Turning Fuel Up on a "G Code" Injection Pump - Video

[HanksDeuce]

I put together a video on turning the fuel up on a M35A2 equipped with a "G Code" injection pump. This type of pump doesn't have a FDC (fuel density compensator) that is adjusted on the outside. Instead, a cover is removed over the governor and 2 nuts are adjusted between a bridge plate that is next to the stop plate and smoke cam.

Enjoy! Let me know if you have any comments.

Moderators: I think this thread is a standalone (STICKY) because it is a video and not turning fuel up in pictures. The majority of the turn fuel up in pictures thread is about adjusting the FDC equipped pumps anyway. Feel free to merge if you disagree.

http://youtu.be/XChF3rMT348

 

[barefootin]

Subscribed just incase it doesn't become a sticky....

 

[JasonS]

Nicely done.

 

[HanksDeuce]

Anybody else adjusted one of these pumps? My truck seems to be a 1 psi boost gain per flat on the jam nuts. I'm continuing to make adjustments, so 5-6 flats should get me 12 psi. It's raining today, but 4 flats have helped me get to 10 psi and well below 1200F.

 

[doghead]

Consider that you are adjusting and testing with no load.

Loaded, you will get you higher temps.

btw, do you have bionic hands or did you speed up the video?

 

[HanksDeuce]

I don't follow you on the no load comment. Are you talking about towing a trailer or going up steep grades?

I sped up the video during disassembly and reassembly because it would have made the video that much longer.

 

[doghead]

Are you talking about towing a trailer or going up steep grades?

Yes, either will increase your egt.

 

[HanksDeuce]

Fortunately for me there are no steep grades around here other than the Mississippi River bridge. My test loop consists of long interstate runs including many long overpasses, city traffic, and a 4-lane highway with a 65mph speed limit. No issues whatsoever with load. I don't tow anything with my deuce so I'm good on that end as well.

No chance at making it a sticky?

 

[HanksDeuce]

Bump to the top near sticky threads.

 

[welldigger]

Honestly I will second the idea of making this a sticky. I love "how to" videos on a common problem/question. And I happen to have this style of IP.

 

[HanksDeuce]

This injection pump adjusting is getting confusing to say the least.

So far I've adjusted the jam nuts to 1 full turn (8 flats) + 2 more flats. This got me to 10-11psi max, 950F max EGT. The truck is responding very well to the new fuel. I can now keep up with traffic pretty well. The adjustments will continue until I start to inch closer to 1200F and whatever boost I can get.

 

[HanksDeuce]

Bump to the top for others to see.

 

[HanksDeuce]

This time I'm bumping the thread to the top to check on something...

What's the most boost pressure you guys run on a M35A2 with a C turbo (aka whistler) when you turn your G Code pump up? Although I'm at 11psi right now and never hitting above 1100F on the EGT, I'm going to bump the fuel tomorrow to see if I can inch closer to 1200F. Tom at Waterloo Specialties mentioned in another thread 14psi is achievable on some trucks in a safe manner while keeping EGT readings below the magic 1200F. There was that one crazy loon that got 22psi or so he told us. I'm skeptical on that one for sure unless I see video or the truck in person.

 

[welldigger]

Are you not happy with the power output? On a good hill climb or towing I'd imagine it would climb right on up to 1200.

 

[dangeroustyz]

Kinda new to the game. How can I tell if I got a " g code pump"? I got a 71 white multifuel. Thanks

 

[Floridianson]

It's nice to see vids. The problem with road tests is producing the same load everytime when you realy can't control the load the same everytime on the road. Find the TM troubleshooting the 465 and there it will tell you in detail how to perform the load test useing the brake peddel to produce load for the test. You will need two people as it's hard to read the boost gage and be trying to watch the tac every second while trying to keep throttel and brakes played with to hold the rpm's correct. That or find a truck Dyno to produce the same load everytime.

 

[HanksDeuce]

Kinda new to the game. How can I tell if I got a " g code pump"? I got a 71 white multifuel. Thanks

Does your fuel pump look like mine in the video? If it does, it's a "G Code".

 

[Squirt-Truck]

The manual calls for loading the truck by applying brakes and pulling the RPM down to 2400 for full load testing. Curious just what EGT and boost you get at full load.
Is the EGT pre or post turbine?

 

[HanksDeuce]

The EGT is pre-turbine in the exhaust manifold. I need to read the manual further. I'm not following the procedure you speak of (and has been mentioned before). Do I apply the brakes while driving down the road and hold the RPM at 2400? Things get busy at 2400 in 4th with 53's.

 

[HanksDeuce]

Yet another ploy at getting this thread to become a sticky. No love from the moderator(s)?