VX L67 with 69mm TB Cold start stalling

[immortality]

Hi Guys,

I have a small issue, since I fitted my 69mm TB (originally fitted on my old VS) onto the VX it's had trouble with it stalling on a cold start. You have to keep the revs up with the throttle or it dies, once it warms up a little it's fine.

I thought maybe it was a stepper motor problem (although it was fine when on the VS) however after removing it (with the intention of fitting the original stepper motor onto the 69mm TB) I have discovered that the standard VX TB stepper motor has a larger diameter pintle and the passages in the TB seem to be a fair bit bigger as well.

I've come to the conclusion that there is probably a difference in the number of steps used (during a cold start) however these items don't seem to be defined in the VX enhanced tune. At this stage all I can see working is to crack the TB blade open a little and see what happens?

Any ideas or suggests appreciated.

Cheers.

[vlad01]

I noted mace sold VX VY TBs separately to VT and VS ones. this might be the difference I been wondering about.

[The1]

has it got 30-35 IAC steps at idle at running temperature?

[immortality]

Not sure TBH, I just finished cleaning it all up and putting it back together. Gave it another 1/2 turn on the TB blade stop screw but it still stalled when I started it.

I'll take it for a spin shortly to warm it up and then see where things are at.

[immortality]

OK, I have adjusted the idle. From what I can see, warm idle was (originally) about 30 steps. With the extra 1/2 turn it was idling with about 15 steps. I have now adjusted it to 35-38 steps running temp idle.

Took some measurements while I had it all apart. The VX TB stepper motor entry port is 2mm Diameter bigger (10mm Vs 12mm) than the VS. VX exit is a bigger diameter but is is also oblong rather then a round exit and the stepper pintle is about 2mm bigger in diameter as well.

Probably won't know until tomorrow if it's made any difference.

edit: After checking the log I ran, the idle is coming down to about 33 steps

[immortality]

Well, the verdict is in and it isn't good news. The missus says she still had to give it a bit of gas with the pedal for a bit before it would idle, it's not as bad as before but still not right

Problem only occurs when it's started from dead cold, on a warm start the idle is fine straight off the bat.

[delcowizzid]

mace throttlebodies suck for tps voltage v's throttle stop screw position and other things more hassle than good LOL

[immortality]

mace throttlebodies suck for tps voltage v's throttle stop screw position and other things more hassle than good LOL

It was never a problem on the VS.

I think the problem is that the VX has a larger orifice for the stepper motor so you would get more flow with less steps. I think if the VS steps Vs coolant temp table was used it would probably sort the issue. Unfortunately these items aren't defined in the VX xdf.

[VX L67 Getrag]

Post a screeny of the tables, scalars etc you think you need & I will try & add them tomorrow!

If you could link to the XDF your using it would be good too, I'm guessing it's probably $BDb but not sure if enhanced!

[immortality]

I'm using the VX L67 enhanced from The1's enhanced thread.

VX_V6_SC_$A5K enhanced_v1.3.xdf