Jump to content
SAU Community

Recommended Posts

  • Replies 55
  • Created
  • Last Reply

Top Posters In This Topic

Checked valve timing? Cam may have slipped a tooth or two.

Best advice is to start simple... check ALL the basics, then if not resolved, start to dig deeper. If i could count the amount of times i've had cars brought in with random misfiring, which have been looked at all around town, and something as simple as spark plugs have been the issue.. i'd run out of fingers to count with.

Edited by _x_FiReStOrM_x_
Random knocks could be oil burning under load. :unsure:

Hmmm, sounds interesting. Could you elaborate a bit more? I do notice my rocker covers are very hot after driving.

Checked valve timing? Cam may have slipped a tooth or two.

Best advice is to start simple... check ALL the basics, then if not resolved, start to dig deeper. If i could count the amount of times i've had cars brought in with random misfiring, which have been looked at all around town, and something as simple as spark plugs have been the issue.. i'd run out of fingers to count with.

Timing has been checked and even been as far changing the timing belt and the tensioners as well.

Car doesn't misfire at all, it just won't take any timing :(

So, what actually causes an injectors duty cycle to increase? Is it boost, timing or just power in general? Or is it a combination of all? Reason is, I can't figure out why injectory duty is up but boost levels are the same, but with less timing and ALOT less power.

More Airflow through the AFM should inturn use more fuel and more injector duty cycle.

Can u post up a pic of the spark plugs

Yep, generally air flow meter, coolant temp sensor, and TPS are the main sensors that affect injector duty cycle.

I cant remember where I read it. It might have been in STATUS's link. It seems that if oil is getting in the cylinder it lowers the octane rating of the mix and causes knock. If its running very hot then it will knock easier. Mine has 10 to 15 knock on wot usually. After I gave it a hiding through 4 gears it went up to 35. And yeah if there is excess carbon it will glow and cause preignition.

More Airflow through the AFM should inturn use more fuel and more injector duty cycle.

Can u post up a pic of the spark plugs

Alright then, I see. No worries mate, I'll try get some either later today or tomorrow and I'll post them up :)

Yep, generally air flow meter, coolant temp sensor, and TPS are the main sensors that affect injector duty cycle.

Coolant/water temp sits between 80-degrees and 83-degrees in regular traffic but when on the freeway doing 100km/h it sits at around 86-degrees and when cruising at 110km/h, it sits at around 88-degrees.

I'll post a pic up of the engine bay soon but on the topic of TPS, I have 2 plugs off the side of the T/B (for the TPS I'd say) and when installing the T/B onto the plenum, I had to stuff around with the TPS a bit so could a bad TPS be causing the weird issues I'm having? Or is that a bit too far fetched?

Is the coolant temp at the head normal? Also, how much carbon buildup in the cylinders? You could try a cylinder drop test to possibly find a weak injector?

The timing issue was present well before I got the temps from above. The temps used to sit around 81-84 degrees constantly, regardless of speed.

As for carbon build-up, not sure as we haven't cracked it open yet. Don't really plan to for another 12 months or so either, when I scratch some funds for a Spool 2.8 stroker hehe :cheers:

I cant remember where I read it. It might have been in STATUS's link. It seems that if oil is getting in the cylinder it lowers the octane rating of the mix and causes knock. If its running very hot then it will knock easier. Mine has 10 to 15 knock on wot usually. After I gave it a hiding through 4 gears it went up to 35. And yeah if there is excess carbon it will glow and cause preignition.

I see. We had a comp test done and it was all very even across the board, with the lowest reading coming from cylinder 3, though it still wasn't too far off from the other so the mtoor is healthy. No oil/blow-by either.

It'd be interesting to know EGT/AFR variance across cylinders... probably not realistic in this diagnosis?

I've seen some pretty funky rpm signal stuff when an ignitor was playing up.

