Knock

gtirx2

Member
Right i am quickly getting peed of with my R in a big way:evil: I have just put the engine back in and gone for a blast up the road and all felt fine bar a boost leek at first so i sorted that and went for another blast and to my horrer when i got back i had a peek knock reading on the afc-2 of 192:shock: :shock: before you say you have killed you R i am pretty sure it is ok as it was only a short blast and only realy 2nd gear bursts and not for long.
So i am just wondering what may have caused this as before i took the engine out it only ever realy peaked at about 20- 30 every now and again also before i took the engine out the highest ever knock i ever saw was 102 and that was trying to max out the standed turbo at 1.4bar+ and when that happened there was a very notisable jerk :oops: :doh:
Also i have notised that at idle my boost gauge is reading 0.5 bar vacum and i was pretty sure before that it only read 0.4 before so i thought i had a vacum leek so i presserised the system and the only leek i found was one where the vacum pipe joins on the dump valve,it is a very small leek where the metal pipe comes out the dump valve so that another thing i will have to look at:evil: so i took the pipe off the d/v and blocked it up and still i am getting 0.5 vacum at idle and i can not find any more leeks and thats with 2 bar air pressure in the system:?
So what i am asking is what is the vacum ment to be at idle?and would this cause it to have knocked like that if it had a vacum leek?
This was also my first time i had realy had a good chance to test my msd set up and i am also wondering if this could have make it knock like that?
The car is only running a bar atm so it is no different than the last time when it was on the road.
I have also changed the exhaust cam for another standed one but i realy don't think it could be that?and i have also changed the turbo for another standed one and i am 99.9% sure its not that also.
Sorry for the rant but for it to have knocked at peck of 192 has realy got me worried and pissed off as i have realy not changed that much and have never seen that much knock before on the afc-2 before plus the car felt fine pulled well and with no doggy noises or jerks:? :sad:
So basicly what i am asking is what should the vacum be at idle?and do you think my msd set up could have caused it to knock like that?
Thanks and sorry for the spelling mistakes rich.
 

gtirx2

Member
Just to add the knock at idle is the same as it was before if not a little better a i have reshimed all the valve clearences again and they are all bang on 0.15.
 
P

pulsarboby

Guest
glad the turbo's ok:-D .
vacuum at idle should be around zero
i would double check the gauge as that could be faulty!
cant understand why it would show boost at idle:? gotta be a faulty gauge unit
do you mean -0.5? or +o.5
 
Last edited by a moderator:

Fast Guy

Moderators
Staff member
My vacuum at idle used to be -0.55 on the gauge, after a lightweight flywheel went on it dropped to -0.35.
 

Fusion Ed

Active Member
Basically the lower the idle vacuum the better, to an extent. Most pulsars will not idle right at -0.35 but are fine from -0.45 to -0.55

gtirx2, check the timing etc. If you want a second opinion I'm not far from kent.
 

gtirx2

Member
Thanks for the replys guys;-) ,yep the turbo seems all good thanks bob pulls well:-D .
So maybe i don't have a vacum leak after all as mine is at -0.50 to about -0.52 at idle so i think that may not be the problem.I will try checking the timing again tonight to see if that helps as i set it in a bit of a hurry and i have to slip my clutch to get the idle down and thats ackward with a paddle.
I also am going to fill the tank with frech v-power and see if that helps as the fuel thats in it could of gone off?
It just makes me wonder if its the msd setup i have on the car that could have caused it but i am not sure if it could as all it does is make a bigger spark and that should not make it knock like that?
Anyhow i will have a play and see what happens but it may have to wait till sunday as thats when my insurance starts again plus i need to get it taxed again and i don't like the idea of getting pulled by the plod.
Thanks guys:-D .
 

Fusion Ed

Active Member
MSD will make no difference, and i really dont trust the way to hold down the RPM with a clutch.. It might work but with -.55 bar it should idle fine.

Ed
 

gtirx2

Member
Oh ok so the msd should not be the problem,i have always had idle problems with both my R's over the years the only time i have had a good idle is when i first brought my R and then that only lasted a week and i still can't remember great how well it idled back then lol and i have tryed every thing to solve it but no joy.Even if i try and turn the fuel down on the afc so that it idles right it sounds rough at them sort of revs.
And when i try and set the timing and unplug the tps the rev rise even more and the only way to get my revs down enough is to slip the clutch.
 

stumo

Active Member
If you set the timing with the throttle pos sensor connected you'll not set it correctly and the revs will be higher than they should be.
 

