johnny_b

Car runs leans after a pull 50 percent of the time after I restart it its fine until another wot, any ideas? Have tried 4-5 different tunes was told to check plugs about 5k on them and sc pulley gap which I believe is at 0.35 ill be checking soon, other than that car pulls hard before the issue occurs, mods are weistec plugs, tcu tune, mbh header, 180 cp, 83 sc pulley, kc, 90mm tb, 550 bosch injectors, tune, any help would be appreciated

Hulk

You have the lean hiccup
It's a tune issue and is because of the bigger tb
Some ecu get that issue and some don't
Lots of threads on this already

PieRat

I had this issue without throttle body upgrade was putting up a none engine light maf code. Turns out it was a vaccum hose loose in the right hand (facing engine) surge tank. Think its related to that metal hose over the valve cover on that side.

Hulk

If it was the metal hose then a restart would not fix it. This is the infamous lean hiccup issue

PieRat

Well I had the issue in which after driving for a bit my fuel trims would go go 25% and the car would idle like a wild bull and buck under deceleration in and in all manners act like the hiccup issue as far as I coukd tell. Rebooting the car would resolve the issue for a while. I am on stock TB. I think if the computer cannot make sense of inputs it crashes. Dealer found the vaccum leak and presto no more wild, spluttering bull mode. Surely one of the 5 tunes had the TB hotfix? Your probably right but he mightve created a leak when doing all those nice mods?

johnny_b

I was hoping it was not the lean hiccup issue mine only does this after i give it wot most of the time, it does not do it randomly driving only after a pull, sometimes if i come to a full stop it goes away until i get on it again, How would this get tuned out on a dyno?

Hulk

It's the hiccup
Some experience like you
Can't be tuned on the dyno
You need full logging and takes long time and it's not easy

johnny_b

Thanks Hulk not what I wanted to hear maybe have to step down to stock or 82mm tb again I guess, I checked for vacuum leaks none found and all new gaskets and seals

Hulk

From the stories I have heard you have to goto a 80mm

johnny_b

Great lol it was fun while it lasted.

PieRat

Just curious as to your long term fuel trims? Are any of your ignition components or ignition related sensors old? I think the computers in these cars partially crash when confused. Id not go replacing anything I was just curious.

johnny_b

I replaced the spark plug wires and plugs in the last 5K miles other than that for the ignition part everything else has not been changed, i have yet to check the ltft's, What do i look for while paying attention to them?

johnny_b

I get no codes as well that i know of when it does this, at least no check engine light haven't checked on sds yet to see if i get anything there

PieRat

Get a way to monitor short term fuel trims, note any changes in behavior when cars in mucked up mode. Also check your long terms anything over 5 in either direction from 0 is suspect.

Check codes when its still running in mucked up mode. Mine didn't show after a restart or generate a engine light but was there.

PieRat

How much boost you getting? Might need to clamp it?????

Hulk

If that was the case he would be getting into limp mode
He's not having that issue