Need some input here. New to this site. Pulling camper home 3 weeks ago and truck shutters,starts misfiring, MIL lamp shows itself. I turned truck off and would not start up. 2000 f-350 SW 7.3, 141,000. Well I've had great service from this truck. Normal things like CPS replacement, front bearings, and water pump (replaced under warranty). Well get truck home and pull codes 1670 showed along with high EGP. Have a mechanic at ford dealership come by and decides it's probably the IDM. I buy one on e-bay(along with a new EGP tube and sensor from ford) The IDM box was a ford part and supposedley new. Put IDM on start truck it runs for 2 minutes and I shut it off to replace inner fender. Start truck again, but no luck. try again it misfires and runs terribly rough. Well I then start thinking bad connections,grounds, etc. I've checked IDM connections,PCM connections, all the grounds that effect these components(from ford cd manual). Still nothing, sometimes it would run rough then sometimes it does nothing. Start checking voltage side of IDM & PCM relays in dist. box. Try truck again and it runs fine for 20 minutes, turn truck off. Disassemble (as far as possible) and clean dist. box, truck runs for almost 2 days and then no start, just free cranking. Have ford mechanic bring breakout box and check step by step until it says (step 14 i think) disconnect harness to valve cover and start truck, well can't start truck! but code 1670 still pops up. Manual points toward PCM. Wait till start light works normal and 1670 code will always show even after repeated clearing, pops back up after just momentary cranking, and yes I'm showing rpms on tack when cranking. Thanks

 

welcome to FTE...sounds like the wire harnes from the IDM to the valve covers need to checked out...its a common problem..the wires will rub and open up..or it could be inside the VC..here is a write up on it here.
https://www.ford-trucks.com/forums/2...or-wiring.html
before you remove the calve cover..check the harnes first..they can be ohmed out but i cant find it the specs just yet....ill keep looking but im sure some one will fill ya in...

 

this would be the plug at the VC

Pin Out
G G I I C I I G G
G=Glow Plug +
I = Injector +
C= Injector Common
***The injectors fire with a 115VDC signal from the IDM do not pierce to wires to test.***
Ohm between "I" and "C" to test the injectors, should be less than 5.0 Ohms
To check glow plugs Ohm between "G" and battery ground should be between 0.1 and 2.0 Ohms

 

Welcome to FTE.

Luckily both of Ron's suggestions are free checks and one of them is probably correct. Trace the wires with your fingers to check for chaffing, then unplug the wiring harness from each valve cover and ohm the wires looking for what's posted above. If you look at the 2nd picture in Ron's link, that's what you're testing for.

 

O.K. I'll try this and let you all know.
Thanks

 

ok, I checked the wires up to the valve covers. no visible signs of rubbing,chaffing, or discoloration on wire insulation. Will be tonite or thursday before I ohm them. If it is wiring harness(uvc) shouldn't it still try to run on partial cylinders? This thing will not do anything but crank over by starter now, not even try to hit on a single cylinder.Thanks for quick responses I'm needing to get this truck going.

 

My Excursion ran on one bank, up until I was able to limp it to my moms house. After I parked it in the driveway, I decided to move it to the street, so I started it up (one bank firing) and moved it to the street. After that, it wouldn't fire up anymore.

Stewart

PS - I didn't have the P1670 DTC. I had the P1316 Injector Circ/IDM Codes Detected.

 

Stewart H, was it the injector (uvc) wiring or IDM? Thanks dsss

 

Wiring.

I needed the UVC retainer clips from Ford that act as shims, keeping the connectors locked together.

FDDTS - 7.3L UVC Harness Retainer Clips

Please understand, I was only trying to answer your question about running on partial cylinders. I was not addressing your 1670 DTC. That's why I put the PS in my last post.

Stewart

 

Stewart H, thanks for info. Kinda new to this forum. At this point any help is greatly appreciated. Looks like I might have to load this truck up and get it to a real scanner and test if injectors ohm ok. dsss