I have the quadzilla monitor with the fuel pressure gauge, and smarty jr. Here lately I have noticed my fuel pressure fluctuating alot. Seems to do it just as much if not more at idle, and will drop down to zero and go back up to 10psi at the most. It seems to constantly jump around all over the place no matter how I am driving the truck. Everything I have done to the truck is in my sig. I don't want to burn up my injection pump. Please help, What is the cure?


Thanks in advance

 

First off, double check the fuel pressure with a manual guage. Quad has had a lot of issues with the sender for the fuel pressure. If the manual guage shows the same, then you need to look at replacing the lift pump.

 

Okay, where and how do I check with a manual gauge? Just any diesel shop ? THanks

 

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JONNY:

I would recommend getting another good fuel pressure gauge and checking it against what your Quadzilla Gauge is reading. It may not be your injection pump at all, but in that gauge. Gosh knows I have seen that on my Dodge CTD Pickups.

Also, you may want to try a "Snubber" in the line reading the fuel pressure.
Sometimes, our diesel fuel systems create "spikes" in the systems causing the gauge to read from "high to low" as you describe. You can get these "snubbers" from "Auto Meter", part #3279, and it is called: "Fuel Pressure Snubber." Also, Granger carries them also. These "snubbers" stop those "spikes" and "oscillations" in the fuel pressure lines.

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John_P

 

You can put a manual guage in , right where your sender is for the commander. I have a $20 guage I bought at a parts store. Just look in the tools section for a fuel pressure guage, and most of the time they have adapters and such included in it. Buy a cheap one...you won't use it much, and all you want to do is verify pressure. It really doesn't need to be 100% accurate.

 

I need to do this also. does anyone know what size and threads are on the fitting that goes into the cp3? vzdude did yours come with several different sizes? Also does anyone know if quad is coming out with a better sender?

 

Can't say for sure on the size, but the guage I bought had both metric and standard adapters and one of them fit!

 

Most of those gauges are 1/8th NPT. Off the CP-3 I am not sure sure.
Maybe -3???

 

Alright thanks guys, Like I said it just jumps up and down like crazy. I wouldnt think that it would do that considering all I have is the Smarty Jr. and it acts the same way on the 100hp setting as it does on the 40hp setting. And the fuel pressure doesn't just drop at WOT. It seems to jump around even more at idle and barely cruising. I was beginning to think that I needed to get a fuel system, fass or airdog. I do wish the F****** gauge worked the right way however if its not.


Thanks again, anymore help would be great too!