flat spot

[holden08]

what would cause a flat spot when it idles and you put ya foot down it almost stalls then its ok or when it idles and ya put foot down abit it stalls then its revs at 2000 rpm then drops down back to idle

[holden08]

could it have something to do with the iac valve

[Holden202T]

hesitation to the point of stalling sound like very lean condition to me....

to really know you need a wideband and log to see when it goes lean.

i have been trying to fine tune this issue on my 202 since the rebuild, if i rev it from idle it will be lean and hesitate for a bit then rev, so i have been increasing the AE v's rpm multipiers to get more fuel in where it needs it ...

depends what the situation is though, if the VE table is lean in the spot where its running through that will also effect the AE settings, you want to try and get the VE table pretty close before you do too much AE changes.

[holden08]

ok because it did it with the vn memcal at the same spot and with your tune dunno whats going on it will idle at 700 rpm but give it abit and it will almost stall then when ya take foot off iac open up and hold it at 2000 rpm not for long then drop back down to 700 rpm other than that it seems ok

the light cam on because coolant temp sensor voltage too high and ilde speed error

[Holden202T]

you really need a log to see what its doing but it definately sounds like a flat spot from being lean

[holden08]

the car is unregisterd at moment and just slowly went around the yard coolant temp sensor not working and everything was going up and down in the log

[Jayme]

so are you saying the exact moment you press the pedal it almost stalls then comes good when you let go, or do you rev it and as the revs die down, they die down too far, then the IAC saves it at the last minute, but goes too high and gradually settles back down.
the second scenario sounds more like your throttle stop screw needs screwing in a bit top open up the butterfly more. what IAC steps at idle?

[Holden202T]

well if you can make it play up without driving it then you can get the info you need in a log to fix it, but if your gauges are all over the shop then it sounds like you have an echo setting wrong or something like that, you will need to fix that first before you go too much further.

[holden08]

it idles ok but when i touch the accelerator it starts to stall then comes good it sometimes will stall

[Jayme]

to make it easier, can you record a log of it happening and post it up?