• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

What did you do with your GMT400 today...or yesterday....

Visiting Bill H in WA and helping Chris Mursik, my Land Speed racing team owner, prep his Karman Gia for Bonneville. It holds 16 records with various motors to include 1/2 VW (2 pistons removed). This week we’re kinda playing musical chairs with engines and such. Pull a front end and transmission/driveline out of a dune buggy. Pull an engine from a Bug street racer, pull the current engine (2 cylinders) out of the Gia, Switcheroo the gooder parts into the Gia.
View attachment 94773
View attachment 94772
This morning I realized I needed an oil change and had a moment to get after it. While under there I think I may have found one of the sources for the rattle noises I get from the front when driving over road imperfections.
View attachment 94774

Good thing the bolt didn’t hit anything important or do any damage. Oh wait….
Half the shock mount snapped off because the bolt got caught up in…
View attachment 94775

…the CV joint!
View attachment 94776

Thankfully, Chris is a car fabricator and industrial welder so he fabbed up a replacement shock mount and had it repaired in short order.
View attachment 94781

Looks good. Better than new.
View attachment 94779
That Ghia is like going back in time for me. I started my DIY mechanic career on air cooled VW engines. Are those dual Weber carburetors? Where’s the turbo?
 
What I did with My GMT400 today, destroyed another injection pump or some such.
Whatever this means ? ? ? ?
View attachment 94795

A P0251 code on a 6.5L diesel engine typically indicates a problem with the fuel injection pump's optical sensor or camshaft position sensor circuit. This sensor, which reads the rotation of the injection pump's main shaft, is crucial for determining fuel injection timing. A faulty sensor, wiring issues, or air in the fuel system can trigger this code.
 
I’m happy to report that the front end rattle is gone….

Truck is loaded up for the return trip. Heading home in the morning. I’ve got two engines I’ll be dropping off to other race teams on the way home. One is another VW for a fellow Gia driver. The other is an inline Ford unit going to a family with a long history of land speed racing (the 4th Generation is now driving). It’s a gift for the grandfather who’s dad used to run the same motor “way back when.” His kids will put it into their Streamliner without his knowledge and surprise him greatly. I’ll be dropping both of them off Sunday in Ogden before I get home.
 

A P0251 code on a 6.5L diesel engine typically indicates a problem with the fuel injection pump's optical sensor or camshaft position sensor circuit. This sensor, which reads the rotation of the injection pump's main shaft, is crucial for determining fuel injection timing. A faulty sensor, wiring issues, or air in the fuel system can trigger this code.
I popped that code the other day. It launched the Service Engine Soon light but, self cleared. I checked codes and wrote it down and will see if it comes up again. It’s been over three weeks now and no instances. Normally I fill at Sinclair stations so I chalked it up to fuel as I had filled up at a Maverick and their fuel is the low cetaine (sp) bulk stuff that isn’t the best.
 

A P0251 code on a 6.5L diesel engine typically indicates a problem with the fuel injection pump's optical sensor or camshaft position sensor circuit. This sensor, which reads the rotation of the injection pump's main shaft, is crucial for determining fuel injection timing. A faulty sensor, wiring issues, or air in the fuel system can trigger this code.

I popped that code the other day. It launched the Service Engine Soon light but, self cleared. I checked codes and wrote it down and will see if it comes up again. It’s been over three weeks now and no instances. Normally I fill at Sinclair stations so I chalked it up to fuel as I had filled up at a Maverick and their fuel is the low cetaine (sp) bulk stuff that isn’t the best.
I had fueled at the CENEX Zip Trip and mistakenly filled with their regular run of the mill diesel that most people fill up with, instead of their RoadMaster blend.
I did add about a pint of TC-W3 two stroke oil plus about enough Stanadyne Performance Formula supplement to make up for the estimated 20 gallons to fill the tank.
 
I had fueled at the CENEX Zip Trip and mistakenly filled with their regular run of the mill diesel that most people fill up with, instead of their RoadMaster blend.
I did add about a pint of TC-W3 two stroke oil plus about enough Stanadyne Performance Formula supplement to make up for the estimated 20 gallons to fill the tank.
What diesel additives do you use every tank fill?