Yeah, I've toyed around with the idea of individual AFR/EGT sensors for each cylinder but lost interest as soon as I was told the massive costs involved LOL

Here are some photos of the spark plugs :)

Spark plug 1 (predominantly white):

51297708.jpg

Spark plug 2 (black but had some ash around it for some reason):

49675700.jpg

Spark plug 3 (black):

52161599.jpg

Spark plug 4 (black):

51058040.jpg

Spark plug 5 (black with minor white marks):

47011532.jpg

Spark plug 6 (light blck/dark grey):

74435511.jpg

And here's the engine bay, hoping someone can see something wrong with it that me and two mechanics/tuners can't? lol

Also, in the bottom left hand corner you can see one of the TPS plugs resting on top of the radiator hose (has a bit of foam wedged in between though). I tried to move the TPS but I ended up rounding the head for the screw cos it was that damn tight (FML) so I couldn't move it away from the hose. Any problems with it like that sitting on top of the hose?

img0454zk.jpg

this might seem obvious but have you considered that the problem is the new plenum and intercooler? car was running fine before them. you may also have an injector problem as well but generally when stuff goes wrong you need to go back to what you changed last. in this case plenum and cooler.

this might seem obvious but have you considered that the problem is the new plenum and intercooler? car was running fine before them. you may also have an injector problem as well but generally when stuff goes wrong you need to go back to what you changed last. in this case plenum and cooler

Yeah, I've considered that actually haha but my first recordings of extremley high knock levels (120+) appeared well before the plenum and cool went on. I have a strong feeling something shat itself around that point and the timing issue was only diagnosed after the plenum went on and it went in for a tune :(

Not sure if this is related, but I saw high knocks not long after I removed the charcoal cannister. I plugged up the line that goes to the throttle body (and the stock manifold at the time) so is there any way that an incorrectly removed cannister and fuel lines associated with it cause knocking?

Is it just me or do those plugs look lean as a bastard? Lean means hot and knocking. Either that or only run for a very short time. Check this link out. http://www.denso.com...Used-Spark-Plug

I thought they were lean as shit too, but the insulator is actually white from factory (NGK 7-heat range, gapped to .6mm) so if anything, they look like the second diagnosis with the link you provided (i.e carbon build-up, pointing to rich conditions). Any ideas on that?

Anyone able to help, given the new bit of information from the above few posts?

Should also add, if I give the car a quick 2nd gear pull (i.e drive normally 1st gear, fang 2nd gear and then just drive normally through the rest of the gears) and then cruise around for 5-10mins, the hot side of the intercooler end tank becomes warm and the cold side end tank is still relatviley cool. Does that mean the air is superheated and possible cause of timing issue?

Edited by turbodragon

Anyone able to help, given the new bit of information from the above few posts?

Should also add, if I give the car a quick 2nd gear pull (i.e drive normally 1st gear, fang 2nd gear and then just drive normally through the rest of the gears) and then cruise around for 5-10mins, the hot side of the intercooler end tank becomes warm and the cold side end tank is still relatviley cool. Does that mean the air is superheated and possible cause of timing issue?

My intercooler is exactly the same after a bootfull. If its coming out the other end cold then its not an issue. Maybe a pressure test either side of it is in order. Make sure its not blocked. Unlikely tho. Beer Baron is on the money. It was fine before and not now. There wouldn't be a huge change in the tune before and after so it seem like its time to rip of the new bits and thoroughly sus them out. Put the old bits back on and see if the problem is still there. I wouldn't worry about carbon build up cos that crap takes a hell of a long time to build up enough to get hard and stay there. It usually get vibrated/burnt loose and comes out the back. You can spray atomized water through the throttle body when the car is idling and it will soften it up and break it loose also.

Edited by Room42

Ahh I see. I'm going to hook up a temp gauge on either end of the 'cooler so I'll know the exact tempereture that's going in and out fo the core :)

Nah, I don't think it's any carbon build-up as it's far too sudden to cause an issue like this.

