Intermittent p0088 high fuel pressure

mrbudge · March 19, 2010

We have a 08 F550 wrecker here, every once in a while it will put on the mil and set p0088 high fuel pressure. The driver says it runs rough when this happens, it is always cleared up by the time it gets here and we haven't been able to duplicate it. Back in January we put in a fuel rail sensor and UVC harness and it was ok until recently. Of course being a tow truck they can't leave it too long for me to get a good look at things. Anyone come across anything like this before? It is supposed to be here to greet me on Monday morning. Thanks in advance, Dave.

GregKneupper · March 20, 2010

Every time I have a p0088 it was an injection pump that was causing the problem. Most were intermittent but I could eventually duplicate them. The pcv valve in the pump will stick at times and cause the fuel pressure to go to high causing the engine to derated. But that is not to say yours could be a different concern. Another place to check is the injection pump harness. Some times the ground wire to the valves can stick and also cause a p0088.

Keith Browning · March 20, 2010

Recall I had an issue that eluded me and a Navistar FSE for a while but that was a P0087 DTC. Clicky here to read if you wish. In reviewing the pinpoint tests for P0087 and P0088 we can see that the diagnostics are similar. Keep in mind I was chasing a low pressure concern and had a problem with the VPWR circuit that fed the PCV and VCV... you have a high pressure concern which leads me to suspect a sticking valve or a PCV/VCV ground side circuit concern. Although it doesn't list DTC P0087, TSB 07-26-2 identifies the pump gasket as the cause for several DTC's and lack of power for 2008 F-Super Duty vehicles built prior to 8/20/2007. I can see an intermittent short to ground on either circuit CE321 or CE328 causing erratic PCV or VCV operation.

We have heard of a lot of pumps being replaced for sticking valves - be forewarned that fuel contamination or RUST will void warranty coverage. Personally, I would lean toward a pump. At the very least, accessing the pump will allow you to examine the wiring before you toss a pump and gasket at it. Posted Image

joshbuys · March 21, 2010

I've also seen a short in the pump harness on a vehicle with the updated gasket/harness already installed, remember, just because it falls out of the build date or has already been repaired with the update, doesn't mean the updated part can't fail!

We should always make sure to KISS.

I have to agree with Keith, sounds like a sticking VCV/PCV or shorted ground on one might be a good contender on this one.

Jim Warman · March 21, 2010

No VDR?

March 21, 2010

We had one with a 0088. Tech found a shorted wire on the pump gasket. Hotline said to replace the gasket only. So, he just replaced the gasket. A week later, the same code came up. He replaced the pump this time. That was about 2 months ago, so far its been ok with the new pump.

mrbudge · March 22, 2010

No VDR available. Also no circuit fault codes for vcv or pcv. We are leaning toward pump also. Thanks for your input.

DamageINC · March 22, 2010

I had a repeat P0088 or P0087 once on a truck that had a shorted pump harness.. replaced the harness the 1st time, vehicle left and came back about a week later with the same codes again. Found an "open" ckt for the PCV circuit at the connector for the new harness, if I remember correctly.

Off with the body and did the job again to find that the connector had come unclipped from the pump. There was a batch of bad harnesses, I guess.. the problem is that the locking tang/clip that actually locks the connector in place would get hot, and WARP, bend itself into a position that prevented it from securing the connector to the pump and squeeze itself in and out causing the concern.

I also recall hearing about people not realizing that the silicone packing/seal on the connector would sometimes stick inside the pump when unplugging the old harness, and then the NEW harness would get plugged in on top of the old packing and it created too much tension and either broke the tabs off of the harness connector or just never properly locked in the 1st place and came loose over time.

Or, it could be a faulty pump at itself, hehe... eithe rway, it looks like you might be doing the job again, which sucks. At least it's likely that it wasn't something you missed or overlooked.

Dave

GregKneupper · March 23, 2010

The newest harness kits come with tie straps that you install through the connectors so that they do not become dislodged.

