Engine/Transmission (1998.5 - 2002) pusher pump

[cmills]

I have a pusher pump on my truck and with it and the lift pump I have around 17-20psi of fuel pressure at idle. Can having that much pressure cause any harm on the injector pump. I was just wondering if I would be better off with just the lift pump and a fuel pressure gauge in the cab to watch so I can see when its going bad?

 

[Gary - K7GLD]

The short answer - NO, it won't likely hurt the injector pump. I'm running about 22 PSI at idle, 18 down the road, and have been that and higher for over 2 years - so have quite a few others with pusher setups - relax, enjoy an improved fuel delivery system!

 

[cmills]

Here's why I asked, I've be having a problem with my truck starting after it has warmed up so I checked the fuel pressure and it was about 10 psi with both pumps, so I bypassed the pusher and found out that the lift pump was only at about 3psi. Well I left the pusher bypassed because It was going to Scheid diesel to have it looked at because they think the injector pump is going bad. Anyway after I unhooked the pusher and was running on just the lift pump running at 3psi the truck started good after it was warmed up, While with both of them at 10psi it was hard to start. I only tried it a few times with just the lift pump but it started good every time. Does this mean something or is it just luck that it started good a few times?

 

[Gary - K7GLD]

You SHOULD have the pusher wired so that it only functions when the stock LP does - most of us accomplish that by use of an external 20 amp or so relay (Radio Shack item) that is keyed off the stock LP power wiring, and then the relay provides power to the pusher thru a separate dedicated line - if steady fuel pressure of more than 7 PSI exists at the VP-44 inlet, it can be VERY hard to start - don't ask how *I* learned that...

 

[Muleskinner]

Originally posted by Gary - KJ6Q

The short answer - NO, it won't likely hurt the injector pump. I'm running about 22 PSI at idle, 18 down the road, and have been that and higher for over 2 years - so have quite a few others with pusher setups - relax, enjoy an improved fuel delivery system!

I started having a hard start problem when warm. I thought it was my pusher pump. After replacing the injector pump the problem went away.

 

[cmills]

Thanks guys, I do have mine wired so it runs off the lift pump. I should know today if the injector pump is bad.

 

[Steve St.Laurent]

Do you wait for the pumps to shut off before you crank? On my setup if I crank immediately after turning the key on (while the pumps are running) it will take longer to start. If I wait for the pumps to shut off (just a few seconds) it lights right off.

 

[rweis]

On the DTT site about the RASP there is a comment in the RASP thread that they contacted Bosch and Bosch said that 12 - 14 psi is optimum psi input range.



FYI,



Bob Weis

 

[nieters]

they don't like to start with high fuel pressure. i have my pusher set up with a switch in the cab. works fine.

 

[cmills]

I just found out today that Scheid replaced the Injector pump and all 6 injectors because they were about shot as well, so I figured I would get the truck back today. Well, I called about the truck and they said it still has a miss at idle and they haven't figured out what is causing the miss, Any ideas? Anyway what was going to be a 2 day job has turned into 5 and I still don't have it back. I know its not anybody at Scheids fault, its just frustrating. Not to mention I had to take my computer in to get a virus taken off so I don't even have my computer, right now I'm using someone else's. What a week!



Sorry, just venting.