odd responce during moring starts

[XxrusianxX]

So, here is the deal... Sometimes when I start my car when it is cold and drive away before it really has a chance to warm up it acts strange. Basically as I pull out I will start accelerating and the car will barely move no matter how hard I am on the throttle. Then after about 5 seconds the car just guns it. And this happens very suddenly so I do not think it is turbo related since a turbo can not spool that quick. Perhaps the injectors???

 

[boosted954g63]

I have the same problem. I would like to know what causes this too. I Usually wait till my car is warmed up before i go though.
Thanks Nick

 

[joosdawg]

i think all the 4g63's are like that in the cold. I just figured it was because everything is still stone cold and that makes for a real dense air charge which may lead to running a little lean which basically boggs everything down for a min or two until it gets crackin. Ive noticed it to get worse and worse the bigger the injectors you have tuned up while fully warm. This also is the reason the GM MAFT has the feature of startup enrichment mode which adds fuel for the first few min its running so it cancels out this problem.

 

[project15]

i think all the 4g63's are like that in the cold.

Mine doesn't do that.

 

[guitarhero14]

Mine does, I just let her warm up and dont give much gas. No reason to floor it when its cold.

 

[neverending]

Mine does this too, seems really touchy with constant throttle especially when its really cold out. In first, I'll give it part throttle but it feels like its hesitating, then all of a sudden it will "jump". I think it has to do with the O2 sensor being cold.

A/F is lean for a while soon after starting (during hesitation) but when it suddenly finally switches over to rich, thats when the acceleration happens. Once it reaches operating temp and the lights start closed-loop "bouncing" on my A/F gauge it feels normal.

 

[joosdawg]

Mine doesn't do that.

well if all you have is a UICP and greddy bov thats ###### why. The ecu can compensate for stock like components but when you start going with bigger injectors or substantially more airflow somhow things are gonna start being funny.

 

[project15]

well if all you have is a UICP and greddy bov thats ###### why. The ecu can compensate for stock like components but when you start going with bigger injectors or substantially more airflow somhow things are gonna start being funny.

but that's all the original poster has.