I use Clear-Diesel, Hotshots, Optilube XPD, John Deere & Power Service Gray in the summer - white in the winter.

I'm not too picky. Whatever I find when I'm looking.

For anything going in a can or storage I add some bug killer.




 
Last edited:
As an Amazon Associate we earn from qualifying purchases.
The dye in the 2 stroke oil may be your issue
Does this look too dark ?
IMG_3579.jpeg
The previous refueling took about 20 gallons. I did not add any two stroke to that tank of fuel. The last refueling I added about a pint of two stroke, that was about another 20 gallons.
And it was on this tank that the code about the optic sensor tripped.
What diesel additives do you use every tank fill?

I use Clear-Diesel, Hotshots, Optilube XPD, John Deere & Power Service Gray in the summer - white in the winter.

I'm not too picky. Whatever I find when I'm looking.

For anything going in a can or storage I add some bug killer.




This is the two stroke that I have been using.
IMG_3582.jpeg

And this is the fuel supplement.
IMG_3581.jpeg

I keep the additive in a bottle that services about 60 gallons and estimate how many gallons it will take to fill the tank and if I think it will be about 18 gallons I’ll add about a half a jug of the supplement.
Maybe I better hold off on the two stroke for several fuelings and get the color diluted down.
Also, this P0251 code never did trip even with the leaking remanufactured injection pump, nor with the previous pump that was sucking air, or, with the original pump that was on the original engine.
It didnt trip for about 30 or 40 miles, not until I was near 20 miles out did the engine stumble slightly but then run as normal until I made it another five miles after pulling over to diagnose the SES lamp.
 
Last edited:
As an Amazon Associate we earn from qualifying purchases.
A picture of the container hanging in a little more light.

IMG_3583.jpeg
IMG_3584.jpeg

Now letting that pail of fuel from the T fitting set to determine if there is bio diesel present.
If there is ANY amount of bio stuff will it separate out and settle in the bottom of the pail ?
One thing I did see was quite a bit of air coming through when obtaining this pail of fuel.
It did clear up so now I’ll be warming the engine again and seeing if it now still cuts out.
Maybe after I know the neighbors are up and attum. 🫣😹😹😹
 
A picture of the container hanging in a little more light.

View attachment 94961
View attachment 94962

Now letting that pail of fuel from the T fitting set to determine if there is bio diesel present.
If there is ANY amount of bio stuff will it separate out and settle in the bottom of the pail ?
One thing I did see was quite a bit of air coming through when obtaining this pail of fuel.
It did clear up so now I’ll be warming the engine again and seeing if it now still cuts out.
Maybe after I know the neighbors are up and attum. 🫣😹😹😹
Do you bleed the T valve when you bleed everything else?

I always have. Unnecessary or not.

I've sometimes experienced improvement just as a result of draining the T valve
 
I installed the momentary switch from the Leroy Diesel lift pump harness into the relay and pump wire onto the Air Dog system.
Now I can turn on the lift pump from under the hood and bleed the filters and drain the T-Valve without having to turn on the ignition switch from in the cab.
Got that all back together and the engine has not improved in the way it is running.
About out of ideas except to install the intake manifold and see if that changes anything.
 
Tried switching pump drivers with no improvement.
I’m at a loss other than installing the original lift pump back onto the engine, I know it was properly functioning except the advance stepper motor shaft was seized up.
Or else install the intake manifold and see if that makes a difference.
I’m just at a total loss on this one.
 
A picture of the container hanging in a little more light.

View attachment 94961
View attachment 94962

Now letting that pail of fuel from the T fitting set to determine if there is bio diesel present.
If there is ANY amount of bio stuff will it separate out and settle in the bottom of the pail ?
One thing I did see was quite a bit of air coming through when obtaining this pail of fuel.
It did clear up so now I’ll be warming the engine again and seeing if it now still cuts out.
Maybe after I know the neighbors are up and attum. 🫣😹😹😹
The two stroke dye won’t cause any issues. I’ve run it many times. Red dye diesel also will not cause issues.
 
Back
Top