Low boost on 97 PSD OBS

[JMWRIGHT335]

That is correct, Yes I have checked the EBPV, sensor reading are above and the valve itself is free by hand and fully functioning electronically.

 

[79jasper]

Yes, but is that a "normal" reading?

Oh also, IMO, your fuel pressure is a little low.

 

[JMWRIGHT335]

Yes the EBP is reading correctly, you should see 16 at idle and approximately 19 at wot.. And I agree the fuel pressure is low as stated in post 11 above im going to be checking into a possible ipr issue in the morning. Any input on diagnosis of HPOP?

 

[79jasper]

Only thing I would know for hpop, is putting a gauge on it to check the pressure.
Cat "makes" a set for their heui engines that'll work.

 

[OLDBULL8]

Don't know about the 97's IPR, but the 99 and up have a tin nut that holds the solenoid coil, if that has backed off then your CP will be low. I get about 14 - 15 boost on my 99.5 at WOT, peddle to the metal, about 25-30 WOT pulling a 11500 lb 5er on acceleration.

 

[lindstromjd]

Don't know about the 97's IPR, but the 99 and up have a tin nut that holds the solenoid coil, if that has backed off then your CP will be low. I get about 14 - 15 boost on my 99.5 at WOT, peddle to the metal, about 25-30 WOT pulling a 11500 lb 5er on acceleration.

OBS is the same style. IPR has a nut on the back of it.

 

[rsrace]

I fought almost identical issues - including finally eliminating the ebpv and replacing the turbo...still could not get boost over about 8psi. I went through IPR, oil change, etc. Be sure to check the screen on the fuel pressure regulator - although you are getting pressure, could flow be restricted? Beyond that you may need to look at new injector o-rings. That turned out to be my culprit - losing HPOP through the o-rings even though I was not seeing any fuel bowl discoloration or smoke. I ended up also doing a mild injector change (baby swamps) because I had almost 200k on my inectors. The difference was night and day and immediate...without a chip (which I added later).

 

[JMWRIGHT335]

Replaced oil, oil filter, and fuel filter with OEM Motorcraft parts then performed BB mod and cleaned fuel rpessure regulator screen which was blacked out. Acceleration is "Better" but still falls on its face at WOT.

RSRACE, How did you come to this realization of faulty injector o-rings? I assume you needed to remove the injectors?

 

[rsrace]

Replaced oil, oil filter, and fuel filter with OEM Motorcraft parts then performed BB mod and cleaned fuel rpessure regulator screen which was blacked out. Acceleration is "Better" but still falls on its face at WOT.

RSRACE, How did you come to this realization of faulty injector o-rings? I assume you needed to remove the injectors?

I had pretty much eliminated everything else. It was getting fuel pressure. It had a new open exhaust. I had new IPR/o-rings, new turbo, and pretty much all you did. The High Pressure Oil is what fires the injectors. If the o-rings are leaking the injectors cannot dump the same fuel (pressure can't get high enough). Certainly a failing HPOP can cause the same symptoms.

However, OBS PSD injector o-rings are notorious for going with mileage - some say we should be changing every 150k. You are lower mileage but assuming they are original o-rings they are certainly aged. So if I were faced with new o-rings that I had to do eventually or new HPOP which cost more...o-rings it was. I chose to change the injectors too because, yes, the o-rings requires removing the injectors.

However, your last comment struck me a little different than my situation - I didn't have power at any speed and it eventually got worse with hotter temps like getting off the highway. It makes me wonder if you are starving for fuel at WOT...do you have a way to measure the fuel pressure at WOT under load? Might be fuel pump? <cheaper/faster>

A good writeup for the o-ring change can be found in the repair section on Swamps website (I used Baby Swamps for my injectors and love them): http://www.swampsdiesel.com/site/in...ns/7.3L_Injector_Removal_and_Installation.pdf

 

[Diablo Blanco]

Was there ever a resolution to the OP problem?

 

[79jasper]

Nope. He hasn't been back since 2013.
You having the same problem?

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[Diablo Blanco]

Nope. He hasn't been back since 2013.
You having the same problem?

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I am, nearly identical except I have a manual trans

 

[79jasper]

Start a new thread. Be very detailed.

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