Jump to content
SAU Community

Recommended Posts

So in February I had my car tuned making around 280rwkw. The car drove fine maybe a little carp down low, which I thought was the vct plug needing replacing.

The car then began flashing the cel/knock light. Replaced the vct plug and took it back to get the tune looked at. I've been told the car can't handle timing above 10psi and 4 degrees of timing was taken out anywhere above 10psi.

IAT were mid to high 50. Don't know if that's an issue.

Car has

Hypergear atr43ss2

Top feed rail with 1000cc xspurt

Jjr return flow cooler

Haltec platinum pro

Any reasons why a car would be fine with the timing then after a few months hate it.

Tuner thinks the 98 down here is bad but I can't see why it would be that bad/different

Link to comment
https://www.sau.com.au/forums/topic/467658-car-wont-take-timing-with-out-knock/
Share on other sites

How big is your exhaust? Possibly collapsed CAT? Can you check pressure or temps pre and after intercooler?

Just saw you have a Venom cat so probably not that.

Same tuner as February?

Stao might be able to weigh in here, but I believe he was having issues with JJR Belmouth dump pupes at one stage. The flange doesnt quite match up to the gasket/turbo and you need to grind out the dump a bit to make it match.

I never had this issue but I believe that it was a problem

Do you know how much timing is actually in the MAP up were the problem area is?

Ok I don't think I had the issue as I would have noticed when I went to put the gasket on.
No I don't know how much timing is in there before after the change. I may have to see if I can find out tomorrow.

If everything was working fine for a while then it changed without notice then my bet is fuel starvation, time to check the filter, FPR, pump etc

Pump is my guess, its not delivering enough when you boost!

He did mention he took a bit of fuel out of the map as the afr was a touch rich. Would that rule out the fuel system? I didn't ask either but a pressure gauge in the fuel line would tell whether there was an issue in the fuel system wouldn't it?

When it changes from something that used to work, then it is not the fundamental architecture of the car.  If it NEVER took timing then we'd go looking at the return flow cooler, the exhaust, etc etc.  So we look to things that can change.  As has been mentioned already, cat is a possibility.  After that it's fuel system, as has also been said.  What may be happening is something unexpected like just one dirty/part blocked injector.  If you get one cylinder running a bit lean it will knock and the others won't, and the mixtures may not show up too badly because 5/6 of the engine is working right.  Those Bosch injectors may or may not have the little inlet filters in them.  They can catch crap and bock really quick.

  • Like 1
13 hours ago, MatthewT85 said:

Any reasons why a car would be fine with the timing then after a few months hate it.

Tuner thinks the 98 down here is bad but I can't see why it would be that bad/different

 

The fact the tune hadn't gone leaner would suggest it's less likely to be a fuel delivery issue which is one of the causes for this kind of thing which I've seen.  To cause THAT much sensitivity at that low boost and requested timing would need to be quite the fuelling issue, not something that would be too subtle to pick up even if it was only one cylinder - imho.

The other thing (and probably more common cause for this type of stuff) is triggering issues causing the effective timing to fly way off requested timing.   Either make sure the wiring to the CAS is good, or if you can find someone with the same type of CAS then maybe try swapping them over - or anything else you have the tech to do to rule that out.

Edited by Lithium
2 hours ago, Lithium said:

To cause THAT much sensitivity at that low boost and requested timing would need to be quite the fuelling issue, 

 

sorry does that mean it would be pretty obvious if there was a problem with fuel system and its most likely not the issue?

On 11/13/2016 at 0:35 AM, hypergear said:

I'm leaning towards to what the Afr gauge say as well.

do you mean if the afr was fine or rich then there isnt an issue with fuel system(injectors, FPR ect)

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...