I have posted this before but still not found the problem, so any new idea will be greatly appreciated

heres the problem,

HI, I AM HAVING ALOT OF PROBLEMS WITH MY 91 POLO GT,

SOMETIMES WHEN I AM IN GEAR THE CAR JERKS ALOT AND DOES NOT ALLOW THE REVS TO GO ANY HIGHER, IN ORDER FOR ME TO STOP THIS I HAVE TO TAKE MY FOOT OF THE ACCELERATOR AND THEN PUT IT BACK ON, SOMETIMES THIS WORKS BUT SOMETIMES IT STILLS KEEP JERKING

ALSO AFTER DRIVING THE CAR FOR ABOUT 10 MINS WHEN I COME TO A STOP AND TAKE MY FOOT OFF THE ACCELERATOR WITH MY FOOT ON THE CLUTCH THE REVS JUS KEEP GOING LOWER AND LOWER AND THEN IT STALLS EVEN THOUGH MY FOOT IS FLAT ON THE CLUTCH. THIS IS HAPPING ALOT ON THE TRAFFIC LIGHTS.

MY BIGGEST PROBLEM IS THAT THE CAR DOES NOT GO OVER 3000 REVS SOMETIMES, WHEN I AM IN FIRST GEAR IT SOMETIMES HAPPENS BUT IN THIRD GEAR + IT USUALLY GOES UP TO 3000REVS AND THEN DOES NOT GO ANY MORE AND THEN SOMETIMES STARTS JURKING. THEN WHAT I HAVE TO DO IS LIFT MY FOOT OF THE ACCELERATOR AND THEN PUT IT DOWN AGAIN. THIS SOMETIMES ALOWS IT TO GO OVER 3000 REVS. IN FORTH GEAR IT IS HARDER TO GO OVER 3000 REVS AND IN 5TH GEAR I CAN NOT TAKE IT OVER 3000 REVS AT ALL.

When i rev the car when it is out of gear it is fine and does not jerk and goes over 3000 revs.

I HAVE PUT THE CAR THOUGH full service RECENTLY

DOES ANYONE HAVE ANY IDEAS?

this is the link,

http://www.clubpolo.co.uk/forum/index.php?...=71282&st=0

New things noticed,

When the car is cold it drives perfect, it does not matter what gear or however many revs, when she gets hot and at about 90 degrees she starts having problems

Also, everyone thought it would be timing , i took it down to the vw mechanic he said if the timing was out she would drive badly most of the time.

He told me to replace the fuel pump in the tank, which i did and if anything it made it worse,

now i have noticed something new sometimes a noise comes from the exhaust, almost like shes missfiring, but not as loud.

thanks

Edited 10 July, 200719 yr by ryda

its not the distributor, as I swaped another one around and it dident make any difference, sounds like some sort of fueling problem, is there only one pump, do you think it could be anything to do with the other pump if there is any other ones

I tend to say this a lot..

but given that it only happens when warm it COULD be the lambda sensor.

When the car is warm - does it smell very rich (from the exhaust) are the exhaust gasses dark? Does it drink petrol?

Are the spark plugs sooty black? If so - this sounds lambda related.

So.. you still havn't changed the fuel filter..? Do you have a haynes manual yet?!

There are two fuel pumps - the one you've changed and the in-line one under the car.

I personally don't think its that anyway.. but hey.

edit - Have you replaced the blue temperature sender? They get the blame for absolutely everything, but at only £8 or so from VW - its worth a try

Edited 10 July, 200719 yr by Mariojoshi

I tend to say this a lot..

but given that it only happens when warm it COULD be the lambda sensor.

When the car is warm - does it smell very rich (from the exhaust) are the exhaust gasses dark? Does it drink petrol?

Are the spark plugs sooty black? If so - this sounds lambda related.

So.. you still havn't changed the fuel filter..? Do you have a haynes manual yet?!

There are two fuel pumps - the one you've changed and the in-line one under the car.

I personally don't think its that anyway.. but hey.

edit - Have you replaced the blue temperature sender? They get the blame for absolutely everything, but at only £8 or so from VW - its worth a try

hi I forgot to write the extra things i have chnaged, i replaced the blue water sensor, i replaced the lamba sensor and I also managed to change the fuel filter,

the exhaust is ok, sometimes its a little rich, but generally i would say its ok

hi I forgot to write the extra things i have changed, i replaced the blue water sensor, i replaced the lamba sensor and I also managed to change the fuel filter,

the exhaust is ok, sometimes its a little rich, but generally i would say its ok

Edited 10 July, 200719 yr by ryda

Could it be a problem with your throttle body, perhaps it needs a good clean or perhaps a new TB altogether.

I'm fairly sure the MK3 came with a port to use VAG Com or VAG software with, maybe a idea to run it through that too.

My old MK2 had a severe misfire, and at one point I couldnt rev into third gear, was fun getting home that day, but problem was solved cleaning the carb, or in your case the TB.

Cheers

Dan

Air flow meter?

Yep id go with AFM.

I have had the air flow meter swaped with another gt and the problem was still there

i had a burnt exhaust Valve a while back on my 1.0 i mean this is not accurate to your problem but did cause the same idea with what i had.

just means the valve isn't seating properly and causes the car to run crap.

i tested mine by heating up the car and then revving it and then disconnecting the 1st HT lead and it revved the same you can try this with someone who knows what there doing, but this is not a tried and tested method it just proved that the engine was p!sh.

This sounds like a problem i had with a Fiat a few years back.

My problem was that there was no compression in the engine

when it got up to running temperature.Ended up having to replace

the engine.Maybe you should have a compression test done.

throttle position sensor

throttle position sensor

if it is the tps this this should not be happening?

a noise comes from the exhaust, almost like shes missfiring, but not as loud.

on my gt when I press on the acceleration and have my hand on the gear stick i feel something engageing and disengaging,

when the car starts to have problems like jerking on the gear stick i can feel enguaging and dissenguaging which it normally only does when I am at idal and then press on the acceleration,

so it feels like the i am letting the acceleration go and then reapplying it even though my foot it constant at abut half way on the acceleration.

have you tried swapping your ECU for another one?

sounds like the rev limiter kicking in

have you tried swapping your ECU for another one?

sounds like the rev limiter kicking in

I dont think it is the rev limiter, as sometimes when i accelerate it works perfect but othertimes it stops between 2000- 4000 revs.

what do you think my exhaust is doing, why does it make a poping sound like a misfire but not as loud.

Whats that due to

well....

i had this similar problem last nite when i was playing about with the car. i was revving it and when i went to move it was almost like a back-fire... but it was just knocking...

kept bluttering and jerking when i tried to move...

and the problem was

ran out of petrol..

you might just have a faulty in-line fuel pump...

OR a leak?!

try it i think this could be your solution

ok, i will try replacing the in line fuel pump, does anyone know of anybody selling any or where to get one from.

I still find it funny that all these clues point to timing. The distributor you tried, was it a known good one?

I think it was a original gt one, and it worked perfect on the other gt

Might sound a bit obvious - but have you checked the rotor arm in the dizzy? I had similar problems to this over the weekend and it turned out to be a dodgy rotor contact lifting off the plastic body of the arm and not firing a couple of cylinders.

have you tried hooking a fault code reader into it,we did this last week and it sorted all the problems in my car so it could be worth a try

throttle position sensor

I would have to agree. Its a very simple test. Just unplug the TPS and see how it drives, will take you around 2 minutes. The TPS connector is a white (IIRC) plug that goes into the side of the TB (right hand side looking at it from the front). If that doesnt cure it, I'll eat my hat.