So basically Im getting codes 12 and 14 every time i drive the truck. Sometimes it will drive fine for 50 miles with no issue. Sometimes CEL light flashes/ truck stalls/ transmission hucks and bucks.
The truck always takes an extended amount of time to start. Cold, Hot, doesn't matter. Clear the codes and they come back every time after starting vehicle, even if it drove fine for the last hour.

I think it's the ECM.
I've replaced all the ignition parts (plugs, cap, rotor, dist., ignitor, coil.)
Checked wires to ECM (less than 1 ohm drop from end to end)
Installed new ECU temp sensor.
New TPS.
New Battery.
Checked and cleaned the VAFM.
Added some grounds to engine (cleaned existing grounds)
Cleaned grounds under driver side dash ( including removing paint and adding new wire o type ends)
Are there more grounds to check and clean near ECM?

What else should I check before ordering a new ECM?

Are there inline relays or switches that could be dropping ground to distributor or ignitor or coil? i checked for 12 volts + on coil and ignitor and it stays constant while cranking/running.

I'll give someone $20.00 if they point me in the direction of the cause of my hard starting and codes 12, 14 I think it's ECM because of the randomness and varying symptoms.

Lemme Know what you think, I'm dead serious about the $20.00 bounty.

Thanks in Advance

TS

 

Well, you've done everything I would do, and more. But since you're losing G or NE, and IGF every time (and the truck keeps running), it must be intermittent. Even though you've ohmed out the cables, you could have an intermittent open that only does it's dirty work when being vibrated.

I would try watching those three signals at the ECU while driving. It would be great if you could use an LED for this, but the IGF signal is so high-impedance that the load from just an LED will cause the engine to shut off. https://www.yotatech.com/forums/f116...gniter-287857/ Or, you could try just running a bypass wire from under the hood through the passenger window to the ECU. Not a long term fix, but if your code 14 goes away you know it's a wiring issue.

Good Luck!

 

I have shaken and twisted every inch of the harness under the hood across engine bay with no change or engine stall.


Is there any chance that another relay or something could be shorting out and the computer is mistaking it for code 12 and 14 (power to ECU fails for a microsecond)?

I went on a drive today and the truck ran fine (in closed loop?) until water and engine temp came up. Then it shifted in to OD and the CEL light flashed and engine stalled for 1/2 seconds a few times but kept going.

 

*****UPDATE---FIXED IT*****

Changed the ECM and truck runs fine now.

New ECM fixed several issues.

Truck starts quicker now.

Steady idle now instead of varying 200 or so RPM.

When pulling out of drive way, the first 1/8th of throttle, the truck would stumble just a little....Gone now instant throttle response when cold

No spark knock when accelerating now.

Better acceleration, faster down shifting of transmission.

Thanks to all who responded.