Club G40 Forum

Technical => Engine and Transmission => Topic started by: dub-disaster on August 25, 2011, 06:15:27 pm

Title: Strong virbations at idle
Post by: dub-disaster on August 25, 2011, 06:15:27 pm
set my ignition timing today but had a couple of problems. One of which was when i unplugged the blue temp sender the idle dropped i thought it was ment to increase ? was this because my engine wasnt hot enough ?? i warmed my engine up untill for about 10 mins water temp showed just over 70 degrees and the oil pressure had dropped back to about 60 psi from about 85. I then set the idle with the idle screw and put the blue temp sender back in and the revs raised again.

Now when i let the engine idle it sounds like a tractor and vibrates like hell  makes the whole car shake, is this because of the ignition timing or is it cam timing or maybe even worse just an unbalanced rotatoing assembly (i did get the entire assebely balanced including clutch cover flywheel and cranks)

Any ideas ?
Title: Re: Strong virbations at idle
Post by: cheys03 on August 25, 2011, 06:25:22 pm
Do you have a wideband lambda gauge?
Title: Re: Strong virbations at idle
Post by: dub-disaster on August 25, 2011, 06:26:09 pm
yup bang on 14.7 when idling and when revving
Title: Re: Strong virbations at idle
Post by: Andy on August 25, 2011, 06:50:11 pm
Have you set the ignition timing yet?
Title: Re: Strong virbations at idle
Post by: Jezza-7 on August 25, 2011, 07:08:51 pm
If your free tomorrow i can pop over mate?
Title: Re: Strong virbations at idle
Post by: dub-disaster on August 25, 2011, 08:29:46 pm
i set the ignition timing but i only set it up using a timing light without advance so im relying on the non g40 pulley and the non g40 cam belt cover marks.

When i did swing the dizzy anti clockwise the idle speed slowed down i continued to swing it in that direction untill the engine stalled. i then reset the dizzy to original position plugged blue sensor back in, re started the engine and then unplugged the blue sensor again this time swung the dizzy clock wise and the idle speed sped up but at no point did it smooth out was stull pretty lump sounds like a tracotr and is vibrating like hell! Wouls have thought if it was just a case of the iginiton timing then swinging the dizzy about it should have smoothed out the idle at some point ?

jezza mite be about 2mro afternoon finish work at 12 but not sure what im doing yet ill give you a text tommorow when i know what im doing.
Title: Re: Strong virbations at idle
Post by: hayesey on August 26, 2011, 09:22:30 am
is it misfiring at idle?  Remove plug leads one by one and see if it stays the same or gets worse. They should make it worse, if you remove one and it stays the same then it's not firing on that cylinder at idle.
Title: Re: Strong virbations at idle
Post by: scotsjohn on August 26, 2011, 05:04:36 pm
Check the vacuum pipe to the ECU hasn't come loose; that gives same symptoms.
Title: Re: Strong virbations at idle
Post by: dub-disaster on August 30, 2011, 04:52:36 pm
I today attempted to drive the car for mot, got as far as the petrol station and found the car was running extreemly lean ( 16 on wide band but 16 is as far as it goes!) on part throttle and on light load doesn't pull at all feels very weak I'm assuming this is due to lack of fuel.
   It's not misfiring died a Cople of times at idle from cold.
Have now had enough and shipped the car of to a garage (Tsr) to fix an oil leak from the endplate at the cambelt end of the block as it's leaking from where the oil gallery in the end plate meets the block I think it's the rubber tube between the two. I asked them to check mechanical timing and cam timing while there at it.
    My main problem now is this running very lean as it's dangerous. Especially as the engines just been rebuilt. I injectors where cleaned and tested, fuel pumps new no leaks, fuel filters new. Chip is ment for my spec. Maybe pressure regulator any one had any problems with theirs. Could it be 51mm throttle body letting in to much air at part and full throttle? Felt very slow when give full throttle hardly moved at all!
Title: Re: Strong virbations at idle
Post by: hayesey on August 30, 2011, 05:05:50 pm
what chip is it?
Title: Re: Strong virbations at idle
Post by: cheys03 on August 30, 2011, 05:56:22 pm
You can richen it up with the CO pot.
Did the engine get warm? If it's still quite cold it won't go to lambda adjustment and will rely on the absolute values in the map...which can be richened by turning the CO pot in (reducing it's resistance across pins 1&3).
Title: Re: Strong virbations at idle
Post by: dub-disaster on August 30, 2011, 06:32:43 pm
It's a g40008 chip from Andy, and I'll give the co pot a tweak when I get it back although I didn't think the co pot tweaking could make such a large difference to the mixture. Thanks the tip though.
Title: Re: Strong virbations at idle
Post by: cheys03 on August 30, 2011, 08:22:08 pm
Did it get warm on your run to the petrol station? Also, I take it you've kept your standard lambda sensor, it's not running as an output from your wideband is it?
Title: Re: Strong virbations at idle
Post by: dub-disaster on August 30, 2011, 09:23:46 pm
Yea kept standard lamda aswell as wide and and didn't get a chance to get fully warmed through I wouldn't of imagined. I assume this points to co pot as you mentioned before the ecu won't be making adjusments in the warm up period, just out of intrest is it just water temperature sensor (blue) that tells the ecu when the engines warm ??