D-Jet Issues-getting close, Need a little more specific advice Options

[BeatNavy]

Mike - I feel like we're having very similar issues with the 2056. Right now on hard decel/overrun I occasionally get the RPM's to drop where the engine will sometimes actually stall. It's very intermittent, which makes it weirder for me. It's no big deal (I just pop the clutch and engine fires back up), but a little disconcerting.

Did you see the thread today about fuel pressure? I'm going to try cranking mine up a notch or two (to 31 psi) as suggested on there. I guess dialing these in to perfect (or good) tune takes some experimenting and time...

Good luck man.

[OU8AVW]

I really feel like the MPS is wrong in my car. The asshats that tuned it for me didn't even have vacuum leaks sorted, plus a few of the hoses were wrong.
Another thing I'm going to sort is the PCV set up. Probably not any real issue but I want to bring the system back to 100% as designed then tune it from there.
I'm making small changes then driving the car so I can monitor each result.

I just installed a new coil too. Another measurable improvement in the way she runs.

[OU8AVW]

Ok, so I'm getting really close.

Valves were adjusted poorly, set them to (almost) zero lash per Raby spec.
New fuel pump with pressure meter installed and adjusted to 29psi (it was at 40!)
Set the new TPS correctly


Please tell me the o2 numbers I'm looking for on my LM2.

I think I'm still a little rich at idle and part load 10.5-12.4
And lean at full load 13.8-15

I saw somewhere that 12.7 was a sweet spot?

Car runs good. Gets a bit lean sounding when I get on it hard and wants to die when I drop RPM for a stop.

[76-914]

A:F ratio, you want to see 13.5-12.9 on the gauge while accelerating or climbing, 12.8-12.5 at WOT, and 16-17 while cruising, going downhill or decelerating.

[OU8AVW]

(IMG:style_emoticons/default/blink.gif)
Ok, I can do that.....

[DRPHIL914]

It wanting to stall or slow idle cold be because it's still running too rich, or timing is still a bit off-i had the same issue(assuming the tps is set correctly). If your numbers are from a warmed up motor, you are rich at idle, part load and lean on wot. I think with air cooled and d-jet motor I would not want to be as lean at cruise as 16-17 as Rich stated. Maybe 13-14. Which is about where i have got mine to. I'm at that 12-13 at w.o.t., idle is about 10.5 cold and 11.5-12 when warmed up, I'd rather be a little on the rich side than on the lean.. I've read the power Is better right at the 13.7-14 . Check your plugs and see how the look , should give you some idea of where you are as well.

[OU8AVW]

After my last adjustment that's about where I am too. Tendency to stall is less now. I saw an adjustment procedure for the decel valve. I'll try that later. 16-17 does seem lean. I'm not finding any consensus on the net about these numbers.

[DRPHIL914]

when i first had my MPS rebuilt then set to factory specs, i had very lean running and even surging at idle , my first corrections were too much and i was very rich, and had that low idle, stall issue. so ive been slowly working it back toward those numbers. Las year at Octeenerfest i was really , under load, too lean and as i accelerated up hill hard it was maybe 15 or so. now its more in that 12.8 range and should run more cool as well when under load. but one factor in my running rich was that i found out that the shop after setting the valves for me did not have the timing set correct. as soon as i set it for the 27'btdc, (they had it set at zero) this put me even more riche and i had to go back and readjust the mps again to lean it back out just a bit. and of course i was running hotter from being too advanced and my idle was too low - now, idle is right at 950 warmed up, it doesnt try to die, running about 10-15 degrees cooler on oil temps and A/F is just about perfect. - it only tooke me 3 years to figure it out, lol!!

[914_teener]

After my last adjustment that's about where I am too. Tendency to stall is less now. I saw an adjustment procedure for the decel valve. I'll try that later. 16-17 does seem lean. I'm not finding any consensus on the net about these numbers.

A bad decel valve can cause similar problems at idle and stalling.

Make sure it is working correctly and not leaking first before you adjust it.