gtirx2

Member
Yep idle screw all the way in,the dam thing is still doing my head i took it for a few more slow runs up the road and it seem to knock a little bit coming on boost in second 40-80 and just about when you are about to make full boost it knocks up 190 odd and when full boost is made i think it stops knocking like that it seems to knock is at its worst when coming on boost and mainly in second:? .
Tbh i have not had a good chance at testing it much in the higher gears as i am still uninsured and do not want to go an the a roads just yet, but coming on boost in 3rd under heavyer load it don't seem to knock like it does when coming on boost in 2nd?i was wondering if the turbo was spooling quicker than my old ones and that could be causeing it, but is still only making 1-1.1 bar boost when it fully spooled up like my old turbos that were on it, and this is on a forge actulator pressure only.
I also tryed retarding the timing a bit and that still did not help and still would knock the same coming on boost in 2nd,i tryed changing back to the standed coil with out all the msd stuff conected up and like you said that made no difference either.
One thing that i still will look at is when i put the cam chain back on i counted 11 links from dot to dot on the inside links on the timing chain when i think i should of been counting the outside links from dot to dot on the cam spockets if you know what i meen either way i don't think that makes any difference to the cam timing anyhow, but i will change it to the out side links just to be sure.
Would it make it knock if i had made the valve clearences to tight?
I am pretty sure i had them all spot on when i shimmed it with them all bang on 0.15 cold but i will still also check them hot when i change the chain position over to the outside links.
And to top my evening off when i was reversing out my drive i caught my wheel on a concrete slab and knocked my tracking out somehow,and i only just caught it, hardly enough to mark the tyre:cry: :evil: , and god knows what it has moved as it all looks normal maybe it jumped the thread on the track road end?
Anyhow if i can not sort it out i may have to bring it to you to have a look at it when i get tax and that,are you able to lision for knock and can you map the apexi afc-2's,also what do you charge an hour?
I may be able to sort it yet you never know but if i can't i may have to let you have a look at it;-)
 

gtirx2

Member
stumo said:
If you set the timing with the throttle pos sensor connected you'll not set it correctly and the revs will be higher than they should be.
No i set it with the tps disconected but it still idles to high and reads something like 40+ when idling that high,the only way i can get the right reading is to slip the clutch so it idles at around 900-1000rpm.
 

gtirx2

Member
Well i think i may have sorted it out know:p i still have not double checked the timing yet but in the end i retarded the timing back to max retarded and it stopped the knocking coming on boost and after a dam good beating i got a max knock of 8.
The thing is i have not double checked so i am not sure where the timing is now but if its stopped knocking it must be somewhere near right but the the distributer is at max retard:shock: and before it used to live in the middle somewhere in the adjustment :? .
Do you think this could be because i changed the exhaust cam and the slot in the end of the exhaust cam where it drives the distributer maybe at a sight different angle than the old one:? ?
Where do your lots distributers sit when at 18-20 degrees advance?
Or my other option is that the reason why the timing seems right at max retard postion is because when i put the timing chain on i counted the inside links on the chain from dot to dot on the pulleys other than the outside links like you are ment too,but to be honest i can't see why this should make a difference to the timing as all the links on the chain are the same size be it an inside link or an out ?
So i will see what the timing is tommorow and if it is close i will try and change the cam chain postion over and see if that makes a difference,but i am a bit concerned as to why i have to run it at max retard on the distributer to get the timing right:mmph: .
So i have learned that when you time it up don't rush and take it for granted that the timing was about right as the distrbuter was in about the same place as last time,oh and to also get some glasses:oops: :oops: :oops: :doh: .
 

gtirx2

Member
Right i have changed the timing chain back over to the outside links like it should be and all is fine again distributer is back in the right postion running well:-D :-D .
Tbh i did not think that putting the chain on the wrong links would make all that difference as you would think that be it an inside link or an outside link on the chain, as long as there is 11 links from dot to dot on the cam pulleys with cams in correct postion and on tdc it would have behine the same,but when you set the exhaust cam woodruff key at the top when you set the cam timing if you are on the outside links it sits very slightly to the left of upright where as if you set it on the inside links it sits ever so slightly to the right of upright which was making my R run so much advance.
Lesson learned:oops: :doh:
 

gtirx2

Member
It was lol, i am glad i noticed it on the afc before i gave it a good beating,i hardly run it like that for long and only saw the 190's a couple of times for a split second so i think its still fine,compression check is pefect and it is running very well now.
How long does it take for det to kill an engine as i am hoping that my two little 2nd gear bursts that it still should be fine?
I am still surprised that the dam links on the chain made all that difference:doh: .
 

gtirx2

Member
Oh just to add when you try and set the timing with the msd kit conected you get 4 timing dots flashing on the crank pulley instead of just the one as the msd kit has mulitiple sparking up to 3000rpm!
 

dave

New Member
so if i have connected the MSD kit (MSD 6A and MSD Coil Blaster SS) does it affect? if i tried to set the timing with it connected?
 

gtirx2

Member
dave said:
so if i have connected the MSD kit (MSD 6A and MSD Coil Blaster SS) does it affect? if i tried to set the timing with it connected?
If you try and set the timing with the msd kit connected you will see 3 or 4 timing dots flashing on the crank pulley as the msd has mutiple sparking below 3000rpm.You can proberbly get it right if you can work out which dot you want but it is far easyer to swich back to the normal coil just to set the timing.
 

dave

New Member
another question, when i am setting up the timing i have to put it at 20 degress (the last dot to the front of the car at crank pulley) am i right? and that is set at idle speed right?
 
Top