Jerky throttle/irattic idle poss egr?

[guest4137]

Hi,

I have a problem that's been developing for a few weeks on my jazz, it's very jerky when I touch the throttle and also when I release it. It's more noticeable at low speed in town. It also idles badly, it hovers around 1500rpm sometimes drops to 1000. This causes the car to jerk forward when pulling up, the car sort of kicks. The engine also shakes quite strongly when turning off, you can really feel it inside the car. A work college suggested it could be misfiring so I changed the spark plugs but its not any better, the idle dropped very slightly, it still kicks in at 1500 but eventually settles to 800 if left long enough. Sorry for the ranting but I'm trying to put as much info into this as possible but I'm typing on my phone! My car is a 2002 1.4 S manual. 135,000 miles done. I've had all the other major jazz problems, wheel bearings, gearbox bearings, door locks, ignition barrel. From reading on here the egr valve could be a possible culprit but most people seem to get sn engine warning light come on which I haven't had.

If anyone could give me a bit of advice I'm be extremely grateful!

Thanks
Andrew

[tetsky]

My jazz had the same problem..egr valve was very dirty so it doesnt shut or open when needed, experienced alot of hesitation and jerking..just take it off, its only 2 12mm bolts, and good soaking of carb cleaner...
   Or you can isolate the the egr by just unhooking the socket for few minutes and try to drive it, if the car runs smoothly, then u might have a faulty egr valve..new one will cost you 270 quid:-[

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[tetsky]

Dont forget to connect the socket again once you know that your egr is faulty coz otherwise it will show a check engine light on your dash...a cheap obd scanner from ebay will be handy..less than 20quid to reset it once you've sorted out the problem:D

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[guest869]

Same issue on my 2003 Jazz.

It seems impossible to hold say 1200rpm at idle. The revs rise to 1500rpm then drop and then rise again.

Also when tying to drive at very low throttle openings in first gear it kangaroos. It is fine at tick over or above 1500rpm.

I took off the EGR and the piston seemed to move freely. I cleaned it and it did not seem to make mush difference.

I will try again.

[guest4137]

Thanks for the reply, I tried unplugging the egr valve, felt a lot smoother but it's still jerking at low speed. The idle speed did drop noticeably but again it still seemed to kick in quite high (1250) then drop to 800. Any ideas? When changing the spark plugs one of the old ones had a white residue over it, is that a sign of anything?

[guest4137]

John, that sounds exactly the same as mine. Let me know if you have any luck

[culzean]

I tried unplugging the egr valve, felt a lot smoother but it's still jerking at low speed. 

unplugging the EGR will do nothing if it is stuck part open by carbon and other stuff (which is the normal failure mode), unplugging it will not make it close but may disconnect the sensor.  Truth is if the EGR was stuck closed you would probably never know, as it should only open at high revs to cool combustion down and reduce NOx.

[guest869]

John, that sounds exactly the same as mine. Let me know if you have any luck

Try cleaning the throttle body in the vicinity of the butterfly. Changes are it will be black and could be causing the throttle to stick slip at low openings.