Surging and low Idle

[wrglrroper]

Hi,
New to Megasquirt and the forum. I installed a MS 3.57 w/MS3X on my 64 Impala. I have a 348 Chevy W motor bored .030 with BWR heads and Edlebrock intake. It has a roller cam with .556/.558 lift, 230/232 duration and 115 LSA. I am running Coil on plug and sequential injection. I have a 92mm throttle body with a stepper IAC. I am running all GM sensors. The problem is my idle surges and jumps between CRANKING and RUNNING. I have tried both locking in my timing and just letting the table work, with no success. i messed around a little with the VE table but when it didn't help I put the numbers back. I think part of my problem is that i don't have any exhaust yet, so I don't have my wideband hooked up. I have it tuned to ignore the AFR though.

Just for information. I have a turbo mounted, but it isn't hooked up yet. Like I said earlier there is no exhaust yet, so I just have the intake piping off for now. I was hoping to get it idling on its own first, then when the exhaust gets on the tuning would go smoother.

I hope I have given enough information. Hopefully someone take a look and help me out.

Thanks,
Richard

[turbo conversion]

If it were me I would get the project completed (turbo iat sensor exhaust o2 sensor etc.) as this will change everything in the tune.

Don't get the cart before the horse, trust me you will regret it

David

[kjones6039]

...............jumps between CRANKING and RUNNING.............

I suspect that lowering Cranking RPM from the current 500 to about 300, should take care of that.

Ken

[wrglrroper]

If it were me I would get the project completed (turbo iat sensor exhaust o2 sensor etc.) as this will change everything in the tune.

Don't get the cart before the horse, trust me you will regret it

David

I am trying not to do that. I figured from what i have been reading getting the idle tuned is most important, and i didn't tink the turbo would change it much. I have an appointment at the exhaust shop on the 15th and i was hoping to be able to idle it onto the lift. If I need to wait it is not a huge deal. It will just literally become the cart before horse, as i will have to be pushing that big boat around. lol

I suspect that lowering Cranking RPM from the current 500 to about 300, should take care of that.

Ken

I thought about that but I was trying to follow the instructions putting it a couple hundred higher. I know this isn't the correct way to do it, but I moved the WUE line way up and that helped keep me. It raised my idle above cranking but it was still surging. I will give that a try though and see what happens.

Richard