Ms1 tuning

[oldschool eighty8]

Grab a log w afr, it could just need fuel tuning.

I'll try to get one tomorrow afternoon.
My wide band is showing 15-17:1 when cruising and high 14's low 15's at WOT. I have a small exhaust leak so I don't know how accurate that is.
Possibly the carbs need to be Sync'd again but I still feel like my ignition table is holding it back.

[need_a_VR6]

Carbs, there's your problem Your WOT afr is leaner then I'd like to see, but I agree that an exhaust leak could be causing issues.

One quick test is run the timing locked at 20-25 and see how it behaves, if it's the same, it's likely a fueling issue.

Also, another quick check is set locked timing and rev the motor and make sure it doesn't drift off of the locked value when checked with a timing light.

[oldschool eighty8]

Yea yea lol Carbs suck but they look good!



I'll give that a try, thanks

[oldschool eighty8]

Got it under control now, thanks for the help everyone.
I ended up adding another 1/2 turn on the mixture screws and backing the advance off a bunch in the upper kpa, might end up taking more above 4000 rpm's. Afr is hanging around 15 at idle an low rpm's. WOT is low 14's feels MUCH happier.

Getting somewhere

[oldschool eighty8]

Bringing this back, sorted out a few mechanical issues so I can really take the car out and mess with it. I'm still having issues with my tune. I've noticed while driving and watching the gauges. As soon as I open the throttle it's going right to the top of the map range. Which making it really hard to tune it for cruising and wot. If I get it so it's not too lean at wot, I'm getting lots of bucking and seeing really lean numbers on the afr gauge when cruising. Any ideas how to cure this?

[ps2375]

What is your plug gap?

[oldschool eighty8]

What is your plug gap?

.038

[ps2375]

Have you tried a smaller gap? That isn't a huge gap, but it seems wider than stock.

[oldschool eighty8]

I haven't, I think stock for a 16v is .032? Worth a shot, I bought two sets of plugs for it. I'm also considering putting the standard knock box ignition in to see if maybe there is an issue with the carbs.

[ps2375]

Well, going lean is def the carbs, but whether that is a very short term transitional lean or the spark blowing out due to being very lean.

Are accel pumps working correctly?

[oldschool eighty8]

R1 carbs dont have accel pumps, I believe the fuel is controlled by the vac ports on top of the carbs. The lean spot is right around 1/2 throttle when cruising. It's also present sitting in neutral reving. What bugs me is how it jumps right to 100 kpa as soon as I open the throttle.

[ps2375]

R What bugs me is how it jumps right to 100 kpa as soon as I open the throttle.

That would not be unusual for injected ITB's, as there is not much volume there and the butterfly will have a huge effect at the slightest change in opening.

[oldschool eighty8]

That would not be unusual for injected ITB's, as there is not much volume there and the butterfly will have a huge effect at the slightest change in opening.

So would I be better off going a different route with the ignition?

[ps2375]

Other than installing a TPS and switching the table from Kpa to TPS, there's not much you can do about the change in vacuum when the throttles are moved. Other than a smaller choke size on the carbs.

And your cams aren't huge, but since they are on an individual runner, extra lift and duration don't help you with vacuum either.

[oldschool eighty8]

I made a quick log but I cant figure out how to post it

also can someone tell me what pin on the ecu plug is input for the wideband?

[ps2375]

Looks like pin 23. Paul is correct, and I can't count. CORRECTED

[need_a_VR6]

O2 is always pin23 unless someone has done a lot of work to make it not!

[oldschool eighty8]

thanks guys
I regapped the plugs , no deal.
I ordered a few different larger main jets today, to help out in the upper throttle area.

Here is my current map. The area I'm getting the miss fire and bucking is in the 2100-3000 area between 100 kpa and 75. Its always run leaner in that spot but started acting up just recently. No matter what I put in there for values it acts the same. I had a similar issue a long time ago with a digi1 car when the grounds on the back of the head for the ecu came loose, doesnt seem to be the case this time.
I'm going to take the carbs apart and inspect the floats next.

[need_a_VR6]

If wildly changing ignition doesn't help, it's likely fuel. I would say add some with the + arrow, but for you it's more work.

Tuning carbs with access to a WB02 is frustrating as you have all the information you need to make changes but they are absurdly hard to implement in comparison to programmable EFI.

[ps2375]

^^^Gotta agree with that. And having never owned a car w/ a carb, I can't imagine converting to them. They do have a place, but currently not in my life or garage. I hope you can make this work out for you and your build. GL

[oldschool eighty8]

Thanks, an I'm not one to give up both the carbs and stand alone are new territory for me, and I've learned a lot about both.

[Prof315]

Tuning carbs with access to a WB02 is frustrating as you have all the information you need to make changes but they are absurdly hard to implement in comparison to programmable EFI.

I would definitely agree there. Bike carbs in particular can be annoying. Weber DCOEs aren't too horrible though.

[oldschool eighty8]

So I picked up a few larger jets to try out, deffinatly made a big difference. I haven't really driven the car a long distance since i got it running till today. It was great for about 10-15 min. Then it started acting up again. So the conclusion I've come to is I think the fuel pump is getting too hot on the firewall and vapor locking. After a few runs the pressure gauge on the regulator is almost at 0 pressure.