weird problem. help please!

still a noob when it comes to diesels so forgive me if this a stupid simple fix. my 97 f250HD has an intermittent problem where i am driving and it seems like it loses power for a quick second and then goes right back to operating normally. it seems like it might be a defueling problem or maybe like the motor is being suffocated for a second. it does it at all speeds and has a slightly rough idle. i scanned it a few weeks ago. here are the codes i came up with:
P0236- turbo boost sensor circuit perfomance
P0344- camshaft position sensor circuit intermittent
P0470- exhaust backpressure sensor input
p0478-exhaust pressure control valve high input

already replaced the cam sensor because the actual sensor was loose in the bracket so it was vibrating while running. also passed a cylinder contribution test when scanned. truck is 5spd 4x4. not sure where to go from here so any input would be greatly appreciated.

What is the normal maintenance

Sounds like you still have the EBV hooked up. The valve might be triggered while your driving I have had a ebv stick closed before.

dont really have a set maintenance routine yet. just bought the truck a few months ago and am trying to fix all the little things. oil changes and greasing things is done every 3-5000 miles. the fuel filter in the bowl did look kinda dirty the other day though. need to change that.

i believe the ebp is still hooked up. i was thinking of just unplugging it since i plan to delete it later anyway. just have to make sure i get a plug to fool the pcm. where is the plug at to unplug it? looked on alldata and mitchell and neither give me a location. also cant seem to find a service manual for my truck anywhere.

sometimes unplugging it won't solve the problem. I had to wire mine open after it failed, the ebpv was just flopping around causing grief... closing at random times while driving down the road. mine made a very distinct sound while it was doing it though, fwiw..

how do you wire it open? are you talking about using metal wire to hold it open or wiring it to stay in the open position?

Since you changed the CPS, did the power issue go away? Also did you clear the codes?

Instead of d!cking around with the EBPV and sensor, just gut it and be done with it.

Billy T.
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havent been able to clear the codes yet. i would gut it if i had the time. go to school fulltime, work fulltime, and have 4 kids with a fifth on the way. i cant afford to have my truck down for any period of time. been trying to see if i can get a buddy to help me out though.

after i changed the sensor the problem went away for a while. it did it again the other day but it was very quick. not near as bad as before.

97strokerHD said:

how do you wire it open? are you talking about using metal wire to hold it open or wiring it to stay in the open position?

Click to expand...

I used bailing wire to wire it open. My truck has never been considered pretty and isn't for show, and I don't have time to tear it apart to fix it properly. Wire has been on there for ~2 years, no problems since!

where is the sensor at that i need to unplug before i wire it open? plan to upgrade to a D66 in the future but this will get me by until i can afford that.

anyone have any info on the turbo boost sensor circuit code?

http://powerstrokearmy.com/forums/showthread.php?t=51720

Have a read through this before you pull the trigger on a d66... not trying to dissuade you, I own one myself, but there's some good info to be had.

I'll see if I can snap a pic tomorrow of the sensor to unplug and how I have things wired up.

You don't "unplug the sensor," you unplug the ebpv solenoid.
Be the only set of wires running to the turbo, under the compressor inlet side.

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definitely a good read on the D66. might have changed my mind because i want something that has a much wider rpm range. thanks for the link and hope to see a pic soon so i have a general idea to go off of. thanks again

ithumpwheniwalk were you able to get any pictures yet?

79jasper, I was looking around the turbo and saw a 2 wire plug under the intake side. The other end of it looked like it came out of the injector harness on the left side of the motor. Wanting to make sure this is the right plug?

If it's under the turbo, that's it. Nothing else runs through there.
And yes, comes out of the main harness.

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Thanks for the info. Is it possible to gut without removing the turbo? Like take the dp off the exhaust side? Is it pretty simple to get the valve plate out?

Eh, best to pull it so you can remove the piston and block the oil ports.
I did mine when I was putting a SD wheel in. Also did all the orings.

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