K2Cummins

Well I finally finished installing my gauges. Since I have never driven a truck w/ gauges, I have some questions. My EGTs seem normal when I am moving, but when I come to a stop, they go down to 250 degrees. I was wondering if maybe my probe was in too deep or not enough. My other question is about my boost gauge. The needle only moves when I get on it; nothing the rest of the time. Is that normal?

Sorry for the novel and thanks for any help.

dsljunkie

Is your probe pre or post turbo?
Scott

K2Cummins

The probe is pre-turbo. I just thought it was strange that every time I stop it reads 250 deg.

Lil Dog

If you are not working the engine that hard, 250°F is normal for cold idle. Typically mine hover around 300°F most of the time. Its not till you have a long highway drive or do some hard pulls that it will idle around 400° and slowly come down.

Most of the EGT gauges loose some of their accuracy near the bottom of the scale, the voltage is very low from the probe. As long as your probe tip is not contacting any of the manifold metal, you should be OK... The probe should only be 0.3-0.7" in from flush.

J-eh

K2Cummins

I just made a 40 mile drive and going up a hill I hit 850 or so but as soon as I let off the accelerator, it plummeted down to 250 or so. That just doesn't seem right.

Anyone have any thoughts on my boost question?

BigBlue

That's not right. Even on the first start of the day, mine will idle at 300 pre turbo.

As for the boost question. What do you mean by getting on it? Like normal driving or flooring it? You should only see boost when you accelerate or while crusing at higher speeds (I see a couple PSI of boost at about 35-40 mph).

HOHN

It sounds like your probe is not installed properly. It's better to have the probe in a little too far than to have it in not far enough, IMHO. Be careful, though-- if it's in too far, you'll bottom it out and then it won't read right.

If it's not in far enough, the probe isn't exposed to the flowstream.

I will post a pic later if I remember

Justin

K2Cummins

As far as my boost, the needle only really moves when I am on the accelerator pretty hard. I had my comp on 2x5 today and punched it up to 75mph. My boost went from a couple of psi up to 22psi or so then dropped back down to zero once I went over 70mph. Every time it hits the low 20s' psi, it drops back down to nothing.

MLR1

You have a leak or a bad boost guage. You should have about 7 to 10lbs of boost at 70mph.

K2Cummins

I think that I figured out my EGT problems. The probe was threaded in too far; it wasn't touching any metal, but it was threaded in more than it should have been.

HOHN

here's the pic

rattle_rattle

Going down hill, mine will drop to 200!