EFIDynoTuning Forum

Believe I have an issue from heat soak from the turbo goodies under the hood. With startup enrichment dialed in it will restart lean and stumbly after it’s been sitting for an hour or so after being ran. If I add enough fuel to combat that it seems to overshoot rpm’s when it’s not heat soaked with the higher act’s. Is there anything else I can look at to try to tune around this?

if it starts lean after startup then startup enrichment isnt dialed in

if the added fuel raises the rpms then that means the engine wants it

sounds like everything is functioning perfectly

It only restarts lean after it sits for a bit, say stopping at a restaurant for a bite to eat. If I restart immediately like right after fueling up it’s fine. Then when it’s not heat soaked the extra fuel makes it rev higher then dsdrpm which annoys me for some reason. I noticed yesterday on a hot restart that ACT was 95 when ambient was in the 70’s so I’m thinking it’s all the hot air in the intake track.

I found this wondering if it could help?

if the extra fuel makes it rev higher then that means its not extra fuel

sounds like you need to dial in idle air

Im using mechanical idle and pretty confident I have the throttle stop set correctly. Is that what you mean or talking about the isc multiplier for startup?

yes

Ive verified I have the throttle stop in the correct position. I set the isc multiplier back to the original a9l2 settings and am going to work on dialing in startup enrichment first and then air.

For startup enrichment what’s the best way to dial it in when she first pops off before the wideband reads cuz it’s warming up?

For isc multiplier when desmaf has a positive correction do I want to increase or decrease the values in the multiplier table?

For dialing in air I know I want to shoot to get the desmaf correction as close to zero as possible but is it a good idea to keep the correction on the positive side assuming that means its adding air? My thinking is the isc valve would do a better job adding air as opposed to removing it.

by engine response

some engines like the zetec need to be at .7 lambda or theyll misfire, big blocks with older heads are similar

moste engines want to be at .8 to .9 lambda

increase it, but first you need to set the throttle stop correctly and ithbma so you have 0 zero at fully warmed stabilized idle

iac doesnt matter if its adding or pulling ideally u want it as close to 0 u can repeatably

ithbma should be zero since I’m using mechanical idle correct?

Once it’s fully warm I get a positive correction on desmaf but that’s normal with having an electric fan right? If I open the throttle stop anymore it idles slightly above what’s commanded before the fan demands more, I have a pmw controller. The correction is right around zero right when it warms up but increases as it runs longer.