I did a search and found a picture showing where to tap into for a boost gauge. If I have it correctly, its an 1/8" NPT bolt with a 7/16" head that is right inbetween the 4th and 5th injectors? I have taken that plug out and used an 1/8" NPT fitting with plastic tubing going to an autometer boost/vacuum gauge. Start motor, gauge doesn't move. Disconnect gauge from tubing and there is no vacuum from that port. Am I retarded? Can someone help?

Pic is here https://www.dieseltruckresource.com/...=install+boost

 

The place to tap in is located right behind the injection pump in the air intake manifold as shown in the diagram in the link. This will be just a little to the right of the overflow valve on the injection pump as you look at the drivers side of the engine. Take out the plug and insert your fitting. You will see no boost pressure at idle - have to have a little load on the engine to get the turbo spooling to make boost.

John (DH)

 

Yes, I took that plug out. There is no vacuum at idle. Is that how a diesel runs? No vacuum? Please help me out, is my engine a fluke?!?!

 

Wait a minute, does this port only provide boost, and not vacuum? It does say pressure port in the pic. Can someone verify that only boost comes out of that port and not vacuum? That does not make much sense to me. I have not tried to drive with the gauge hooked up, but the engine will run and idle with that plug removed and nothing in its place.

 

Even at an idle your turbo supplies enough charge air to eliminate vacuum in the intake manifold. I could guess you would see a vacuum at that port if you disconnected your turbo supply boot, but I've never tried it.

 

Boost = Pressure. Positive pressure. No Vacuum. Git in it with the gauge hooked up and get on it and you will see boost when the turbo spools.

John (DH)

 

there is no vacuum on a diesel engine so 0 pressure is a good thing at idle. just get a 0-60 boost gauge.

 

Rats, you beat me to it. I was going to tell him the best place to mount the vacuum fitting was just below the throttle plate on the carburetor

 

Yeah I'm retarded. This is my first diesel so ***. My gauge only goes up to 20psi. I only hit 15psi then shut it off, what is the stock max boost? I heard it was 19psi?

 

18-19 sounds about right but the sooner that changes the better. grind your fuel plate and get a boost elbow once you get the right boost gauge, star wheel adjustment too for throttle response and a little smoke. then youll be askin "is this the same truck?". have fun my friend. if you cant be good, be careful.

 

Ok, next mod will be a pyro. Then a GSK.

One LAST question, what is the stock max rpm? I seem to only to be able to get to about 2300rpm, bone stock. I can't get anywhere near redline on the stock tach.

 

A 3k GSK will get you to 32 or 33 hundred. Until you change to 60 lb valve springs you don't want to get much past that.

Gauges first!!

 

Ok I peg the **** out of the 20psi gauge, and I know its got alot more.

Just put in valvoline 15w40 fleet C rated oil and napa gold filter (wix).

Next thing is a pyrometer, but I am still worried about metal shavings...

And is there a direct correlation between EGT and engine oil temp?

Any clue on max stock rpm?

 

I can peg the tack with my 4K gsk kit and HD springs and it has a lot still to go.

 

I'm asking what can the stock cummins rev to without a GSK, is there something wrong if I can't rev past 2300rpm?

I've searched for days and can't find it, I actually crashed the server, it sent me a message to try later!