Fuel pressure gauge part 3?

[bgilbert]

Thought I'd update everyone that has followed any of the fuel pressure gauge threads and or asked about a FP gauge. Well I've killed my second FP gauge. This time it was my old 30psi boost gauge I used as a FPG. As some of you may know, you can use any pressure gauge for a fuel pressure gauge. I killed my original Isspro EV series mechanical 'fuel pressure' gauge less than a month after installation. My old Isspro ev boost gauge got put on to use afterwards. It lasted quite a bit longer than the gauge that was designed for fuel pressure ! Well two months instead of less than a month . Both setups I had live fuel running to the gauge in the cab. This is actually bad as the pulses from the lift pump/camshaft will destroy the FPG. I didn't have any use for the old boost gauge so I went ahead and made it walk the plank. So the correct way to run a mechanical FPG with a mechanical lift pump, be it diapraghm or piston type, one would want to use some form of a snubber, isolator, needle valve?, anything that will dampen the pulses of the lift pump/camshaft before the fuel reaches the FPG. IF I were to do this all over again, Id definitely go with an electrical FPG. Although I've heard they have problems of their own. FWIW, a mech FPG alone runs about $50, a boost gauge runs about $30, both will work, one might last longer though, and you can tell people when they ask whats with the other boost gauge, you can tell them its for your bottom turbo in your set of twins :-laf . Course some just gotta have their gauges read the correct thing its measuring.

 

[Greenleaf]

I'm loving my electric Westach. No fuss... ... ... ... ... no mess.



GL

 

[vhainesxx]

Needed?

Hey guys how important is a fuel pressure guage? What kind of readings do you take from it while bombing? :-laf . I'm wondering if it is something I should put on my truck? Hey GL I'm gonna give you a call and chat in fews days if thats ok.

 

[Greenleaf]

I have to assume that you have my phone # ?????



A FP gauge isn't all that important to a stock first gen truck. However it is advisable to test the LP delivery psi on ocassion. Do this by connecting in a gauge to a tapped banjo and take it for a drive. You'd want to see no less than ... ..... say three (3) psi IMHO



If you boost fuel flow through the injection pump to the point of becoming a tad wild... ... ... ... ... you would want to monitor that a bit closer... ... . IMHO



-S

 

[swankmetal]

do you thinks it's needed with the piston pump mod, gl?

 

[Greenleaf]

If you have install a higher flow/ increased psi lift pump, be it piston or electric it would be advisavble to at least check the supply side pressure to establish a base line while the engine is under a loaded condition.



I simply installed a (electric) fuel pressure gauge because I could. One wouldn't have to have a permenant installation. Again, MHO



GL

 

[Greenleaf]

I just lost (another) VP-44 !$@#



Maybe it would be best to install a LP pressure gauge on all my ISB engines???? It only has 39,180 miles. Praise be the 12 valve engine.



GL

 

[JLEONARD]

Bill,

So... if you installed a shut-off valve ahead of the actual gage, and only "activated" the gage occasionally to monitor the fuel pressure, the "old boost" gage could last years...

Correct?

Jay

 

[bgilbert]

Jay, yep thats a good idea. BTW anyone looking to donate a 30psi boost gauge for R&D let me know.

 

[nascar mark]

Thought I'd update everyone that has followed any of the fuel pressure gauge threads and or asked about a FP gauge. Well I've killed my second FP gauge. This time it was my old 30psi boost gauge I used as a FPG. As some of you may know, you can use any pressure gauge for a fuel pressure gauge. I killed my original Isspro EV series mechanical 'fuel pressure' gauge less than a month after installation. My old Isspro ev boost gauge got put on to use afterwards. It lasted quite a bit longer than the gauge that was designed for fuel pressure ! Well two months instead of less than a month . Both setups I had live fuel running to the gauge in the cab. This is actually bad as the pulses from the lift pump/camshaft will destroy the FPG. I didn't have any use for the old boost gauge so I went ahead and made it walk the plank. So the correct way to run a mechanical FPG with a mechanical lift pump, be it diapraghm or piston type, one would want to use some form of a snubber, isolator, needle valve?, anything that will dampen the pulses of the lift pump/camshaft before the fuel reaches the FPG. IF I were to do this all over again, Id definitely go with an electrical FPG. Although I've heard they have problems of their own. FWIW, a mech FPG alone runs about $50, a boost gauge runs about $30, both will work, one might last longer though, and you can tell people when they ask whats with the other boost gauge, you can tell them its for your bottom turbo in your set of twins :-laf . Course some just gotta have their gauges read the correct thing its measuring.

