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View Full Version : Ramjet 350 IAC position @ idle



Kitch
03-18-2024, 09:37 PM
Hi all,

Just a question about "IAC desired motor position" at idle.

I have a RamJet 350 intake manifold on my BP383, running a modified 7427 PCM in my G20 van.
I've noticed my IAC position displayed in TunerPro is about 46 @ 550 RPM in gear.
On a TBI motor I would normally adjust the idle stop screw on the throttle body until the idle counts were around 10 @ 550 RPM.

I haven't been able to find much info on LS style throttle bodies that the Ramjet intake manifold uses but I was wondering if I should adjust it down to around 10 counts at idle, similar to what TBI seems to like?

Cheers,
Andrew

2xls1
03-19-2024, 12:07 AM
On a LS type engine it is pretty accepted to shoot for IAC counts in the 40-60 range fully warmed up in gear.

Kitch
03-19-2024, 12:35 AM
Thanks for that, the one piece of info I found indicated around 40-50.
I wasn't sure if the IAC counts made any difference running on an OBDI 7427 PCM vs the later OBDII PCM that the throttle body would have been designed for.

2xls1
03-19-2024, 04:10 AM
That I don't know. In the LS gen 3 pcms there is an IAC Steps vs Effective area table is calibrated for the size of the IAC passage way. I would say if it is controlling your idle with those steps it is probably working ok. With that combination of parts that was never used together OEM it is going to have to just take some trial and error to see what works best.