You've done a great job learning the system and doing it yourself. (IMG:style_emoticons/default/beerchug.gif)

[Mblizzard]

when i first had my MPS rebuilt then set to factory specs, i had very lean running and even surging at idle , my first corrections were too much and i was very rich, and had that low idle, stall issue. so ive been slowly working it back toward those numbers. Las year at Octeenerfest i was really , under load, too lean and as i accelerated up hill hard it was maybe 15 or so. now its more in that 12.8 range and should run more cool as well when under load. but one factor in my running rich was that i found out that the shop after setting the valves for me did not have the timing set correct. as soon as i set it for the 27'btdc, (they had it set at zero) this put me even more riche and i had to go back and readjust the mps again to lean it back out just a bit. and of course i was running hotter from being too advanced and my idle was too low - now, idle is right at 950 warmed up, it doesnt try to die, running about 10-15 degrees cooler on oil temps and A/F is just about perfect. - it only tooke me 3 years to figure it out, lol!!

I am going through the exact process. Getting close to getting it sorted but still a bit rich.

[76-914]

It wanting to stall or slow idle cold be because it's still running too rich, or timing is still a bit off-i had the same issue(assuming the tps is set correctly). If your numbers are from a warmed up motor, you are rich at idle, part load and lean on wot. I think with air cooled and d-jet motor I would not want to be as lean at cruise as 16-17 as Rich stated. Maybe 13-14. Which is about where i have got mine to. I'm at that 12-13 at w.o.t., idle is about 10.5 cold and 11.5-12 when warmed up, I'd rather be a little on the rich side than on the lean.. I've read the power Is better right at the 13.7-14 . Check your plugs and see how the look , should give you some idea of where you are as well.

Those numbers I posted are quoted from Jake. But what does he know, right?

[OU8AVW]

It wanting to stall or slow idle cold be because it's still running too rich, or timing is still a bit off-i had the same issue(assuming the tps is set correctly). If your numbers are from a warmed up motor, you are rich at idle, part load and lean on wot. I think with air cooled and d-jet motor I would not want to be as lean at cruise as 16-17 as Rich stated. Maybe 13-14. Which is about where i have got mine to. I'm at that 12-13 at w.o.t., idle is about 10.5 cold and 11.5-12 when warmed up, I'd rather be a little on the rich side than on the lean.. I've read the power Is better right at the 13.7-14 . Check your plugs and see how the look , should give you some idea of where you are as well.

Those numbers I posted are quoted from Jake. But what does he know, right?

Is that waht you're seeing out of your 2056? I'm close to that, maybe 14.5 at cruise. Seems like a 1/8 turn on the inner screw will get me there. Car idels nice at 12.5.

Also, at 8.56:1 compression, should I be running 92 octain? I'm getting some diesling when I tromp it. I've been using 89.....

[DRPHIL914]

It wanting to stall or slow idle cold be because it's still running too rich, or timing is still a bit off-i had the same issue(assuming the tps is set correctly). If your numbers are from a warmed up motor, you are rich at idle, part load and lean on wot. I think with air cooled and d-jet motor I would not want to be as lean at cruise as 16-17 as Rich stated. Maybe 13-14. Which is about where i have got mine to. I'm at that 12-13 at w.o.t., idle is about 10.5 cold and 11.5-12 when warmed up, I'd rather be a little on the rich side than on the lean.. I've read the power Is better right at the 13.7-14 . Check your plugs and see how the look , should give you some idea of where you are as well.

Those numbers I posted are quoted from Jake. But what does he know, right?

(IMG:style_emoticons/default/confused24.gif) (IMG:style_emoticons/default/idea.gif)
Well I can say that I did not see that, I've read a lot of stuff on d-jet and never had any one say to be that lean on cruising. So are we refering to 65 mph @3000rpm crush sing down the highway to be that lean? Sorry but on a 2.0 air cooled motor that just seems too lean but maybe jake can chime in and verify that, and clarify.
I believe you but when I had those numbers it was running hot.

[Dave_Darling]

I believe that Jeff Keyser said that his 914 wasn't happy at cruise until he bumped the mixture up into the 13.5:1 region.

--DD