Bill,



I hate to say I told you so, but as I mentioned to you when you wanted warranty on that gauge, you need to run a isolator or what ever mechanical gauge you try to run will fail. No matter what you think a gauge should be able to do, they need some type of buffer from the shock load of the lift pump. Because you didn't want to pay for a isolator, I told you I wouldn't warranty the gauge unless you install a isolator. Lessons learnt the hard way. My offer is still good to you Bill. Do it right and buy a isolator and I will warranty the gauge.

 

[Greenleaf]

When I test a p-pump supply from it's lift I use a ball valve in line with my mechanical test gauge. I pinch off the flow to the point that the needle stops bouncing. Some guys simply fasten vice grips to the flex hose and regulate how tight the 'grips are. This serves to dampen the gauge and offer a reading.



I have a mechanical gauge here that has some kind if buffer in it(????)as it does NOT bounce with the fuel lift pump pressure spikes. I don't know why it will not bounce, but I have yet to see it do so. It's a 3 5/8" Autometer fuel pressure gauge. Got it from NAPA, 'bout seventy bucks.



GL

 

[bgilbert]

Bill,



I hate to say I told you so, but as I mentioned to you when you wanted warranty on that gauge, you need to run a isolator or what ever mechanical gauge you try to run will fail. No matter what you think a gauge should be able to do, they need some type of buffer from the shock load of the lift pump. Because you didn't want to pay for a isolator, I told you I wouldn't warranty the gauge unless you install a isolator. Lessons learnt the hard way. My offer is still good to you Bill. Do it right and buy a isolator and I will warranty the gauge.

 

[michigandon]

Added the piston lift pump over my last days off, along with the updated banjo bolts. I had originally planned to install a Westach electric fuel pressure gauge as well (needed something to replace the now-defunct Isspro tachometer in my custom dashboard ). However, I decided that I didn't wanna wait around 10,000,000 years for Westech to get off of ther fat lazy ***** and produce any more. so I installed a Holley electric gauge insead:



http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=1588&prmenbr=361



So far I'm showing around 12PSI at idle. Dunno about full throttle or cruising speed as the rig currently isn't driveable at this time (you can blame Philip for that :-laf ).



It's probably just a psychological thing, but I swear this thing is idling much smoother since the new lift pump too!



Don

 

[Philip]

(you can blame Philip for that :-laf

:-laf :-laf Don't you just hate it when you get the wrong parts.

 

[michigandon]

Like I told ya Philip, everything else on this contraption has required multiple trips back to the store. Why should this phase of the project be any different?

 

[SScandalis]

You bet that the first thing I do after I get my rig back is to install a fuel pressure gauge on the "output" side of the fuel filter. I want to know that the Transfer Pump is operating correctly AND that the fuel is flowing with proper pressure through the filter element to the Injector Pump. Looks like it's any easy hookup with the built in before/after test ports on the fuel filter canister.



I'm on the verge of a Transfer Pump and a VP44 Injector Pump change on my '98. 5 24-valve with only 66K miles. Truck is in the shop now. Diagnosis indicates that low 5 PSI pressure from the Transfer Pump has starved the lubrication and cooling fuel flow needed to keep the VP44 smiling, causing the infamous "Injector Pump Timing Failure" engine check light/code.



Still seems strange that the '98. 5 Cummins VP44 can't survive low pressure and alert the user in some other manner prior to the Injector Pump code.

 

[DieselTweaker]

I need to get a FP gauge on mine, just so i know how much Im running, and how much it drops, on the wood.