okay... ive been searching and trying to figure out what is causing my surging idle. first of all here is my setup. I just put together my LSVtec with b16 head with BDL throttlebody and victorx intake. everything else like sensors are stock and from my old block which worked fine.

the car starts and idles fine when it is cold or hot. but Once i give it some gas the rpm would drop below 850rpm and starts to surge. like it is about to die. sometimes the surge would go away and sometimes it doesnt. This is all during idle. Everytime i give it gas the rpm would drop really low and go back up and then it will try to steady the idle. Anyone have any clues why?

Here are the things ive done so far to try to fix the problem.

1. checked vacuum leaks.. Cant seem to find them. I blocked the intake with my hands and the car dies.

2. removed iacv and cleaned it with carb cleaner and put it back. still surging but not as erratic as before.

3. drained the coolant and filled it up again. didnt fix the surging

any more suggestions? Should i drive it around to see what happen.

Thanks

 

so you give it gas sitting in netural and it starts to die?

 

when you first start up it idles okay until warmed up. when i give it some gas it will come back down pass my set point and then starts to surge like its trying to stablelize. It will keep on doing that.

Before it would idle erraticly 1000-1500 rpm. After i cleaned the IAC and flush coolant it surge 500-1200rpm after i give it some gas.

Any idea why?

 

you sure you bleed the coolant well?? no air pockets?

you say you cover the intake and the car dies?

are all non using vacum lines plugged?

no cel?

 

I drained the coolant water and filled it up again. Dont know if that did the trick for bleeding air pockets. Dont know if there is a better way.

Yes the car died when i covered the intake with my hand.

I checked all non used vacuum ports and theyre all plugged.

No check engine if i can recall but i can double check again when i get home.

Do you think i need to drive the car to get the coolant and everything working together?

Thanks for the replies

 

you should let the car get hot with the radiator cap off so all the air pockets get out