay just to see. Mine bench tested fine, also. Since changing it we haven't had a bit of trouble, starts soon as I turn it over, even cold. Have you pulled the harnesses apart to see if there is any obvious wear spots? I hate when they break down inside the insulation, you can still get just enough continuity to throw the meter, yet not carry current across the circuit. Do you have a break-out box that you can test in-stream voltages/grounds?

[WaOBSPS]

Originally Posted by porkchop6209

Well, obviously from these, and other posts I've read, this isn't your first rodeo. You know your way around under the hood, sounds like you've covered your bases. Have you gotten the PCM back yet? Check/swap the IDM relay just to see. Mine bench tested fine, also. Since changing it we haven't had a bit of trouble, starts soon as I turn it over, even cold. Have you pulled the harnesses apart to see if there is any obvious wear spots? I hate when they break down inside the insulation, you can still get just enough continuity to throw the meter, yet not carry current across the circuit. Do you have a break-out box that you can test in-stream voltages/grounds?

i havent had a chance to get the PCM out yet, ran into a problem with the wifes kia,and a customers 96 F350/horse trailer. ive got to get those two out of my hair. I have been dreading pulling the harness down and out, But i am considering doing that and now that youve pointed me in that direction, i suppose ill proceed. Before i pull it out too far, im gonna check signal out of the ECM/to the IDM relay, regretfully no break out box, so ill have to do it all the hard way

its the only thing i hate about powerstrokes that Power part.....