Low pressure pump 20psi???

[Don S]

Re: Low pressure pump 20psi???

Are you absolutely sure you have the hoses from the fuel cell to the throttle body hooked up right? Check, don't just assume. The problem you are having, can't happen.

 

[BreakOutAnotherThousand]

Re: Low pressure pump 20psi???

Yup!
High pressure port side of TB, return starboard side of TB.

 

[BreakOutAnotherThousand]

Re: Low pressure pump 20psi???

Are you absolutely sure you have the hoses from the fuel cell to the throttle body hooked up right? Check, don't just assume. The problem you are having, can't happen.

Don,
Are you a VP dealer/repair, Im curious if specs have changed on this fuel cell VP#21608511.
I might be chasing the wrong horse. Volvo Penta wont speak with consumers, the local repair facilities around here are totally inadequate. Volvo Penta requires a dealer to call.

2 New pumps with the same over pressure on the low side??

Its not the TBI pressure regulator, I ran a pressure test on the return line.

Unless its an internal pump restriction between the low and high pump.

I understand there a float in there, what if its set too low??

 

[Don S]

Re: Low pressure pump 20psi???

If you plugged off the output of the low pressure port, it should not go over specs **8 ?4 psi. If it goes to 22, you either have 10 Psi inlet pressure, or the pump is bad.
To have two brand new pumps doing the same exact thing, 6 months apart is highly unlikely. Since Volvo sent you the pump and regulator, call them back. Explain the situation with your dealer. I haven't worked for a Volvo dealership since late 2007.

 

[RickyGee]

Re: Low pressure pump 20psi???

Volvo produced 5 different pumps in 5 years, all interchangeable. The 21608511 is the latest in the series, but the official USA Volvo web site doesn't recognize that part number yet, while they deplete the inventory of the previous version. Obviously, they are chasing reliability issues. One of the previous versions was failing because some genius decided it was a good idea to paint the inside of the fuel cell and the paint is peeling off and clogging the screens and check valves, causing the high pressure pump to cavitate and fail. Brilliant.

Volvo issued a service bulletin P-23-7 that actually removes the screen from the pressure regulator because a clogged screen can cause abnormally high fuel pressure and poor engine performance (DUH). I think this is a really dumb idea, since the garbage being shed by the fuel cell then just clogs the injectors instead. But a check of the screen on the regulator for contamination might be in order.

I agree with Don that the low pressure pump (the one on the right side, opposite the filter) should put out only 8psi or so. Unplug the electrical connector on the HP pump and turn on the key with your test guage installed on the manifold test port. If the pressure is higher than 8-10 psi, then you have a restriction in your system.

 

[BreakOutAnotherThousand]

Re: Low pressure pump 20psi???

Thats not my fuel system.

 

[BreakOutAnotherThousand]

Re: Low pressure pump 20psi???

OK.

Im baffled.

Everything lately has been hinting to me it's a timing advance issue. (Mind you I was an ASE Master tech in my youth)

So I pulled the distributor.
It was a replacement from Mallory Marine, as it was less expensive for a distributor with cap rotor wires and coil, than just a cap rotor and wires from Volvo.

Granted the misfire/lack of power was there _before_ I replaced the ignition system. I reinstalled the OEM distributor.
The engine now runs like a raped ape!!

What happened??? The first thing I learned at 15 was how to R&R a distributor.
Im tempted to reinstall the Mallory, to see, maybe a bad wire?? Did I move a wire from the ECU, the ignition module gets its advance from the ECU.
My mechanical instinct tells me to do it, just to see if it happens again. My personal logic says to leave it alone, but if I dont get to the root of this, Ill be on a lake with the problem reoccurring.

Yes, I have a Rinda shunt, yes I used a timing light with advance, so I set it to 8 and timed it to line up with the mark.
Both times timing was dead on.

 

[BreakOutAnotherThousand]

Re: Low pressure pump 20psi???

OMG, I just realized what I did!!! I set my timing light to -8 degrees, not +8, timing was retarded 16 degrees the first time!!!

 

[Don S]

Re: Low pressure pump 20psi???

Timing has absolutely nothing to do with the high fuel pump pressures you were seeing.

 

[BreakOutAnotherThousand]

Re: Low pressure pump 20psi???

I agree with you on that issue.
However the high fuel pump pressure was not the cause of my loss of power, backfiring etc.
Its another mystery!!