Just finished pulling my 21ft. Center console to key west and the truck ran great all the way down. As soon as I made it to the house I got a check engine light and the code was P0279. The truck started to lope. I parked and left it til a few hours later. After a bit I cranked up and it was running fine. The next day I cranked up to launch the boat and it was running fine until I got back to the house and it started to lope again. Just cranked up again and it starts fine but runs for 10 secs and then starts to lope. FICM all good volts, battery all good volts. Any way to know if I have a chaffed wire or bad injector? I live in the panhandle of Florida so a long 10+ hour drive home. I need my truck to work. Any help will be greatly appreciated!!!!

 

Measure the open coil resistance between pin 1 and 2. Then measure close coil between pins 3 and 4. It should be between .4 to .6 ohms with the engine cold.

 

Do you measure on the harness coming from the injector or on the wiring harness going to the injector?

 

Your testing the coils, so it's on the injector side.

 

If the coils test good would it then be a chafe in the harness? Seems weird it is intermittent.

 

Heat and vibration can make it intermittent. Harness is the other place to check.
Post your results.

Maybe your truck just doesn't like the Keys.

 

Will do!! Thank you for the quick response!!

 

What will it show if it's bad? Zero?

 

Checked the injector ohm's and 1+2 and 3+4 both showing zero. Bad injector?

 

Check on another known good injector to verify your meter is good. Double make sure you're on the correct pins and have good contact.

 

Here is the engine control and sensor harness in this PDF.
You can use the diagram for the injectors to find what pins
go to where.
This PDF is one of the keep in a safe place ones. Comes in handy
when tracing things.

If you need others let me know and I'll see what I can find.

Enjoy.



Sean <BR>

6.0L Tech Folder

 

Literally have same code pop up yesterday. I swapped #5&7 plugs cleared the code and waited till the light came back on. Easy way to check to see if it's the injector or the harness. In my case it's the injector that took a crap.

 

How long did it take for that code to come back up?

 

I think it would pop pretty fast.

 

Swapped the number 5 and 7 and got p0273-cylinder 5 low circuit and p0281-cylinder 7 contribution balance. I'm at a loss. Need help ASAP!!