Another ITB build thread

[grelland]

yes 1/2 teed, then 3/4.

The PW is in the ballpark, as the engine runs, but it stutters quite a bit off idle, and I hear the occational pops, so it is far from good...

[Devastator]

I had a noisy MAP signal, so I made a reservoir that smoothed it out unbelievably. I took a 3/4 PVC nipple about 2" long and capped both ends. Drilled and tapped these ends and installed 1/8" barbed fittings. Put this inline before the MS MAP sensor, and viola!
Worked for me.

[Steve Arndt]

your MAP signal is a bit noisier then mine. How did you gang your vac lines together. I have 1/2 tee'd together and 3/4 tee'd, then each bank is tee'd to MS.

Looks like there is a setting wrong or something for your wideband, the PW looks to be in the ballpark.

Running my four vacuum lines to a healthy size vacuum manifold made a huge difference. I also run a .026" restrictor right before the sensor. It is a cheap thing to test out. I built the manifold out of 3/4" PVC pipe, 4 inchs long, capped. Then I drilled it and JB welded 3/16 drip line irrigation barbs for fittings. It works great, and cost under 2$ to build. I sanded it smooth where the JB was messy, and painted it flat black.

s

[grelland]

Thanks, will do something like that

Another question for you guys, I posted it in the Megasquirt section:
viewtopic.php?f=66&t=139324

Roy

[grelland]

Hmmm noone knows this?

Oh well.

I am still struggeling with my LC-1, and until I get that fixed, I though I should adjust the mixture at low rpm a little, so that is is a bit more driveable.

I expect I am way too rich, as it shoots flames out of the exhaust when I step off the gas. Is that correct? It picks up well at higher rpm, but stutters a bit off idle.

any pointers?

[andy198712]

The exhaust is all completely sealed yh?

[roachdogg28]

It sounds like its pretty rich, but like andy said could be leaks also. When i was fabbing my header, i wanted a preview of how it would sound while it was just tacked together w/o the o2 sensor in... Needless to say, i lost some leg hair. About a 2-3 foot flame, and sounded like a 10gauge shotgun in my garage.

[grelland]

Thanks, I tried leaning it out a little and it was definately a move in the right direction, but I will not bother until I have the LC-1 up and running again.

I will also check for leaks.

So nobody knows what the engine bits 7 and 8 does???

I will post a question on the MSextra forum, there is probably someone there that knows

[Piledriver]

I want to say accel/decel (can be triggered by MAP noise) but my brain is jello right now.

Crank your AE treshold up to 400 or something and see if it goes away.

The latest firmwares MAP averaging worked wonders for me, but I don't have ITBs.

[Devastator]

I want to say accel/decel (can be triggered by MAP noise)

Absolutely.

[grelland]

thanks guys, that would make sense based on my observations. I will have a closer look later tonight.

What is the latest firmware you are using, Piledriver? I am running MSextra.

[Piledriver]

ms2-extra 3.3a3.

User gslender from Oz has been doing some excellent work adding features, so far mostly idle enhancements that seem to work beautifully.,, his latest is (EDIT-245), based on 3.3b2. If you want a rock steady idle and can't get it with the std code, try that by all means. (even if using only advance for idle speed control, it has improvements)

The latest official builds include a much improved firmware loader as well, use that in any case.

[grelland]

Thanks a lot, I will dig into that,

Meanwhile, I tried your suggestion of increasing the MAPdot threshold to 400 on the AE settings, and at least the oscilllations on Gammae disappeared, and it ran a LOT better.

This indicates quite strongly to me that the MAP fluctuation is the root cause, and I will make myself a smal reservoir.

Thanks a million for the tip

Here's a screendump of a log I did earlier tonight:

graph.png

[grelland]

crappy sound, but it runs as smootly as ever on idle. 7-800 rpm, dead stable, and this is even before I touched the mapping


https://www.facebook.com/video/video.ph ... 0978943133

[supaninja]

crappy sound, but it runs as smootly as ever on idle. 7-800 rpm, dead stable, and this is even before I touched the mapping


https://www.facebook.com/video/video.ph ... 0978943133

I hate you Roy , that thing is idling nice