P0087 Randomly Popping Up

Over the past few days I've been getting a p0087 code, low fuel rail pressure. Sometimes it'll come right back on and others it could be an hour or more. I've read a lot of people saying a couple different things it could be sick as the low pressure pump, high pressure pump, and tuning. Anyone have any advice on this? I drive the truck 160 miles daily commuting to work.

It's got 205k miles and is ******d and tuned. I don't know the details of the tune tho.

It would be nice if I could just drop on a fass pump and fix the problem?

Thanks in advance!


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Forgot to add that the fuel filters have 5k miles and oil has 1k miles.


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Could be a chaffed wiring harness on the high pressure pump hence the intermittent code. Could also be the high pressure pump going out. Spartun tunes were more prone to setting that code but if you have no idea what tunes are in it, I guess that's no help. You need to get a monitor or scanner on it to see what's going on.

I have a cts but it doesn't have the option to watch anything to do with fuel. I'll check on the wiring harness when I get home this evening


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It's a pretty big job to get to it

sootie said:

It's a pretty big job to get to it

Click to expand...

Didn't think about that. Just assumed I could get to it easily lol


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It won't set the code off until I'm around 35-40 mph. You can tell because it jump up in boost and take off a little hard like you accelerated more but the pedal position hasn't changed. It's strange for sure. It's got a light fuel tick when the lights on that can only be heard with the window down and stopped. Clear the code and it goes away.


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Over the weekend I finally had some time to install a FASS pump but that did not seem to take care of the problem. In fact, the code is popping up more often now. I haven't gotten any other codes at all. Could it be tuning related maybe? Really dreading the HPFP install or price to have someone do it.


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a low pressure fuel system typically has nothing to do with high pressure fuel codes. Throwing parts at it and guessing what the problem is seems pretty backwards to me. Get a good scanner on it and see what is going on.

Listen to sootie ^^^

You need to get a device first that will monitor Rail Pressure or find someone with IDS to monitor it.

If you are not getting spikes/drops in RP then it is probably a tune related issue. If you can physically watch RP drop and spike and drop and spike repeatedly while driving (you will probably be experiencing power surges as well as the truck cannot adequately make consistent power from lack of constant fueling) then you have a mechanical or wiring/electrical issue likely. There are several related causes for intermittent RP on a 6.4

Most common is a bad RP sensor in the valve cover, or a clogged fuel filter. Those are easy to fix. Another common item like sootie mentioned is a bad HPFP harness, that's a common issue. The updated ones are better protected.

Next would be your HPFP (K16) has a bad PCV or VCV and is probably kicking the bucket. If your truck has 200k+ mileage on an original pump, you should look into this.

Injection harness in passenger side valve cover sometimes go bad but not often. Same with the main harness, these are hardly ever the cause but it is possible but very unlikely.

Bad Injectors typically don't cause RP issues but it is possible.

Last but not least in very very rare cases....Your PCM needs reflashed back to stock and then re-tuned/re-programmed with your custom tunes and sometimes this will fix it. This is somewhat seen here and there.

Other times you have to swap a whole new PCM in. This is very rare. Like less than 0.05% of people have ever had to do this.

All that being said, sootie is right, you need to get a device and start monitoring your parameters (mainly fuel and rail pressure) first before anything else. On your truck with 200k+ mileage, if RP actually is dropping/spiking and you can diagnose that it is NOT tune related, I would strongly suggest looking into your HPFP (K16) and the harness that is with it in the valley

I just had the same problem. Took to the dealership and the reflashed the computer and reset the fuel tables. Lasted about 2 weeks and it's happening again. Truck is back at the dealership


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