One thing that has been mentioned to me by Plazmaman though is to check the TPS. If the TPS is responsible for the issues, I wouldn't be surprised as I did attempt to mess around with it when fitting the throttle body onto the plenum.

dscf0952z.jpg

Basically the bottom plug (grey) was getting pushed and resting on top of the radiator hose so I tried to move it by undoing the 2 screws holding the TPS in place. I did not succeed in this as I rounded one of the screw heads.

How can I check that the TPS is in working order? I checked it with the hand controller of the PFC but I'm not sure I believe it as another time I unplugged the VCT plug but the hand controller was telling me it was still working lol

Also, I heard that manual S2 R33s only use one plug for the TPS, with the grey one as a spare and not having any wires from it. My grey one has wires connected to it though. Anyone shed some light on this?

Edited by turbodragon
Automatic trans use the second plug

Maybe your car was auto that was converted to manual

I'm pretty sure my car has been a manual all along though. Dash cluster is a manual one, the stock ECU that came out was a manual one and there was only one other owner of the car before me. Weird.

I know that when I unplug the brown plug, the idle changes. But is there any way of checking the TPS?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Seat of the pants assessment of the new intake: The car is way less "doughy" when hitting the loud pedal, especially off idle when stopped or in traffic, I did use a cheapo lazer thermal thingo to measure the temp around where the pod filter got its air, it was between 55 - 60°C, in saying this the car was shut off and not moving, so the OEM intake pipe was not supplying any fresh air to where the pod was when the car was at least moving A weird bonus was induction noise on the throttle in the cabin increased a bit,  I was worried that I was actually going to lose some of that induction noise I love so much, outside though, when I got the daughter to do a WOT drive by pass for me, the induction noise has increased alot when on the throttle, not quite ITB doort, but well up there I'm extremely happy with the results and have been exploring the country roads in the region  As for house mods: 1.New front fence is up and is awesome, it really upgraded how the joint looks from the street, and the added security is nice 2. Electricians have replace some interior lights, and with more lighting in the garage, a few new motion detecting lights out the front above the garage, front room, and at the front door, which I have already found heaps helpful coming and going, also now has fancy pants CCTV all round the house The only hold point for power though is the solar and batteries due to supply issues, although this will happen over the next few weeks 3. I have done a heap of landscaping out the front and I'm almost ready to do a new small retaining wall with some nice blocks to replace the brick and cemented in rocks around the raised garden beds cemented in river stone "was the fashion at the time" the house was built. I currently have a pallet of retaining wall blocks and 2 bulka bags of 20mm blue metal to replace the wood chip that is in the raised garden beds around the house 4. I now have 3 big raised garden beds for out the back to grow some vegetables, about 70cm high, 200cm long and 100cm wide 5. My 2 compost bins are already pretty full with brown, green and kitchen waste from the landscaping I'vedone so far, but they will probably take a few months to break down, so anything else that gets chopped, trimmed, and kitchen waste will just start filling the base of the raised garden beds to about 30cm before I start throwing 40cm of good compost, and stuff, for the vegetables to grow in, I'll need a few ton of compost and soil, but the local supplier can sent me bulka bags of the stuff Basically the logs, wood chips and a few strategically placed rocks for drainage, will give the beds some good organic materials down low to break down over time, and they will hold moisture during the warmer months to save the water in my big arse water tank if we don't get alot of rain So, all in all, the car and house mods are going well, and I'm really enjoying being retired, I sleep in too 0700 and slowly plod around inside until I feel like actually doing anything, and only work in the yard for as long as want, which has actually been alot over the last few weeks,  although when you look at it, it seems that not a huge amount of work has been done,  until I look at the before I started the work pics Happy days and good times indeed 
    • hahaha yeah. Plan is to get side skirts and probably just rear pods. But going to do them one-by-one. I've got a set that I really like from RHDJapen, but that one isn't shipped to AU. So need to find someone who can get it for me
    • Here's an idea, answer the questions I asked you as they are trying to work out WHY the LSD will be binding up in a straight line.
    • You haven't driven many modern cars then have you? Most of them have sfa steering feel with their stupid electric bullshit steering systems.
×
×
  • Create New...