Engine/Transmission (1998.5 - 2002) Fuel Pres. Gauge Problem.

[abranz]

Help. After reading about the need to monitor fuel pressure, I had the dealer install a Auto Meter electric 0-15psi gauge, model #4361. The technician installed the sender on the end of a 12" greese gun hose which is installed at the schraeder valve port on the vp44. It worked fine without fluctuation for about 100 miles, then became eratic with 3-5 rapid fluctuations for about a week, then broke leaking diesel out of the sending unit. A second sender was placed and it was smooth for about the same time and now it is rapidly fluctuating and likely is on the way out. What are snubbers and isolators I read about on TDR and where can I get them? If this sending unit breaks, I'm thinking of a mechanical gauge. What components are required for a mechanical system? Please help, feedback greatly appreciated.

 

[Steve Campbell]

The snubber or isolator....

is an inline "orifice" with a small enough hole through it to dampen the sharp spikes in fuel pressure coming from the schrader valve at the VP44.

 

[lsenus]

I used the Autometer 4361 as well. I mounted the sender at the end of a 12" grease gun hose on the outlet side of the filter canister on my '99. So far, 8k mi with the gauage, no fluctuations.

The hose runs up from the filter housing to the firewall, where the sender is mounted horizontally. This creates a nice gentle 90 degree bend in the hose and I assume allows it to drain back when not in use and create an air damper situation in the hose as well.



just my $. 02

 

[jbone]

For what it is worth--I installed Westach and mounted sender right on the filter... year later still working fine..... R, J. B.

 

[RSnaith]

You may want to consider moving the fuel pressure guage install to one of the banjos on the fuel filter canister. We've found that the VP44 spikes, even with a grease gun hose, can tend to be hard on both mechanical and electric gauges.



If you should decide to move to a full mechanical, I recommend using a high quality stainless braided line to make the run inside the cab of the truck, to prevent any accidental chaffing and leaks. Use a good liquid teflon (LocTite PST seems to work very well) at all the joins.

 

[RSnaith]

You may want to consider moving the fuel pressure guage install to one of the banjos on the fuel filter canister. We've found that the VP44 spikes, even with a grease gun hose, can tend to be hard on both mechanical and electric gauges.



If you should decide to move to a full mechanical, I recommend using a high quality stainless braided line to make the run inside the cab of the truck, to prevent any accidental chaffing and leaks. Use a good liquid teflon (LocTite PST seems to work very well) at all the joins.

 

[Big P]

I found this part number from a post by a fellow member. Autometer part #3277 nitrious/fuel pressure regulator. It's a brass fitting with a hole less that a 1/16" on the -4an hose side and 1/8" npt on the sender side. It solved my problem.