hey folks, got this intermittent problem driving me nuts !
when you accelerate using about half throttle, the acceleration is a little uneven.
Like it'l push then ease up then push and ease up again like it dosn't know weather to go or not. Its like there's a blockage or partial blockage in the fuel delivery.
So you give it some more throttle (gradualy ) and all of a sudden it drops down a cog and goes burko 'cause you've got so much throttle on.
There are some other variations on this too, but its a long story.
The next day it could be the same or it could be perfect, or it could start misbehaving after a short stop, its really hard to get any kind of pattern out of it.
Obviously it needs to be playing up when I take it in somewhere to get looked at.
Anyone got any ideas ?...

b well,D.

My AE82 corolla does this when its cold, accelerates, then lifts itself off like it wants to drop back to idle then kicks back in pretty hard.....we're thinking its something to do with the fuel pump on the rolla, might be worth getting that checked out, not like the fuel pump isn't a standard part on cars.

throttle body problem or afm area

maybe the tps is on the way out??

this sounds like the dramas that my car has been having for the last year or so.
it could be anything like fuel sytem or electrical system or mechanical.
however last time i was in perth i finally got round to getting briefly looked at by my sisters b/f (mechanic) and he reckons that the timing belt has slipped a notch. the fact that it is due for replacement (free labour - yay) sort of backs that up.

so yeah , check ur timing belt.

*edit* my car has also been backfiring alot lately , so if yours does too - now or eventually - then our symptoms match perfectly. keep us updated. no doubt you will get yours looked at before me :-)

thanks for your replies folks,
yeah I was thinkin' it had to be fuel related, not sure if the fpr replaced the fuel pump or not.
hadn't thought of the throttle body and I guess afm is air fuel meter? or mas/maf.
don't know what tps is but sounds familiar.
maybe the timing belt got messed with during engine exchange.
yeah that gives me some ideas to get looked at anyway, thanks very much folks.
anyone else had similar experience or ideas ?

b well, D.

it could be that you aren't loading the motor up quite enough to get into open loop, so it is working of the o2 sensor still, this will give you a hard/light acceleration feeling as it is going lean/rich. you could try uplugging the o2 sensor to keep it in open loop all the time and see what it does.

Could easily be the fuel pressure reg. I've got a similar issue with my TP atm which feels like it "steps" up the torque in noticeable steps every 500 RPM... it's really annoying when accelerating coz after a while it tries to drop down a gear to accelerate and revs like crazy!

If you are having troubles starting the car or it's taking more fuel than usual too, fuel pressure reg is something I'd definitely be looking at.

Yes ! thats exactly what its doing, increasing the tourque in steps, thanks for that.
Other times it seems like its not tuned at all and just wants to fart and carry on.
Other times you just wanna close the gap in front, so you increase throttle gradualy
but nothing happens for like 3 or 4 seconds and 30 or 40 mm of pedal movement and
then its like it goes, "oh you wanna go faster?, ok here you go" BANG! drops down a
gear or two and gives you everything 'cause of the eventual throttle position.
Most infuriating ! yeah I'll definatly point them in that direction, fpr and air sensor.
funny thing is fuel economy is mint ! I can normaly keep it around 11L/100K even with
regular lead footing, but this tank's been around 9.5 after richening the mix a little !:nuts:
No trouble starting thankfully.

b well, D.

it could also be your tps playing up.

it could also be your tps playing up.

haha too slow i got in at 3rd post

oh well, you get that.

I have a similar problem with my car.

How would i go about checking it out? Is it all in the fuel injection?
If anyone here thinks its not to hard to set please give us a yell on how you guys did it or if theres just a simple way, otherwise i might get that checked when i go for a service.

what is tps ?:confused:

b well, D.

what is tps ?:confused:

b well, D.
Throttle position sensor.

Throttle position sensor.
oh ok, thanks for that.

b well, D.