Fuel Pressure Sensing Point

[Double 6]

I am wanting to hook up a fuel pressure gauge after the filter, I will be using a tapped banjo bolt from Geno's to get into fuel system. I have read in several posts that when you come off of the injection pump banjo, you get severe pulsation that can damage gauge sender. Can you use banjo on bottom of filter canister for a sensing? Or does it make any difference? Which place would be better?

 

[JohnB]

It won't make any difference which banjo you tap into, although the one at the pump is easier. The 12 valves would pulse the gauge sender due to the mechanical lift pump operation, the 24v has a steady presure until the pump gives up.

 

[Bob Cochran]

I had my Autometer connected on the VP44 and it did not work right jumped all over, etc. Today connected it at the bottom of fuel filter and it works just fine. I guess I should have bought a gauge that read higher than 15 PSI as it reads about 16 at idle though.

 

[WOT]

I have installed a Autometer electric fuel pressure guage (0-15psi)at the VP44 supply fitting using one of the modified banjo bolts with 1/8" tap. My guage would peg out and then occasionally drop and jump all over the place at WOT. I thought the guage (or sender) was bad and ordered a replacement. It hasn't come in yet due to a shipping backlog. Maybe the problem is just location. My concern is if I move it from to the filter I won't know if the filter is plugged up and reducing pressure to the pump itself. Any ideas on whether or not moving the sensor off the fitting with a rubber line would help?

 

[Snow man]

Im going to put 2 senders,one before ,and one after the filter,and use a toggle switch,to switch between the 2 senders.

 

[Bob Cochran]

WOT ~ Thats the way mine acted unitl I moved it. Now it reads more than 15 at idle so hoping did not hurt sender. There are 2 fittings one at the VP44 from filter (schrader) and on the other end of the line at the bottom of the fuel filter a banjo fitting. I Exchanged the 2 and put scrader at fuel filter and connected FP gauge. Both locations are after filter so you can tell when filter is plugged both places. The other fitting is alread a schrader on the back side nearest firewall it is the incoming fuel line from tank and before filter.

 

[RustyJC]

I have a dual combo Westach fuel pressure gauge that reads pressure before and after the fuel filter. I installed Ray's 1/8" NPT banjo bolts at the filter inlet (back side) and filter outlet (bottom) fittings and plumbed back to the two sending units with stainless steel braided hose.



Everything was fine until this Saturday when the post-filter needle started swinging wildly from 16 PSI to 0 PSI and everywhere in between - the pre-filter needle was rock-steady as usual! Looks like a bad sending unit on the post-filter side. I don't know if this is a fluke, or if I'm picking up pressure spikes feeding back from the VP44 that have knocked the sender out. I'm going to order a replacement sender today and send the defective one back under warranty - that way, I'll have a spare. Looks like remote mounting may not be absolute insurance against sending unit failures, either (although I would think it should help).



Rusty

 

[Bob Cochran]

HHMMM maybe we need to add some kind of isolator to try and dampen this to not cause damage to the sender if that is what is happening?



I guess I should clarify something; my sender was not mounted directly to VP-44. Sender on firewall and connected using 3 feet of braided stainless steel fuel line.

 

[Double 6]

Bob,

Have you had anymore trouble with sender/gauge since hooking to bottom of filter? And are you still using your braided line to sender off bottom of filter?

 

[BigDaddy]

I am using two of Ray's tapped Banjo Bolts, at the inlet and outlet of the Fuel filter. These are mounted directly to the banjo bolt. I have not seen a problem with this setup.



Connecting a pressure sender (directly) to the inlet of the VP44 is not recommended. Many have seen erratic readings in this location. Some have used this location with success by remote mounting of the pressure sender and/or employing a pressure snubber to dampen the pressure spikes.

 

[cullyguy]

I put in a Westach Fuel Gauge a week & a Half ago. Tapped Banjo Bolt / Off of Bottom of Filter housing. Got about 13-14 lbs pressure @ idle. 9-10 @WOT W/ DD box set in the middle setting. Then a few days later the pressure dropped off and the needle on the gauge was bouncing all over the place. Sort of jumped the gun & put a new lift pump on order from Cummins. Just in case I called Westach to get some help. The person answering asked if I had the two wire sender, I said yes, he said I'll send you a new one, the pin inside the sender sticks & causes the erratic readings. I now have new a lift pump on the shelf for future reference! That was last Friday, the new sender is no here as of today (9-18-01). I got a hose made up to remote mount it when the new one shows up.

 

[Bob Cochran]

Double 6 ~ When I connect to bottom of filter the erratic operation of the guage stopped. Really only problem is at idle it registers approximatley 16 PSI now on a 15 PSI guage. I am thinking 14 PSI would be normal (it read that reading before going weird). I suspect I have damaged the sender somehow. I am trying to work this out with Autometer at the moment as we have had a minor disagreement on interpretation of my email describing the problem to them. I suspect it will be resolved.



A fellow owner of a similar truck and same fp guage in Tucson. When he moved connection to bottom fuel filter it settled down and read 14 PSI at idle; similar problem connected to VP44 schrader valve. I think BigDaddy maybe right if connect directly to VP44, even remoting the sender, a pressure snubber maybe necessary. This is my thoughts only from my experience so far with the Autometer 2661. May not reflect on other peoples installation. How about that for a disclaimer!!



Hope this helps those using this guage from having similar problems. It would be cool though if the pump was really putting out 16PSI, WOW!!!

 

[Double 6]

Thank You Bob and the rest of my fellow TDR members for all the valuble info. I will tie into bottom of filter with tapped banjo and remote mount with a hose, it should do the trick.

Dodge truck-$35,000

Accessories-$5,000

TDR Membership-Priceless

 

[Bob Cochran]

Double 6 ~ Your welcome and I forget to tell you that yes I still using the braided stainless steel line with aeroequip fittings. Probably overkill but looks good!!

 

[WOT]

I believe I will also remote mount via hose from the bottom of the filter. If the sender sits higher than the filter the air in the hose should provide some dampening to help protect the sender...



Membership is priceless!

 

[Bob Cochran]

Talked to Autometer today they will be sending me a new sender without charge. Will see if this helps and I see around 14 PSI instead of 16 PSI.

 

[hv2hunt]

fuel isolator

Just wondering if anyone has used the fuel pressure guage with the isolator from autometer?

If so how did it work? or is the electrical one the only way to go?

 

[cullyguy]

Westach sent me my new sending unit for my 16lb gauge. I got it remote mounted on the firewall up near the hood hinge, used about 26" long hose I had made up @ a hose shop. Gauge seems to read about 1lb higher than before, with less drop @ WOT. I hope all is well, but I have a new lift pump on hand just in case.

I have to say Westberg (Mfg. Company for Westach) was very prompt in getting me my replacement sender.