IAC counts high

[Schurkey]

I had it adjusted to 10 counts at idle and 70 in gear. What do you think went wrong?

Adjust it according to the service manual.

Nearly every time someone messes with the base idle screw, they have problems with idle speed, IAC operation, or sticking throttle blades until that screw goes right back to where it was.

Yes, of course verify lack of vacuum leaks, PCV operation, general engine health and "tune-up" parts/services, and so forth.

 

[dhworkin]

Which side is map on ?

Back side facing the firewall

 

[dhworkin]

Adjust it according to the service manual.

Nearly every time someone messes with the base idle screw, they have problems with idle speed, IAC operation, or sticking throttle blades until that screw goes right back to where it was.

Yes, of course verify lack of vacuum leaks, PCV operation, general engine health and "tune-up" parts/services, and so forth.

My Rochester 220 was purchased from SPR performance and that blade adjusting screw was not easy to get right until tuner pro 5 and a laptop. After the map sensor change I was able to set IAC counts to 10 at idle so that is working as it should. I’ll check the PCV port for vacuum and get back with that number. Thank you

 

[dhworkin]

PCV port read 17. Motor has a lunati 20080660 cam. I changed the PCV valve and the rattle stopped. I put vacuum on both valves and the old on needed more to open plus it had more side to side play. It’s driving better than it ever has, but the hesitation/lean condition when accelerating has always been a problem. With timing at 0 it is terrible, timing at 10 btdc not good and at 14 btdc it’s almost gone. I’m have no knock counts and it starts easy when hot so I’m going to 16 next, is that normal? Timing is set mechanically and in the calibration with EST disconnect.

 

[Scooterwrench]

That cam shouldn't need that much initial timing. Have you checked your bypass connector to see if it's making a good connection?

 

[docstoy]

How many teeth on cam gear ? Could be a tooth off.

 

[Scooterwrench]

How many teeth on cam gear ? Could be a tooth off.

Hmm,I've installed dozens and never counted the teeth. It's 2:1,that I know. Easiest way to find that out is buy a degree tape and put it on your harmonic balancer then a dial indicator on tip of the #1 intake rocker and see if the valve opening matches the cam card.

 

[docstoy]

36 on cam gear, that's 10 degrees

 

[Scooterwrench]

36 on cam gear, that's 10 degrees

20 on the crank.

 

[dhworkin]

That cam shouldn't need that much initial timing. Have you checked your bypass connector to see if it's making a good connection?

Connection is good