Thread: car bucks when cold?? Any ideas?

When i first get in the car in the morning and it's cold it bucks pretty violently around 3k. Once it warms up it's fine. Any idea what the problem could be?
Here is a short vid, The problem was very mild for the vid, figures right, you can hear what it's doing, but usually the rpm needle is jumping around and it's really bucking.

damn your car is slow as hell. lol. just kidding, im not sure why it would do that. Have you double checked everything to make sure everything is plugged in?

My car did the exact same thing after I went through a puddle and got my filter and maf all wet. I just reset my ECU and it went away.

Try swapping in a known good maf and see if you still have the problem. Also at around 3k may have something to do with EGR. But I'm assuming you aren't running one.

yeah, no egr. i'll have to see if i can track down a z32 maf

my car does the same thing but not violantly like that. it just kind of feels like its missing in the low rpms but after it warms up its gone.. my egr is gone to...

Chad, i have a spare Z32 maf too.

did you get the intake manifold installed yet?? if so, post some pics!!

Doubt this is it either because this was on a stock 240 but very similar.

I had a 98 240sx se. It would missfire and or buck when cold. Turned out it was an intake manifold gasket leak.

ok, i know this video quality is terrible, it's from my phone, but you can see in this one the boost gauge and how it drops down and then goes back up.





I haven't gotten it installed yet, i'm waiting till winter, i don't want anymore downtime this year. I'll let you know if i need a new maf, i'm gonna try to try someone's out locally first.



I'll find out this winter, I'll be replacing all the gaskets when i put the above mentioned intake on.