Engine/Transmission (1998.5 - 2002) fuel pressure reads 4.5 at full throttle

[zstroken]

got the autometer 4313?? mechanical with isolator hooked up.

Idle 12. 5 psi, full throttle 4. 5 psi. How do i check if the install is good. I mounted it on the master cylinder, and tapped in to the vp44 pump with a banjo, but used a nipple and fuel line with clamps from the vp44 to the isolator. I have a 2001. 5 truck so is my lift pump shot?

 

[lsenus]

Make sure the isolator is oriented correctly. The bleed screw MUST be on the top side of the installation, and at the highest point of reference. That is to say, if mounted verticaly, it MUST be in the 12 o'clock position. If mounted horizontally, it must be on the topside of installation. Make sure to bleed the air out of the system.

If all this is done correctly, it sounds like a failing pump. CHANGE IMMEDIATLY!!

 

[zstroken]

fuel pressure reading

what about the glycol side?? i made sure the isolator was full then i screwed it on. I did mount the isolator with the bleed screw on the six o clock side due to the mounting location. Once i bleed it on the 12 oclock position, can i turn it back around to the 6?

 

[lsenus]

As for the mounting, I think so, but any air that gets trapped, will have to be bled out periodically. Make sure the Glycol side is full as well. It will be near impossible to get the hose end higher that the gauge to fill the line. Try getting everything set in place, then removing the gauge and filling the line and the back of the gauge in the cab. Then, quickly put them together. Be careful not to spill if possible. Put a rag under your work area to catch any spillage before it gets on your interior.

Send me a photo of your installation if possible.

 

[jtisdale]

I had problems at first after I put my gauge in too. I have the same part# you do. I was questioning my gauges readings to the point that I bought one of Briar Hoppers test gauges. Sure enough, a week and a half later my lift pump was dead. I had like 13 at idle, 10 at cruise, and about 5-6 WFO. My gauge also fluctuated 1-2 psi hooked at the outlet side of the filter. Since the new lift pump, NO fluctuations and solid 14, 12, 9.

I am not saying this is your problem, but if you can borrow/buy a test gauge to double check your readings it wouldnt hurt.

Best case, its not dead, but pretty weak. When mine went, the pressure dropped from (cruise) @12 psi to 0 psi in a matter of 15-20 miles.

 

[zstroken]

rebled it

Went home and rebled it. Went up about 1 psi. 13 psi at idle and about 5 psi wot, I guess i will change the fuel filter and see if it helps, only have about 6,000 miles on the truck though. I wander if i am getting into trouble using a 36 inch piece of regular fuel hose with two nipples on the ends, ihave the clamps plenty tight.

 

[lsenus]

From what I've read in various posts, it's not uncommon to loose a fuel pump in the short time you've had the truck.

 

[rspinks]

I only have 14000km and had 12/9/5 psi when I got Briar's test gauge at 8000km. DC replaced the pump this morning, now 15/12/10 and I'm much happier.



Rich

 

[lsenus]

I just went through a lift and injection pump failure my self. See



https://www.turbodieselregister.com/forums/showthread.php?threadid=49319

for details.



Obviously, I now have installed gauges and see 14. 6 psi at idle, 12. 2 at cruise @ 70 mph, and 9. 4 at WOT. Oo.



I was wondering though, if 17 psi max boost is right for a stock truck?

 

[rspinks]

Don't have a gauge yet but I think you're in the ballpark, maybe slightly on the low side. Seems 19-20 is more common.



Rich

 

[lsenus]

Thanks for the info.