My Commander Fuel Sender Unit is a piece of junk and the signal jumps all over the place, usually settling on "0". I tried everything to fix it, including changing the orientation of the sender, adding grounding straps, adding a needle valve, ad nauseum. I finally called Quadzilla and they said they no longer offer the FP kit because the sender manufacturer (Datcon) had reliability and quality control problems (Duh). They said they are testing out a few different senders from different manufacturers and would probably have a replacement in a month or so. They will also offer some sort of trade in program, although he wasn't specific about that. I asked him if we could use 100 psi senders and just change the controller to the 100psi setting and he stated that most 100 psi pressure senders don't really work below 40psi.

As a matter of clarification, the Datcon sender is an OIL PRESSURE sender, and any oil pressure sender should work. The problem is that I can't find any 40psi models out there. They are all either 80 or 100.... If you have info on a 40psi sender let me know....

 

Look into stewart warner stuff.

 

I have gone through
1-100psi sensor,
2-40psi sensors
1-supposedly heavy duty 40psi sensor

All of them broke the same way you were talking about.

Quadzilla is like you said looking into new stuff and i am sure with their customer service reputation they will come thru but until then were out a fuel pressure sensor. Kinda ticks me off.

How does the Stewart warner stuff work

 

Can't say for sure how they work, but I've got about 6k miles on the one that came with my adrenaline and no issues to date. I think it was stewart warner but I really don't know.

http://www.stewartwarner.com/Catalog/sdrpress.html

Maybe something on that page will be of use to you.

Shawn

 

The problem is that stewart warner is built by Datcon. We have went through every single possible thing we can at Datcon and it does not work and their warranty is non-existant.

So basically we are their warranty house even though we buy them from them with a warranty.

We have a different manufacturer right now and it looks promising so we will see what happens.

 

Well disregard everything I said then! Always easier to get it from the right source.

 

Thanks Quad we know you wont let us down.

 

wooooowwwwww...the needle valve didnt smooth things out for ya....it did with mine...went from very sporatic numbers to a very smooth reading...try that needle valve again and adjust the position of the needle very slighly..i had to fiddle with the opening and tighting of mine a few times and had to do a few test drives to make sure it was right but i finally came settled....only once in awhile does my unit give a sporatic number..ie a flash of 12 psi or 14 psi or 11 and those are only for the breifest of seconds... and it has yet to ever fall below 9 psi....i idle at 20-19...normal acceleration 16-19 and WOT 15-17

NCA

 

The new ones do not bounce but, the resolution is not as good.....sort of a trade off I guess?

There are not really any good sending units, we have looked at autometer, dipricol, westech etc.....most of them are all built in the same place and have the same issues.

 

i used a 18" grease gun hose and a snubber and then the sending unit this takes the engine vibration and both pump surges off of the unit will see if this works

 

It is very probably that isolating the sending unit will work. I am just not going to sell something that makes everyone go "rig" something up on their truck to get it to work properly.

The manufacturer we have worked with has known from day 1 what we were doing, how we were doing it and why we were doing it. The have mislead, lied, and cheated since that day and we are doing everything we can to try and save face over something I really have little control over.

In the end it we will make it work. I think we already have a solution we just need a couple of minor detail to be worked out and we will be good to go.

 

NCA, how is your sender hooked up? What type of needle valve do you use? Mine is isolated from the engine by a 3/8" rubber hose takeoff. The unit is about a foot from the main fuel line between the FF and VP. I was thinking maybe there was some air that couldn't get out, but can't verify that. Tried changing orientation about a million times, too. I'm thinking of trying an 80 psi sender and just doubling the number or something. I've got a cheap Northern Tool 30psi gauge on the frame rail for double checking my pressure, so I guess that'll have to do until Quadzilla finds a solution.

Qzilla, can you tell us who the manufacturer is that you're trying out?

 

you know it is intresting....i have my needle valve positioned right on the IP...and it is a simple ace hardware 1/8" needle.

i did some testing and actually tried a few things to find out (what i think personally) that it wasnt my unit it was just the pulsing of the IP and fuel coupled with the rattle of the motor and possiblly a ground issue..(ground issue explained later in the post)

i thought that it was the sending unit...(and i will say now..SORRY QUAD, but your customer service is so excelent that i dont think you will care about this) so i had quad replace the unit under warrenty. well i got the idea that it could just be the pulsing and i figured that most everyone running analog was using a needle valve so why not try it with a electric...

i first took off the old one and put the new one on and found that the new one while more steady was still a little on the jumpy side (not nearly as much as the used older one) so i took that one off and added the needle valve at the ip and it soothed it out and gave a good number....then i took that off and put on the old one....that smoothed it out as well...then i tried different locations...i tried the fuel filter both new and old without the needle valve and they were jumpy (new one was better) then i tried the FF with the valve and they both were smooth...then i tried my test guage at the FF and the old one w/ needle valve on the IP and they tested so closley that it wasnt a concern to me...i mean probally with in .5 psi...you know what i mean the needle on the analog test valve was showing 19 or 20 or right inbetween and the commander was the same...so i said screw it...LEAVE THE OLD ONE ON with the NEEDLE VALVE and test it for a week or so...and guess what after a week of testing the needle valve tighting or opening the two guages were spot on...so i left it....now i have a extra sending uint BRAND NEW in the garage.

to tell you the truth, i think it is a combo of a few things....the pulsing of the IP, the rattle of the engine, and what i think may be a bigger issue than most think the GROUNDING of the SENDER...i noticed that when i took the old one off for the 1st time...it seemed almost TOOOOOOOOO easy to back off the nuts holding the ground/sending wire. so i made sure to tighten it back up really good and i plan on checking it every so often.

NCA

 

I realize I'm a new user and all but I do have a suggestion from working on my turbo bike, if anything it throws out another option. bikes rev up pretty quick and coupled to the smaller turbo spooling up fast and having some erratic behaviour during shifts plus boost control compensations I had a lot of pulsing in my fuel pressure readings. What I ended up doing to keep from killing the sending units was to buy a p-clamp with a rubber coating, I think it was originally meant to support 3/4" aluminum tubing, and used it to mount the sender to a solid frame area within a foot or so of my fuel tap. Next, out of a small piece of aluminum stock I made a hose adaptor to go from the larger fuel supply line size down to an 1/8" line, but the trick was to drill only a very small hole through the fitting. Alternately, you could press/epoxy a plug restriction into a fitting you can buy from the local hardware store, might even be able to tap the fitting and screw in a small carburetor jet. By making that hole roughly .060" diameter and leaving at least 4" of hose between the restriction and the sending unit you will get rid of all the pulsing and no more failed senders.

Hope this helps

 

I just quit using the commander for fuel pressure. I use it for rail pressure now. I hooked up a mech fuel pressure instead. I was on my 3rd sending unit.