Last spring I installed a Dipricol 30PSI electric fuel pressure gauge on my 98.5 24v 5.9, to monitor the lift pump pressure and try to avoid munching the injector pump. It worked fine, showed me 10-15 PSI under all operating conditions, lower under load, higher at idle, just like you'd expect.

Today I noticed that it was pegged at 30PSI. I didn't think the lift pump could make that much pressure! I cycled the power, the gauge reset to zero (like always), then climbed right back to 30PSI -- with the engine stopped and the lift pump not running. I even opened the water drain on the fuel filter housing (where the sender is mounted) to make sure there wasn't any pressure in there, but it's still stuck at 30.

When I disconnect the sender wire, the gauge drops back to zero; plug it back in, up to 30 again.

What do we think -- bad gauge or bad sender? Any other tests I can run? I contacted the shop I bought it from (waiting to hear back), but they don't even carry Dipricol anymore. I don't think Dipricol even makes electric FP gauges anymore.

Could the sender have been damaged by pressure pulses? I thought that was only a problem for mechanical gauges....

 

Bad sender.
If the sender is connected directly to the engine the vibration will kill it.
Best to isolate the sender from the engine with some hose to the fender or firewall.

 

Screwed directly into the engine-mounted fuel filter housing, so yeah. I'll do it right next time.

The question now being, since my gauge manufacturer seems to have gone out of business, where do I start looking for a replacement sender? I have the part in my hand, it's a 3-wire sender for a 0-30 PSI gauge, 1/8" NPT, numbered C630P022, 0100GUYB2 and BJ73A. A google search turns up very little. I guess I'll haul it to a couple of local diesel shops and see if they recognize it as common or as a rare bird. I really don't want to shell out $200+ for a new gauge kit...

 

Very surprised to hear DiPricol has gone out of business, they were one of the top gauge manufacturers.
Their gauges are OEM on various Cat, Komatsu, and John Deere products.

These guys should be able to help you www.puredieselpower.com

 

I dont think they went out of business. They scaled down and are concentrating mainly on the OEM side. Email Danin and see what they say.

info@danininc.com

 

Ah, turns out they AREN'T out of business, they just quit making my gauge, don't answer email, haven't updated their web page in years, and my vendor gave me a wrong, out-of-service phone number for them.

Good news, they can sell me a new sender. Bad news, it's like $100 or so, half the cost of a whole new gauge kit. Still relatively cheap insurance for my injector pump, but dang...

 

You could have bought a mechanical gauge for under $100 then never have to deal with a sender again...

Thing I don't like about electric gauges is sometimes when the sender fails they lie to you reading only 0 and the highest number they have ever seen with nothing inbetween. Makes you think your pressure is fine when it really isn't.
What good is a gauge you can't trust?

 

Amen, brother. When I install my pillar pod, I'm switching to a mechanical gauge. My electric gauge has had some strange issues that leave me wandering if I really have a issue or if there's a problem with the gauge. I've seen weak batteries screw with the gauge. I also have an issue in the winter months where the guage will sometimes bounce around from 0 - 20, but it never does this during the hotter months. I don't trust this gauge!