Pump Adjustment Theory

R.Mojica · #1 04-03-2017, 05:11 AM

sounds like its time to get those GTD nozzles.

adamdrives · #2 04-15-2017, 02:00 PM

After following anders directions the car is way less smoky (still smokes a little, hill start in 1st or winding up second will leave a decent cloud) and doesn't feel down on power. Got 28 mpg my last highway trip over 150 miles going 70-75 the whole time in 65 deg weather. Not sure why people recommend adjusting that limiter downwards for performance, all it does is add smoke. Has anyone here tried the governor mod? Shimming the springs or adding a stiffer spring? I would still like more power down low. Contrary to what everyone says about diesels and their low end torque, this car feels most powerful on the highway from 4k onwards.

ngoma · #3 04-17-2017, 03:54 PM

Quote:

Originally Posted by adamdrives

Has anyone here tried the governor mod?

See this post Governor mod. A Simple search brought that up.

adamdrives · #4 04-17-2017, 04:20 PM

Thanks, I believe I have read that one, it's just very short and I was hoping to get more than one impression.

anders · #5 04-18-2017, 04:48 AM

Quote:

Originally Posted by adamdrives

After following anders directions the car is way less smoky (still smokes a little, hill start in 1st or winding up second will leave a decent cloud) and doesn't feel down on power. Got 28 mpg my last highway trip over 150 miles going 70-75 the whole time in 65 deg weather. Not sure why people recommend adjusting that limiter downwards for performance, all it does is add smoke. Has anyone here tried the governor mod? Shimming the springs or adding a stiffer spring? I would still like more power down low. Contrary to what everyone says about diesels and their low end torque, this car feels most powerful on the highway from 4k onwards.

That's good news, sounds like there might be some more things to take care of if your still getting smoke upon hard acceleration. A slight haze is fine and helps the turbo spool up faster. I have done the governor mod, it was a nice easy mod that helped raise the power band. These engines do produce there power up top, it's the way it was designed, to have similar chartaristics as a gas engine. You can't get much power below 2000 rpm, I think peak torque is at 2800 rpm on these. The NA intake seems to help with the lower end.

woodfordhalse · #6 04-19-2017, 07:19 AM

Hi
Sorry to hijack your thread but after adjusting the smoke screw with the lda unscrewed completely am i correct in assuming you then screw the lda back in for less smoke , as much power as possible ratio...

Cheers

anders · #7 04-19-2017, 10:04 AM

The adjustment screw on top of the LDA adjusts the pre-boost fueling. Threading the screw in provides more off boost fueling (smoke) threading it out provides less off boost fueling (less smoke).

adamdrives · #8 04-23-2017, 09:46 AM

Quote:

Originally Posted by anders

That's good news, sounds like there might be some more things to take care of if your still getting smoke upon hard acceleration. A slight haze is fine and helps the turbo spool up faster. I have done the governor mod, it was a nice easy mod that helped raise the power band. These engines do produce there power up top, it's the way it was designed, to have similar chartaristics as a gas engine. You can't get much power below 2000 rpm, I think peak torque is at 2800 rpm on these. The NA intake seems to help with the lower end.

If I pin it in first without easing on the throttle for first few moments, I'll leave a pretty healthy cloud, but that seems to be the worst of it. I believe I backed off on the LDA as much as possible but I will re-investigate. Going more than a third throttle or so in 2nd and 3rd below 2k (especially when cold) will also leave some light grey haze behind me. My eventual goal is to have it be smoke free, but I'm satisfied by the improvement for now. First gear smoke is annoying as I live in a hilly area and getting moving from a light inevitably leaves some haze behind me. Ideally I would like to be able to drive it without having to compromise power for smoke in some situations.

adamdrives · #9 04-23-2017, 11:17 AM

I fixed the throttle so now I am hitting the fast idle screw at full throttle, not the stop on throttle spool, that seems to have helped pick up a bit. Definitely a good thing to check. My throttle cable is still about half an inch too long, I can't get all the slack out of it. I guess they stretch over time. I was able to back out the LDA more but that hasn't affected smoke, I guess it was at it's practical limit already.

I believe peak torque is 2500, that probably changes with a non-stock turbo. I am curious to learn more about this governor mod, but am intimidated by taking my pump apart. On a scale of difficulty how would you rate it? Do you follow any guide or do you know what to do from experience.

ngoma · #10 04-23-2017, 12:23 PM

Quote:

Originally Posted by adamdrives

My eventual goal is to have it be smoke free...

Hey it's a diesel from the mid -80's, the design originated in the mid -70's. It's always going to emit some smoke. Not billowing black clouds, but some smoke now and then is part of the package.