Need some ideas on a conversion truck

J.Keith

J.Keith

Pro Diesel Tech
Joined
Feb 14, 2007
Messages
708
05 CR in a superduty

Engine cranks, talks to the DRBIII, been through the wiring backwards and forwards and it still won't fire

DRB shows 21k + psi of RP while cranking, hardline gauge confirms this.
ECM was treated to a Recovery File (Thanks again Bob!) Still no go
The most prominent problem that I can see is when the engine is being cranked the final fuel state goes from "Engine off " to " Shutdown" Why?

Only code that I have thats not related to the motor being in the Ford is a J1850 Short to Ground. Can't find it yet.


Thanks guys!

Jeremy
 
21,000 is way too much rail psi while cranking, it should be around 3-4k. usually that kind of pressure at crank will blow the solenoids off the injector bodies, but then pressure would drop under 500.
 
Yup. Thats the first problem I noticed too. WAAAYYYY to much rail pressure while cranking. But that much pressure should result in white smoke out of the tail pipe. Un burnt fuel and lots of it. Almost sounds like exactly what you would see if cranking a truck with the FCA unhooked.
 
SPEEDSHIFT said:
Have you tried changing the FCA? Make sure the wiring is good to it?
Click to expand...

If that is good check the bajo bolt/check valve in the back of the head. Make sure it is not clogged up, or just unhook it and see if cranking rp changes.
 
Swapped in a brand new FCA no change. Cranked it with the fuel return unhooked and have plenty of return. Checked and rechecked the wiring, monitered the voltage with a labscope. All is within spec. Just have STUPID high RP and the Final Fuel stat is wrong
 
Got it! There's 1 wire to the ECM that HAS to be hot while cranking and it wasn't. Found it, fixed it and it runs! Thanks for the ideas!
 
You must log in or register to reply here.
Back
Top