Brad Clayton · March 23, 2010

6.4 Liter HPFP kit

Posted Image

As per the instructions, seal removal:

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And finished look:

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Mekanik · March 26, 2010

I'm battling one with the exact problem right now. The hotline engineer I'm dealing with thinks I have a PCV or VCV that intermitently sticks or has high resistance. We have NEVER actually been able to duplicate it. BTW, the PCV, VCV resistance spec is 1.5-8.0 ohms.

Aaron · March 26, 2010

1.5 to 8.0 ohms is a pretty wide spread...

What do you want to see? Closer to 1.5? Closer to 8.0? Somewhere in the middle?

What about comparison of two units with similar mileage? Do they come up the same?

This is confusing.

Wait..wait....I got it... I know the answer: Posted Image

Mekanik · March 26, 2010

I have checked it several times in the past few days and there are within 3.1-4.2 ohms.

Aaron · March 26, 2010

On that truck, or a couple different ones?

I just kinda wish the specs were a little tighter than that, ya know?

Aaron · March 26, 2010

I mean, if you get one in for a harness failure, no start, and you check it out and it ohms out at say...7.1 cold, well, that's within spec...but what is it at when it's hot? Does it fail hot?

I hate the pump replacement procedure on these...if it wasn't so ignorant to replace, it wouldn't be near as much of a problem, yanno?

Mekanik · March 27, 2010

That was just for this specific truck, but I looked at my notes and there is another one I battled for a P0087, and those solenoids were 3.5-4.0hms. This was a while ago, and at that time the hotline engineer I was dealing with told me that it should be under 10ohms, so I guess that is a little improvement.

The hotline engineer I’m dealing with on this current truck told me to put a HP pump in it, and before that my manager told me to do the same thing.

I really don't mind replacing pumps on these engines, what I don't care for is situations like this where I can NEVER get the problem to act up, but I kind of need to do SOMETHING.

At least it's Friday. Posted Image

Aaron · March 27, 2010

Is it just a regular pick-em-up, or is it a cab/chassis with about 85738 added on pumps, cables, wires, and all that other shit?

Mekanik · March 27, 2010

It's a stake bed and a total work horse with almost 100,000 miles on it. I think the truck runs 8-10hrs a day.

Aaron · March 27, 2010

How many hours? Posted Image

You DID see the warranty action notice, didn't you?

Mekanik · March 27, 2010

3486, with 94,710 miles. Is that a lot?

joshbuys · March 28, 2010

3486 x 25 = 87,150 = driven more than idled, completely acceptable per the warranty action notice.

robp823 · March 31, 2010

Just had the same thing in the shop.P0088.Followed ppt test and it ended getting a pump.Mine too was fuel pressure to high.Had to be one of the solenoids sticking.Took forever but i finally got it to act up for me.

Mekanik · March 31, 2010

Mine will be done tomorrow. I put a pump in it, but was NEVER able to duplicate the problem. I was completely honest about that on the prior aproval form. I thought it might be difficult to get authorization because of that, but they gave it to me right away.

robp823 · March 31, 2010

The only thing that they gave me trouble about on my prior approval was when i sent it the first time they sent it back saying they wanted the pump gasket ohm test results with engine hot.Once i sent them the results they gave it to me right away.

BrunoWilimek · March 31, 2010

The only other diesel tech in the shop here just got done replacing one of those high pressure pumps for the same code P0088, he was never able to duplicate symptom. Truck had been to two other shops who just cleared the code, reprogrammed PCM and sent him on his way. I can see why too. It was his first cab-off 08 Super duty repair and he lost his shirt on the job. Including all the diag time, heating the cab mount bolts, spinning one and having to remove the headlamp to weld the cage nut, getting propr approval and all, he was on it for 3 days and only got a little over 8 hours. Not a real nice job. He's almost ready to quit. Posted Image