[Jay_G]

Right

If i fully put my foot down, when the car is in between 2k and 3k revs, the car will really start violently "kangarooing (accelerating then stopping extremlly fast)". If i only use, lets say, half throttle, its fine, and if i floor it anywhere else its fine, even when it leaves the 2k-3k revs.

I drove the car quite hard to the local business park, because i wanted to see if the fan would come on (seperate story, doesn't seem to be =/), and left it idling for a good 30 minutes) gone to go home, soon as i put my foot down it did it..

Has anyone got any ideas whats causing it?

Its a mk 97 fiesta, R Reg, 1.25

Thanks

Jamie

[tommytwotanks]

it sounds like a spark problem to me, change the plugs, and see if that cures it, then the ht leads,

tommy :D

[Jay_G]

Originally Posted by tommytwotanks

it sounds like a spark problem to me, change the plugs, and see if that cures it, then the ht leads,

tommy :D

Thats what i thought, but we where both wrong

MASS AIR FLOW SENSOR, unplugged it, works a dream

Jamie

[Jay_G]

Right, turns out it cant of been that, because it came back, but with a new problem as well

When i was going down a road, came off the accelerator,and pressed the clutch, the revs wouldnt fall for a few seconds, and started to fall extremlly slowly, but when i selected the next gear, and then came off the clutch, they fell to the appropiate amount.

But, it only happens when moving, soon as i came off the accelrator the engine would keep going like i held the throttle at the same amount, making it hard to brake.

THe car is becoming problem after problem, not sure even where to look now, its just weird as it only does it when its moving.


The kangarooing problem came back with this one, so wha tnow?

[Hometune]

Try disconnecting the speed sensor.

[Jay_G]

Hey hometune
Thanks for the reply


Now i may sound silly, but where would that be?

Jamie

[Hometune]

Wire comes up from back of gearbox.

[Jay_G]

You got it, the rev problem has disappered but get this.

Drove home from mates house, engine was cold, no kangarooing so i thought hmm, how have i got this set up, jumped out of the car engine still running, and have the MAF plugged in (with it UNPLUGGED, it stopped the kangarooing), slammed the bonnet, went to pull away and ah presto theres the kangarooing..

Dont know if its heat releated, or whe i slammed the bonnet i may of moved a dodgy connection buy any ideas?

Jamie

[Jay_G]

Right, the kangarooing is definetlly heat related, car was fine, soon as it got warm/hot, it started

If its any use, the car had a rough idle,the same time the kangarooing started, the revmeter needle was jumping up and down, (didnt go over 1000 tho)

Jamie

[Hometune]

So where are we now? Is the MAF connected? If it is connected and there is poor idle the MAF may well be suspect. If the MAF is disconnected you will get poor running as the ECU does not have reference values and so the oxygen (lambda) sensor will be trying to correct the mixture incorrectly.
It may run better with the MAF disconnected but it won't run properly. Can't help with the possible poor connection afer slamming the bonnet. All you can do is check any earth points and pull and wiggle wires/connectors.

[Jay_G]

Originally Posted by Hometune

So where are we now? Is the MAF connected? If it is connected and there is poor idle the MAF may well be suspect. If the MAF is disconnected you will get poor running as the ECU does not have reference values and so the oxygen (lambda) sensor will be trying to correct the mixture incorrectly.
It may run better with the MAF disconnected but it won't run properly. Can't help with the possible poor connection afer slamming the bonnet. All you can do is check any earth points and pull and wiggle wires/connectors.

Everything is connected, bar the speed sensor (which fixed the reving problem (thanks by the way)), but now ivstill got the kangarooing problem.

I pulled up at the traffic lights and noticed the idle was a bit wobbly, then pulled away, and the kangaroo started, so that is DEFINETLLY heat releated (when engine is hot, the idle is wobbly, and it kangaroos), so its not a connection problem..

Coil Pack?

Jamie

[Hometune]

Could be. They do fail quite regularly. There is no water getting around the spark plugs, is there? Core plugs leak and windscreen washers leak on to the leads too.

[Jay_G]

Originally Posted by Hometune

Could be. They do fail quite regularly. There is no water getting around the spark plugs, is there? Core plugs leak and windscreen washers leak on to the leads too.

Hmm, im gona try borrow a mates from his 1.25 fiesta, see if that temporarily fixes the problem, that way it'l lead me in the right direction.

I couldnt see any water, i took the cam cover off and had a look at the plugs, all looked fine

Jamie

[Jay_G]

Its being suggested, that the LAMBDA sensor it as at fault, explainging the tempature situation

Could this be it?

Jamie

[MrDanno]

Originally Posted by Jay_G

Its being suggested, that the LAMBDA sensor it as at fault, explainging the tempature situation

Could this be it?

Jamie

Test it for operation. That is the only way you will know.

[Jay_G]

I dont have the equpiment to test it, so going to borrow one off a mate

Jamie

[Jay_G]

Could a bad earth of caused this?