I recently tuned my truck and it has been running perfect, well yesterday I started it up, idled perfectly and took it around the block parked plugged in my ALDL cable while the truck was running, the RPM's revved up to 2K, and then dropped to about 1K, then the engine started stumbling badly, and shut off. So I disconnected the ALDL and the truck kept stumbling very badly and could not stay running. Ive tried resetting the fuses inside the cab, pulling the prom out re-seating it, swapping ECU's, proms, tried emulating from my laptop through the Ostrich, check the grounds to the ECU, now when I turn it on the RPM's stay at about 2k but if they fall under that the truck dies, I have no idea what happened, I've checked all my connectors in the engine bay, I thought the ALDL shorted something out but I swapped the ECU, I dont know what to do at this point, when the truck is idling it is in open loop so a/f wouldn't effect how the truck runs, I was thinking maybe the wide band unit I have shorted out and in effect does not let the truck run, any suggestions thanks
Truck Wont Stay Running
- Thread starter Syty84
- Start date
![Quickstop [UK]](/data/avatars/m/5/5165.jpg?1570199786){kind=avatar}
Quickstop [UK]
Combating adversyty.
Re: Truck Wont Stay Running
Codes?
Codes?
Quickstop [UK]
Combating adversyty.
Re: Truck Wont Stay Running
disconnect it from the sensor and try.
Sounds ECM related though.
disconnect it from the sensor and try.
Sounds ECM related though.
Sean Krupa
Moderator
Re: Truck Wont Stay Running
I had a similar problem recently since I came from the track a couple of days ago. The Ty was running real rich and would stumble and die while idling. Yesterday we pulled the plugs and they where rich so I swapped my old plugs which looked better. On the last plug wire which was the #1 the wire was seperated from the metal connector on the plug and the boot had a large rip in it.
Took it for a drive with a old good wire and old plugs and it was running good. Today I took it out to run some errands and after a while it was running bad again. It reminded me of a 3-bar map sensor which went bad a couple of months ago which was only 3-weeks old. I have a 3-bar sensor also used for my aftermarket boost gauge so I swapped them and everything was fine as far as the engine running back then.
So today since I decided to swap map sensors and as I removed the ECM map sensor from its bracket the weather pack connector was not even attached. It seems the clip to hold the weather pack to the map sensor was broken off allowing the connector to come loose. Put a tie wrap around it and started it up and took it for a drive and it is running back to normal.
So check your connection to the map sensor which was my problem or a bad map sensor.
I had a similar problem recently since I came from the track a couple of days ago. The Ty was running real rich and would stumble and die while idling. Yesterday we pulled the plugs and they where rich so I swapped my old plugs which looked better. On the last plug wire which was the #1 the wire was seperated from the metal connector on the plug and the boot had a large rip in it.
Took it for a drive with a old good wire and old plugs and it was running good. Today I took it out to run some errands and after a while it was running bad again. It reminded me of a 3-bar map sensor which went bad a couple of months ago which was only 3-weeks old. I have a 3-bar sensor also used for my aftermarket boost gauge so I swapped them and everything was fine as far as the engine running back then.
So today since I decided to swap map sensors and as I removed the ECM map sensor from its bracket the weather pack connector was not even attached. It seems the clip to hold the weather pack to the map sensor was broken off allowing the connector to come loose. Put a tie wrap around it and started it up and took it for a drive and it is running back to normal.
So check your connection to the map sensor which was my problem or a bad map sensor.
Last edited:
Re: Truck Wont Stay Running
Okay I will try those steps next, another issue I noticed is my PLX wide band gauge is stuck at 14.6, when I turn the truck on, and the rpm's fluctuate but the gauge does not move at all, and before the gauge would get different readings, I think something had to have shorted out because this all started from my pluggin in the ALDL cable and the truck went bezerk
Okay I will try those steps next, another issue I noticed is my PLX wide band gauge is stuck at 14.6, when I turn the truck on, and the rpm's fluctuate but the gauge does not move at all, and before the gauge would get different readings, I think something had to have shorted out because this all started from my pluggin in the ALDL cable and the truck went bezerk