CamperAndy

That's harsh and also not true. There are hundreds of possible failure modes that would benifit from gauges of various types and locations but are you going to install gaugues for them all? Are you going to accept blame for an injector that burns out a piston because you did not have a thermocouple on the exhust from each cylinder to see the temperature spread? No you won't so don't blame the OP for a pump failure just because he did not have a pressure gauge.

mountainman

Yeah right - it was MY fault for not having installed after market equipment (at my cost) to guard the factory installed equipment against early failure...

Dr. Evil

Like it or not, JasonblkZ06 is essentially correct. A $40 fuel pressure guage can save the cost of a $1000+ injector pump many times over.

texan15

It goes both ways: factory should've thoroughly tested the VPs' to be sure they wouldn't fail like they do... owners should've installed gauges to keep an eye on the pressures to make sure the VPs' didn't fail. Either way, facts stand that VPs fail, owners need to install gauges, and keep their eyes open.

Busboy

A fuel pressure gauge is indeed a must have on our trucks. If it is THAT important why didn't the factory install them? Probably because they didn't want to admit that they have a DEFECTIVE product. What else has a fuel pressure gauge installed at the factory.....?
Aircraft, because there's nowhere to park up there.

patdaly

Guys, we don't know if the VP is bad, just that a Dealership with an unknown track record has said he needs one.

Get a good LP on, clear the codes, and it will probably be fine, all without enriching people when it is not needed.

mountainman

Now that's good advice... thx

HOHN

I feel a need to correct this. Free-flow volume is a worthless indication of LP performance because of the internal bypass design of the federal-mogul pump. You need to know if it has the ability to generate flow at the restriction represented by the VP's inlet (which varies as the pump demands more fuel)

LIkewise, static pressure capability is pretty worthless, too.

The best way is a "pump curve" type of test measuring flow rates at varying restrictions-- say 8psi, 12psi, 15psi, etc.

The banjo's restriction consumes a good portion of the pump's capability. My original LP (still going strong after 7 years) gave me as little as 4 psi after I added injectors and such. After re-plumbing with -8 lines and (more importantly) fittings, my Fuel pressure never drops below 7psi, which is plenty to keep the VP going just fine.


What causes lift pumps to fail? Almost certainly, it's vibration. When the Cummins Heavy Duty engines mounted the same FM pump on a vibration-siolated filter head, the failure rate when WAY down compared to what it was when it was bolted to a bracket on the block.

The wires to the brushes inside the pump often fail, because they aren't positively located (not potted). So as the pump vibrates, the wires flex back and forth until they fail, like a coat hanger bent back and forth repeatedly.

I suspect that my LP has lasted so long primarily because of the larger fittings, but I suspect that the larger injectors may reduce engine vibration. My truck has had larger than stock injectors since about 18K miles on it.

Justin

mountainman

This is great info Justin - but I'm done advising the buyer any further. I need to draw a line for myself. I've pointed him to this site and now it's up to him to do the necessary research and take necessary action from this point on. This info here will be useful (I'm sure) to those who wish to learn more about this unfortunately very common problem.

Thank you and all for valuable info!

CamperAndy

HOHN - The test for lift pump function in the service manual is a volume test at the inlet to the injection pump. Do you mean to say that the service manual is wrong?

retirednak

Good for you for putting your foot down.

J BODY

p0216 will not always light up the CEL. I have one coming in tommorow that I'm installing a pump on. You can clear the code, drive it at 2500rpm and within a mile or two it will reset the code. It does go "dead pedal" but not often.

FWIW I still run a stock lift pump on my personal 130K 01 truck....and I'm not scared, worried, or even remotely concerned!

JasonblkZ06

If that makes you feel better telling yourself that for forking out all the $ to replace your lift pumps and injection pumps. We all knew the lift pumps are crap and needed to be monitored. Me - I haven't made excuses and done what I knew needed to be done and I have had no problems.

HOHN

Not wrong, per se. Just incomplete. I'm familiar (as all of us 24V guys are) with the factory test for "volume". Keep in mind that they used just tell us to check if we had 8psi static capability.

The volume procedure is a convenient sorta-scientific way to say the LP is "fine", which helps warranty costs.

But it's not completely without merit. The truth is that the VP44 does NOT need tons of pressure to survive. I'd be perfectly happy if I had 6-7psi at all times.

The reality is that lubricity of fuel (along with fuel inlet temps) matters a lot more than whether you have 10psi instead of 5psi.

Think "fire hose" more than "pressure washer" when it comes to plumbing these things. Low recirculation of fuel, optimized flow (more isn't always better), etc are important.

JMO

mountainman

Good for you pal - happy trails then. Here is hoping that you don't ever slip on a banana peel and knock your head on a concrete only to be told by a passer by like yourself that it's your own **** fault for not wearing cleats!!!!

Not helpful AND arrogant... hmmm