little advice needed

If the timing is out by one tooth or so would that make the car iddle as if it had bigger cams in it?
My mates gtir had hks 264 cams and that was lumpy.

My car on iddle isnt as much like that.
But it does drop revs as if it has bigger cams installed.

What other symptoms if any would be happening if it was out by a tooth?

I was at my mates unit just sorting an exhaust leak the other week and when I had the car on iddle he asked if it was cammed up.

I rebuilt my Evo and got the timing out by one tooth and it ran lumpy as though it was crammed up, so yes I'd say

It drives okay until I come off throttle and then it jerks like a miss fire. But obviously off throttle so isnt a miss fire.
And as I say on tick over the revs drop but like a miss fire.
Its hard to explain.
Will try and get a vid up tomorrow.

Air leaks are in the fashion nowadays.... Wold make it lumpy on tick over. If you'd have timing out by tooth there is be a chance that it would lock up.

where roughly is your dizzy set mate ? I.e. How Much of the  hole  can you see either side of the bolt

Gostek wrote:Air leaks are in the fashion nowadays.... Wold make it lumpy on tick over. If you'd have timing out by tooth there is be a chance that it would lock up.

I need to do a vacuum leak test.

johnny gtir wrote:where roughly is your dizzy set mate ? I.e. How Much of the  hole  can you see either side of the bolt

On that pic I would say it's not out

johnny gtir wrote:On that pic I would say it's not out

Okay thanks.
It was just a thought that jumped into my head.
I was sure we timed it up right when we rebuilt the engine.

I just can't seam to figure out what's wrong with it.
Its not a major pain.
Just one of those niggles.

Yeah mine runs lumpy on idle didn't have a lamda fitted so fitted that still seems lumpy I do have HKS 264 cams but think it may be an air leak somewhere but haven't been able to find out were or if there is one. How would you go about running a leak test?

Sounds a bit like this so maybe this is because of my cams... sure when I got the car back after the rebuild I didn't notice it but I did have a front exit exhaust so it was bloody stupid loud anyway.

Mine doesn't sound like those. Its like it drops a rev.

doesn't sound like cam timing to me, more like a fishbite misfire .
Always good assume nothing and look at everything though so if have doubt on chain could be idea have a look at it . I tend look at anything that becomes 'doubtful' as learned the hard way from assuming was done right don't solve the problem and keeps me awake at night pondering the dilemma lol, if it don't solve the problem it solves the doubt :-)

Mr B wrote:doesn't sound like cam timing to me, more like a fishbite misfire .
Always good assume nothing and look at everything though so if have doubt on chain could be idea have a look at it . I tend look at anything that becomes 'doubtful' as learned the hard way from assuming was done right don't solve the problem and keeps me awake at night pondering the dilemma lol, if it don't solve the problem it solves the doubt :-)

Wise words B thanks mate.
I took a video but the wind is louder than my exhaust note haha
And it makes the car sound like the engine needs shimming hahaha
Stupid shite phone mic.
Will get it in my mates unit when I can and take another video.

It could be out a tooth as that will certainly make it lumpy and in general the 264 cams wont make the car idle poorly unless they are advanced to the max on intake

You can check exhaust side by ignition timing.........so if that is where the dizzy sits and shes showing 18-20 degrees on the timing gun then you know the exhaust cam is set right, BUT that does not mean the intake cam is set right so only way to check that is by pulling the rocker cover off and physically check the cam position

In general an sr20det will not have valve to piston contact unless the cam timing is out by around 5 teeth, unless the head has been skimmed by a large degree, block has been decked or the valve lift on chosen cams is excessive which isnt the case with the Hks 264s

Also check chain tensioner to make sure that its operating correctly both hydraulicly and manually as we had a car in recently where the mechanical side of tensioner had failed so on lift off the chain went loose so timing was all over the place on run down

Thanks for that Bob.
I was going to replace the timing chain tensioner anyways.
I have new gaskets for the rocker cover to do also so will double check the cam timing.
The dizzy is set to 20°

Has it been like this since it was rebuilt Stu?

gtir_woody wrote:Has it been like this since it was rebuilt Stu?

I cant remember Chris.
We rebuilt it in 2009 and then I sold the car and bought it back a few years later.
I think it might have been tho.

Oh I didn't realise it was so long ago! anything could have seen touched over that time I guess

Yeah its been a few years mate.
When I got it back some vacuum hoses were missing off the back of the plenum that I didn't see for over a year
I will get to the bottom of it one day lpl
I have a few things to check over the next couple of months tho lol

GTI-R US wrote:
In general an sr20det will not have valve to piston contact unless the cam timing is out by around 5 teeth, unless the head has been skimmed by a large degree, block has been decked or the valve lift on chosen cams is excessive which isnt the case with the Hks 264s

That's good to know