Laggy throttle response

[turbo_negro69]

Now with more video

http://www.youtube.com/watch?v=1wlJ13I5LZg

looked fine to me
i think you're not used to owning a car with an AFM.

[skuyler]

i still think id call it an afm problem, you said you looked at it when you take it out push the flap with your hand and see if it binds or anything

dont worry about your icv your car seemed to be idling fine

I appreciate the reply, but the AFM may be in the clear. We did take it out/clean it/inspect it. When pushing it slowly by hand, it had even resistance throughout the range of motion and nothing obvious

[NC325iC]

i still think id call it an afm problem, you said you looked at it when you take it out push the flap with your hand and see if it binds or anything

dont worry about your icv your car seemed to be idling fine

[skuyler]

Now with more video

http://www.youtube.com/watch?v=1wlJ13I5LZg

[RobertK]

Regardless... a MAF will always give much better throttle response than a flap door AFM. No matter how you tune it the flap door does add to the throttle response time.

[skuyler]

this isn't neccesarily true. you can get very good throttle response from an AFM, but most E30s have various vaccum leaks and non-working sensors that cause it to be bad. there is no "half second" lag on the throttle of my car, although when I first bought it there definitely was - turned out my throttle boot had several holes and cracks in it (that also caused a funny idle).

heh, mine had that too...squeeled at high revs also

[nando]

i know youre having the same problem, i said i think you are exaggerating the severness, its an inherent problem of the flap style afm it takes say... half a second for the air to push open the flap and then the engine realizes it needs more fuel and then vroom. it can be worse if the flap is having trouble swinging, clean your afm better, dont just spray at it, maybe wd40 a little when your done cleaning it

i woulndt spray anything at the TPS as this is an electrical sensor and not really a mechanical peice

edit: and get a BENTLEY manual chilton is a POS

this isn't neccesarily true. you can get very good throttle response from an AFM, but most E30s have various vaccum leaks and non-working sensors that cause it to be bad. there is no "half second" lag on the throttle of my car, although when I first bought it there definitely was - turned out my throttle boot had several holes and cracks in it (that also caused a funny idle).

[jlevie]

While a gummed up AFM vane can be a problem, the more likely cause of hesitation would be wear in the vane position sensor.

[NC325iC]

i know youre having the same problem, i said i think you are exaggerating the severness, its an inherent problem of the flap style afm it takes say... half a second for the air to push open the flap and then the engine realizes it needs more fuel and then vroom. it can be worse if the flap is having trouble swinging, clean your afm better, dont just spray at it, maybe wd40 a little when your done cleaning it

i woulndt spray anything at the TPS as this is an electrical sensor and not really a mechanical peice

edit: and get a BENTLEY manual chilton is a POS

[More&Faster]

i think hes exaggerating and its a normal amount of hesitation,
but to help out some i would go ahead and clean the AFM

doubt it. i have the exact same problem. at idle i can stomp the pedal to the floor and it's atleast half a second before the engine does anything at all. same thing if i flip the throttle by hand. i cleaned out my AFM and that wasnt it at all as it was perfect. i'll have to try my TPS next.

[skuyler]

checked out the AFM & TPS today...My Chilton's manual wasn't very clear about continuity and such with the TPS, but after dousing each with carb cleaner, the car seems a little better, not exactly "of my dreams," but better...

thank you guys for all your help, i greatly appreciate it

[NC325iC]

i think hes exaggerating and its a normal amount of hesitation,
but to help out some i would go ahead and clean the AFM

[jlevie]

Yes. The Motronic system can only tell that it needs to inject more fuel by knowing that the throttle has been opened (TPS idle switch opens) and by the increase in air flow into the engine as measured by the AFM. So those are the logical place to start for this sort of hesitation.

[skuyler]

Just a little? It hesistates a second then blips up the normal amount, depending on pressure...The hesistation seems worse if it is "coming down" from revs and i try to get it back up. It will drop a few more until it remembers that it is time to rev...the throttle body will be open before the car "realizes" it is go time.

With that description, should I check out the TPS and AFM?

[euroshark]

TPS. If you dont have a book, get one. That shit needs to be adjusted...If you barely give it any gas, what happens?