Company truck goes into limp mode.

[Suny]

Whats happening guys, I work for a fabrication company that has a fleet of rental Heavy Equipment units. So when anything in the field brakes down we have a F550 as a service truck to go fix what ever brakes down.

The truck has a boom, air compressor a whole tool box on the back aux lighting. Its a pretty descent rig to say the least. It also has a PTO to drive all the auxiliary stuff and an auxiliary engine speed controller, from Ford.

You can drive the truck no problem, but after letting it sit for a while idling or after using the engine speed controller the truck seems to loose its signal from the throttle pedal. But you can still control the engine speed with the aux engine controller. If i remember correctly. Ill have to try this tomorow.

To try and correct the problem the shop has thrown countless parts at it in hopes to correct the problem. From Throttle pedals, Crank Sensors, Cam sensors, Injector drive module. So they sent the truck to the Ford dealership in town. They said the PCM was at fault. So we went and bought a new PCM. The truck is still having the same problem.

We are lucky enough to have a simple code reader, since the truck had acted up i was able to pull a few codes.

P0603 Internal control module KAM error

P1316 Injector circuit/IDM codes detected

P1670 EF signal not detected

One thing i want to try is to unplug the auxiliary engine controller for the pto and see if the problem goes away or is still there after.

Any ideas what im looking at? I downloaded the wiring diagram for the truck on this site and have gone threw lots of the other thread in this sub forum.
This was the closest i could find to the problem im having.
http://powerstrokearmy.com/forums/showthread.php?t=1423 But i think mine is different.

Just another quick question is the truck has a long start after it has been sitting for more than a week. It seems to loose its prime. Is there a test port to check fuel pressure what should it be with key on, or during cranking?

 

[BigAlsPSD]

Ford spec for fuel pressure is 52psi all the time. There are 2 test plugs on the fuel bowl that are easily adapted to test pressure. With the P1670 you might want to check the wiring around the drivers side front shock tower or the wiring going over the DS valvecover, they are known to chafe.

 

[Suny]

Sweet thanks for the info and another in road to problems.

This morning I disconnected the aux throttle controller and the truck was running fine. After coming up a hill the truck did the same thing, the only difference this time is I still have throttle responds and a rough idle and lack of power.



I can turn the key off fire it right up again SES light goes out and the truck runs like a champ again.

EDIT: I cleared the codes re road tested the truck and code P1316 comes back is there a diag chart here that I can follow or is that part of the same harness?

There was another thread here about a guy looking to buy a truck with similar problems but he wasn't able to acquire the truck because the seller never got bwck to him over the concern.

 

[Suny]

I googled the DTC and came across this YouTube video going to get the problem to act up and try his stuff out.

http://www.youtube.com/watch?v=GHwjEfJtM_g&feature=youtube_gdata_player

 

[BigAlsPSD]

The UVCH is known to work loose causing the injectors to flake out. A 1316 code only points to the IDM having stored codes, usually a KOEO test will display the IDM codes. In your codes earlier you did not have any injector codes so I would not think the UVCH is loose.

 

[Suny]

The UVCH is known to work loose causing the injectors to flake out. A 1316 code only points to the IDM having stored codes, usually a KOEO test will display the IDM codes. In your codes earlier you did not have any injector codes so I would not think the UVCH is loose.

The shop has a temp reader, and the right (passanger)bank was running way cooler than the left. The connector was on the loose side after taking the valve cover off. So now the boss wants both sides off and check everything under the covers since its not going anywhere soon.

Ive measured the resisitance in the valve covers, and they are running at 4ohms. the Glow plugs are up to 8ohms. Dunno what its supposed to be at prolly 1ohm? Also going to check compression to while its all apart.

What do i have to do to get the codes to flash with a KOEO test?

 

[JLDickmon]

The shop has a temp reader, and the right (passanger)bank was running way cooler than the left. The connector was on the loose side after taking the valve cover off. So now the boss wants both sides off and check everything under the covers since its not going anywhere soon.

Ive measured the resisitance in the valve covers, and they are running at 4ohms. the Glow plugs are up to 8ohms. Dunno what its supposed to be at prolly 1ohm? Also going to check compression to while its all apart.

What do i have to do to get the codes to flash with a KOEO test?

OBD-II vehicles don't do this. You need a scan tool. One that reads manufacturer specific codes.

See if your Snap-On guy has an older, used one. Or, order AutoEnginuity software and cables, and grab one of those $299 laptops from Sam's Club or WalMart..

 

[Suny]

OBD-II vehicles don't do this. You need a scan tool. One that reads manufacturer specific codes.

See if your Snap-On guy has an older, used one. Or, order AutoEnginuity software and cables, and grab one of those $299 laptops from Sam's Club or WalMart..

I was thinking of doing the PC thing for a while now, since I need one for my Syclone. Although I have found a wire that rubbed threw in the harness that goes over the valve cover on the passengers side, it's a brown wire with a yellow trace on it. It goes to pin 5 on the connector above the vavle cover. Gonna check the wiring schematic when I get home tonight to see what it's for, or would you guys ve able to tell me off the top of your head. I do have another question about the engine harness there is a set of 11 wires taped together, inside that there is one bare wire (aluminum?) that goes to pin 15 what's that for? Seems a little dangerous or is this just a Fordism?

 

[Suny]

Since the valve covers where off the fireman decided to change the orings on the injectors. The truck would have a hard time starting in the morning but would run fine threw out the day. I had gotten the truck together and went for a boot with it. My only problem was getting it started. The truck had an extremely long crank and would only start after reading oil pressure in the dash. I can shut the truck off and start it again no problem the real test is going to be Monday to see how it's goof to start. If the problem is oil related is there a check valve or something else that may cause oil pressure to drop and cause a long crank?

 

[zilla68]

hpop problem maybe? before you fire it up again, check the level in the hpop and see where its at. My truck wouldn't start one time last winter, but it sat for almost 4 weeks, it was the hpop was empty, never had an issue since though.

 

[Suny]

So far the truck has yet to act up after the harness and injector repairs. Thanks firths help. Anyways I'm out to work on a D6C sitting in a raptor on my way out there.

Thanks again guys.