im new to the diesel world, i just bought a 96 cummins, im curious to wat my boost egt and tranny temp gauges should read, it does have a fuel pressure gauge that the previous owner unhooked due to rapid fluctuation, why would it do that, i cant tell you all the mods done to the truck but it does have 5k govenor springs, does that affect the fuel pressure, thanks dave

 

Welcome to DB...

Moved this to the 12v cummins forum so it should get a little more traffic.

 

ur fuel pressure shouldn't fluctuate far as i know. keep your egt's under 1250 and boost under forty pounds and you should be good.

 

The gauge is going crazy because of pulses from the pump. You'll need to put a needle valve in the gauge line to smooth it out. I heard of another way of doing it, but I can't remember anything today.

 

Hey quick question. I see a lot people installing fuel pressure gauges? What's the purpose? i'm planning a p pump swap on my 1st gen. and i wan't to get all my gauges in line, want to know if i'm gonna need one or not. thanks!

 

A fuel pressure gauge isn't necessary for a p-pump, but it does go a long way in helping to diagnose problems when they arise. Also helps you keep an eye on the condition of your fuel filter.

I know Autometer sells a fuel pressure line snubber you can put inline with your gauge to stop those pulsations, but like tater said, a needle valve will work just as well.

As far as trans temp gauge, mine hardly ever goes above 140-150 (in the pan). As far as an upper limit, I'm not sure of an exact number, but if it gets up around 200, I'd start keeping an eye on it.

 

200* and auto trannys start melting on the inside

 

Hey thanks for clearing that up for me. I'm an over-the-road diesel mechanic, so I don't do many performance mods, but I couldn't think of any other reasons than that for a fuel pressure gauge. Thanks!