zkhoss

If I bypass the sending unit and insert insert a needle valve for my fuel pressure gauge can the Di-Pricol gauge handle the diesel fuel?

Also how do I adjust the needle valve?

Stamey

You're talking two different gauges here. If you have a sending unit you have an electical gauge and cannot bypass it, period. If you have a mecahnical gauge you do not have a sending unit, but this type of gauge can have the fuel running right to it, although it is not recommended because, in the case of gas it is highly flammable, and in the case of diesel, it will stink up the truck for a long time if you ever have a spill. You should have an isolator between the mechanical gauge and the fuel pressure feed line.

Chris

Flatty

not again... There is a LOT of discussion on the isolator vs no isolator on this site. I am installing my Di Pricol gauges this weekend with no isolator.

dIma

CTD_Neil

I installed my Di-Pricol pressure gauge with the isolator inline. Overnight the gauge leaked a little on my carpet, thankfully it was glycol instead of diesel. I had missed putting tape on one fitting. Dumb mistake, but it can happen. Had I not used the isolator I would be shampooing still.

Shovelhead

Over 3 years,...... no isolator ..... no leaks.

see this thread:
https://www.dieseltruckresource.com/...458#post647458

zkhoss

My gauge is mechanical. And you are right it is a isolator. The reason I ask about direct fuel is I am having variations in my gauge reading and I think its being caused by the isolator. I know through a second test my lift pump is fine. and besides running diesel to the gauge I dont know what else I can do to stop the variation.

Mopar1973man

Well I just hooked up my fuel pressure guage and it direct to the output of the filter with a needle valve of course.

So far the pump is starting to fail but the needl is smooth to move. Never buzzed, jumped or anything... Just smooth sweep as the fuel pressure rises and falls.

I can't see using a isolator now after setting up the needle valve. If there is a leak turn it off... Not hard... If the isolator diaphram leaks and you get a leak now your screwed...

Just my thought on it.

Shovelhead

Mine too.

ratsun

Well said I agree

jimjawz

I too have a di-pricol fuel pressure guage w/o isolator. I mounted it on my hood like an old school rod. Its so cool, and practical because it has already leaked a tad but its all out side. See my gallery for pics of gauge.

Mopar1973man

What do you expect from me? I learned from the best diesel site and group of diesel nutz!

Once again thanx guys... worship the cummins gods...

Shovelhead

zkhoss

Great info. I am going to get rid of the isolator and go from there. what type, size needle valve do I need?

By the thanx all

Mopar1973man

Napa Store - Weatherhead WH6820 for $5.00 its a 1/8 NPT Female both ends. You might have to have a male / male 1/8 NPT in it to... depends on your design.

zkhoss

Thanks all