ANOTHER FUEL PRESURE QUESTION

[ahale2772]

if there is anyway u can make the path of fuel from tank to the pump as unrestrictive as possible than ur wot pressure wont change much from regular driving best of luck

[Ace]

The pump did rupture the diaphragm to the block, loading it with diesel, but I am certain it was age/mileage (300,000 +/- miles) related, not an incompatibility issue.

I didn't know a 2nd Gen piston pump had a diaphragm.

[PToombs]

I wasn't going to touch that one.

[1STGENFARMBOY]

OK i just came in from the barn, I put on my new walbro pump tonight its suposed to be 11psi and i have 4psi at idle and if i load it a little it drops off to NOTHING, does antbody think it could be the fuel filter, It seems to me if it were the filter it would still build 10 psi with it the pump running and the engine off. PLEASE HELP ME

[Ace]

Either there's a restriction somwhere (filter, pinched line, boogered pickup, etc) or the pump's bad.

[1STGENFARMBOY]

What do you think about blowing down the line into the tank with air, lets say 45psi or so, do you think that would hurt anything. Darwin

[Ace]

Probably not if you have the cap off. You might blow the screen off the bottom of the pickup. But if I was leaning in that direction I would try to eliminate everything else first, then drop the tank to clean and inspect whatever's in there. If blowing the pickup open does the trick you are just delaying the inevitable again anyway. My truck only had 75k on it when I dropped the tank for some related mods and was already showing signs of crud building up on the pickup screen.

[tiny2085]

Are you reading the fuel pressure pre or post filter ? if you read it pre and it's up around 10 or so, and then switch to post filter and it drops to 0, then you kow it's the filter. Why don't you just change the filter if you haven't done it in the last little while

[Mark Nixon]

The pump did rupture the diaphragm to the block, loading it with diesel, but I am certain it was age/mileage (300,000 +/- miles) related, not an incompatibility issue.

I didn't know a 2nd Gen piston pump had a diaphragm.

Yeah, I am a total idiot on these things, but what can I say?

Pulltilbroke has the thing and it does look to have been leaking on the pushrod that rides the camshaft.
He pulled the injection pump last week, too. No leaking pump shaft seal. Imagine that.
All I know is I had a crankcase full of diesel and it didn't leak diesel into the oil after I isolated the piston pump and put an electric one on it.
Drove it another 10-15,000 miles afterwards.

Personally, I'm of the opinion that a good electric pump is more reliable for the fact that it CAN'T leak into the the crankcase.
If it wears out, it just dies, not leak like a stuck pig and take the engine with it.

I have always run only electrics with the gasser engines for the same reason.

BTW, I do have a spare '95 P/P to off.

Mark.

[1STGENFARMBOY]

I just put a new filter on and blew back in to the tank it might have help 1/2 psi or so but still drops off to 0 psi when im on the skinny. So i turned down the power screw 1 full turn turned out the smoke screw all the way, still the same thing, I did put the fuel line directly from the pump to the guage and it read 10psi, But heres whats strange i wired the pump to hot all the time and the pump never shuts off all the way it keeps cycling a little bit, Is there an adjustment on the return line in the ve or could that be causing problems. by the way i have the gauge in the post filter line to the ve.

[Ace]

I just re-read this entire thread and realized I don't even know what pump we're talking about. Exactly what Walbro do you have? I mean the exact model number.....

[Mark Nixon]

Try another guage.
Also, try hooking up an alternate fuel tank, if it's sucking air, the best pump in the world won't help a thing.

Something's rotten in Denmark somewhere.

Mark.

[1STGENFARMBOY]

Ace i think i read somewhere that you have the same pump on your truck , its the saltwater walbro FRB 22-2 8-11 psI 43GPH man i thought this would do the trick. and Mark the guage works when i dead head the pump directly into it and reads 10psi. could the VE be letting to much preshure back into the tank.??

[Mark Nixon]

Ok Richie How can my truck pull hard all the way to 85mph and show 0 psi from 20 mph on up....

To me this is part of your answer.

TRY A DIFFERENT GUAGE.
Or maybe you have and I didn't see it in the topic?

{edit}The pump cycling when it's dead headed is likely normal if it's internally pressure regulated, which it should be.{end}

Mark.

[Ace]

its the saltwater walbro FRB 22-2 8-11 psI 43GPH ...

I think that's your problem. This pump is an autopulse design with built-in regulated shutoff, basically designed for standby, backup or helper applications. That's how it's installed in my Commonrail, in series with the stock pump, as a backup. When I tested it running by itself it would only hold about 2-3 psi under normal light load. Running in conjunction whith the stock pump it "helped" the stock pump maintain 10psi at WOT, where before it would pull down to 6psi. It's purpose in my application is to "help" the stock pump support bigger injectors, or get me home if the stock pump fails - "helper," not primary pump.

I'm not sure of the CP3's requirements vs. the VE, but they are entirely different animals and the CP3 is designed to run on it's own. I think you need the Walbro model that runs constantly full-on to regulated pressure. It looks identical, just not autopulse.

Did you get the idea from an old 3rg gen DTR thread of mine? Man I wish you'd asked me about it first.....