How do I use the AE scanner to check the under valve cover wiring harness? I have no check engine light, but something is not right. I am only getting 11.8 mpg. It takes forever to warm up, but unless you let it warm up for a long time it runs like crap. New ICM, new cam sensor. I bought the AE for stuff like this, but I am having trouble learning to use it.

 

I think You can do a buzz test to check is the circuit complete to the injectors. Beyond that, you have to ohm it with a meter to see resistance on the individual inj and glow plugs. I am not the best with ae so someone else with more info can elaborate.

You did not mention the mileage but sounds like bad inj or bad oil. You can pull the v/c and check the oil discharge from the inj spouts when cold to see. I bet you have a more than 2 inj not working properly when cold.

 

Thanks for your help. I have to set this aside and find another problem. All of a sudden the truck doesn't want to go beyond 65 MPH at 2000 RPM. It sounds like it should shift, but wont. Overdrive switch works because when you turn it off the RPMs go way up. But something is not right. If this wasn't a public forum I would be writing all sorts of bad words right now! All I can say publicly is "Darn it!"

 

Allowing AE to pull codes when you first hook up may give you your first clue.

This sounds like a classic ICP issue. At wide open throttle (in gear) you should see 2800 PSI ICP with 40%IPR. If you see 2800 PSI ICP with a significantly lower IPR, your ICP is lying to the PCM (reading high). It's worth checking.

If my memory is hanging in there, I believe the buzz test (Key On, Engine Off) will tell you if you have any open connections on the UVCH... as well as which ones they are.

KOEO may help as well.

 

Sounds like a possible fuel supply issue.

 

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