MicroSquirt.com read only forum (Jan.15,2018)

Today I was able to get the car on the road.
The engine starts fine and idles ok (still need to tweak that one...), get into 1st gear an drive away very gently... It's fine until you reach 1400 RPMs.
Even if you're off the throttle the RPMs will not go back down to 1000 and it gets worse if you hit 2000 RPMs.

I know my VE table is rough, but I don't understand why it the RPMs get stuck.
Find attached today's log and msq, if someone would be nice to take a look and explain what's going on.

From your datalog you are leaning out quite a bit as you approach 1400 rpm. You could try richening up the VE bins around this point. But as far as the rpm being stuck at 2000, I can't imagine this being a tuning problem. I would be looking at the throttle body and the ducting for any air leaks, misalignment, etc. Before you drive on the street you should have your idle and all of the no load range up to several thousand rpm be well tuned and repeatable when you wing the throttle.

grippo wrote:From your datalog you are leaning out quite a bit as you approach 1400 rpm. You could try richening up the VE bins around this point. But as far as the rpm being stuck at 2000, I can't imagine this being a tuning problem. I would be looking at the throttle body and the ducting for any air leaks, misalignment, etc. Before you drive on the street you should have your idle and all of the no load range up to several thousand rpm be well tuned and repeatable when you wing the throttle.

I've noticed the leaning issue. I believe my secondary throttle plates are getting stuck open.
I never had an air leak with the carb on before, I will check but I'm almost certain there's no air leak.
I will do that no load tuning you're talking about.

Again thanks for the help, I will let you know how it goes next week-end.

Fixed.
I have swapped the code for the latest Ms2Extra one and my RPMs are not getting stuck anymore.
It seems that my engine doesn't like something in the 2.888a code.