CPS question

[69oiler]

ok so today i got a check engine light, and reduced power. the trucks starts normally. the CEL seems boost related, because i can make it go on and off by making boost (on with boost, goes off at idle or cruising)

one weird thing, even though the truck starts normally, the tach does not move for the 1-2 seconds during cranking. do you think it's a CPS issue? none of the other symptoms seem to fit CPS problems that i know of.

i have an appt at the dealer tomorrow to get it scanned.

 

[97idi]

from my experiecnces with any truck and the cps it seems to have trouble starting and it idles rough

 

[69oiler]

that's what i was thinking.

 

[howards@howard]

cps

I had one in a 98 that was intermittent ran off and on for weeks. Get the IH one on line and put it in yourself

 

[93turbo_animal]

Most CPS victims complain of cutting out not reduced power. I would look at either the IPR ICP or the MAP sensor

 

[69oiler]

it turned out to be a P0476 exhaust backpressure control valve code

in other words the wastegate was sticking. the problem went away overnight, but now i know where to look if it happens again.

i got my trans flushed while i was there too.

 

[Russ]

It's not a wastegate Rob, It's the EBPV. A wastegate dumps extra boost to the atmosphere.

 

[69oiler]

yeah my EBPV has been unplugged for a couple years and i told the tech that. he said it was the wastegate sensor or something to that effect. which would make sense, since the turbo noise changed and the CEL only came on under boost, and went off at idle or cruise.

i think the waste gate was hung open, that's the way it was acting. EBPV can't move with no power to it

 

[69oiler]

i looked it up here

http://forums.dieselpowermag.com/70...werstroke-diagnostic-trouble-codes/index.html

it's not backpressure, i misquoted. it's P0476 Exhaust Pressure Control Valve Mafunction

 

[Double-S-Diesel]

the 476 has to do with the ebv bieng unplugged and nothing else.
I would swap the cps if there were no codes.

 

[69oiler]

the 476 has to do with the ebv bieng unplugged and nothing else.
I would swap the cps if there were no codes.

then why did i lose power? and why did it wait 2 years to throw a code? as you know, my EBPV is unplugged since we did the 4" exhaust, so it couldnt have been closed. there was a distinct loss of power as well as a change in the whistle of the turbo. the exhaust note from inside the cab didn't change noticably though.

i guess it doesn't matter as long as the problem went away. i just like to understand WTH is going on.

i just put a CPS in it... well, the time you came to the rescue at that hunting camp, and the tech confirmed it was the "updated" part. i do have a couple spares around though

he also did the cruise control band-aid while it was there.

 

[69oiler]

i see there's a P1690 wastegate control valve malfunction on the list above, too. ok i guess i should just ride it out and save up for my V10

 

[93turbo_animal]

i see there's a P1690 wastegate control valve malfunction on the list above, too. ok i guess i should just ride it out and save up for my V10

The EBPV being unhooked does not throw the CEL but it does store a code in the computer. If you were losing power from defueling the sound of the turbo would change as the drive preasure would be decreased. I still think your problem lies else where

 

[Double-S-Diesel]

all my trucks have the 476 code including my old 96, it will not cause a ses light or loss of power.
should have been more codes, need a better ford tech.
havent ever seen a wastegate code on a normal truck, I have lots of them but that because the wastegate is no hooked up.

 

[Agnem]

Interesting thread. Does anyone have a diagram or pictures of where these two sensors being discussed are? It kills me that most thread in seem to involve going to the dealer at some point.. including my own. WE ARE BETTER THAN THAT. There has to be a way! But I think the lack of education in threads like this one have a lot to do with that. Now, I know I have a working EBPV, and I'll be honest... I like it. It DOES warm the truck up faster. I can also tell by the sound when it is working. Rob's description of his problem seems to match what the tech reported. But like he said, if the wastegate sticks open again, how do we troubleshoot that? A lot of us are happy with just 250HP. Transmissions and firmware are another matter.