Tuning with no speed sensor

[jca]

Hi guys, does any body have any tips on getting some sort of idle control with no speed sensor input, I know it would be heaps better with a speed sensor it has a h286 cam idle perfect one minuate and then iac starts to hunt.

[Holden202T]

got a log of it ?

is it hunting only after a drive or even before moving the car ?

[jca]

Hi, yep its after a drive to pulling up at interceptions etc, I've been trying to get me aldl cable to work but i don't think the serial to usb cable likes my laptop with windows seven?

[VX L67 Getrag]

I Have mine working in win7 fine, you sure you don't have real time stuff enabled?

[antus]

Do you have an FTDI chipset cable? You'll need one of those. If its prolific brand they dont work, although there is a registry hack around on the forums somewhere that will make some of them do whats needed. It didnt work on mine, though.

As you note the stall is due to no speed sensor. The ecu cant tell when its moving and idling, and thats the result. You could try adjusting the throttle stop screw a little to let a little more air through always, or get a speed sensor fitted. Im not sure if disconnecting the IAC would help.. Jayme?

[Holden202T]

disconnecting the IAC would stop it from doing it, but you'd probably be better off leaving the IAC connected and just open up the butterfly so it can never stall, even if you just get the idle at 5 iac steps or something, so when the iac goes to zero it will be like 50rpm below desired idle, but then the IAC will still do all its stuff in the cold start environment etc.

[Jayme]

exactly... ive got 3 cars running like that, just wait till its warm, then wind the stop screw in till you are at 0 IAC steps. that way when its cold, the IAC can still open and keep the idle up. when you are slowing to an intersection it will close the IAC to 0 but it wont matter.

[Doctor Bob]

can you force open loop idle?

[VL400]

There is no flag as such but might be able to use the deadband settings to force it not to make any closed loop changes to the IAC steps. But it would stay at the base settings so idle might be high until you adjust the throttle stop screw a bit. Its prob easier to just do the 0 steps that Jayme sugested though, proven to work

[jca]

Hi, when u say set the idle control to 5steps are u meaning in the tune or by the throttle stop? or both?, i have the stop screw backed off as far as possable and i drilled a 3.5mm hole in the blade so i ve got the steps down to around 30 which i think is sett in the tune? (will check when i'm on my other pc), i don't seen to be able to get tps to 0% its around 3-4% so might try another switch, it is also fouling the plugs while cold i've got another tune from rob so i will have a play today , its annoying ive tuned this cam heaps and never had this much trouble. the aldl cable i'm using was off ebay i reckon 5years ago so ive only used it with winadldl not tuner pro can some provide a link to what there using or can i make a better one. thanks