Car Shaking at Idle

[subiv5]

My car shakes quite a bit when idling, only does it when the car is warmed up, eg after 20 mins of driving then stop at a traffic light.

No noticeable loss of power (Car made 200kws while being tuned by Garry Capper 3 Months ago)

idle is slightly high (car has microtech ecu so has always done this since it has been tuned) so I just presumed idle was set high.

Thought it may be an engine mount, but then after doing a bit of searching on here thinking It may be missing and running on 3 cylinders.

Question: Is there anything else it could be? To tell if it has dropped a cylinder do i get a compression test done?

Any help or ideas would be appreciated

[log1call]

Yeah compression test or a leakdown or vacumm test should show whether the compressions are good.

You should check all the small vacumm hoses under the bonnet for leaks or cracks, and have a look at the plugs to see if they are all burning evenly.

[Koom]

Depending on the resolution of the Microtech, it may be hard to tune a decent idle (I had to set mine above a 1500rpm min with a Possumlink otherwise it would just hunt continuously and run way too rich).

To check if its running on three, get it warm then start it up with one lead un-plugged (Don't pull them off while its running unless you want a decent electric shock). If it gets worse while each of the leads is un-plugged then its more likely the tune.

Do you know how many cells the fuelling table has got in the Microtech? Plus how big is the MAP sensor and the injectors because as you go bigger on both those, the resolution drops and idle/low load is harder to tune.

[subiv5]

Ok cool.

First step is to test to see if any of the vacuum hoses are split or leaking.

 Koom said:

Depending on the resolution of the Microtech, it may be hard to tune a decent idle (I had to set mine above a 1500rpm min with a Possumlink otherwise it would just hunt continuously and run way too rich).

Yeah not too fussed with how it idles just concerned about what the shaking may entail, Apparently the Mircotechs are pretty crude ecu's and really hard to get perfect. Garry spent 8 hours and a tank of gas trying to iron out the niggles and get it right.

 

To check if its running on three, get it warm then start it up with one lead un-plugged (Don't pull them off while its running unless you want a decent electric shock). If it gets worse while each of the leads is un-plugged then its more likely the tune.

Sorry will sound like a bit of an idiot when asking this but..... so you mean unplug lead #1. Start car up. If it runs like normal then this cylinder is the problem. If runs like shiit then plug it back in and try lead #2 so on and so forth?

 

Do you know how many cells the fuelling table has got in the Microtech? Plus how big is the MAP sensor and the injectors because as you go bigger on both those, the resolution drops and idle/low load is harder to tune.

Not sure about any of that, car has standard injectors which are running near capacity. All I know is that he said it was a real bitch to tune (not helping that the ecu is hand controller programmable only haha) and is still running quite rich.

[Koom]

 subiv5']

[quote name='Koom said:

To check if its running on three, get it warm then start it up with one lead un-plugged (Don't pull them off while its running unless you want a decent electric shock). If it gets worse while each of the leads is un-plugged then its more likely the tune./quote]

Sorry will sound like a bit of an idiot when asking this but..... so you mean unplug lead #1. Start car up. If it runs like normal then this cylinder is the problem. If runs like shiit then plug it back in and try lead #2 so on and so forth?

Yeah thats the one. I pull them off while its running with a pair of big long insulated pliers. Not the smartest idea ;D

I'd guess its just the Microtech by the sounds of it. Mine does similar things with the old Possumlink.