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Discussion Starter · #1 · (Edited)
Hi everyone.

After change the timing belt and water pump the car is detting under boost. Not high levels 0,9 bar, even 0,7. I have check all the post about knock and follow all the possible problems. But no way to find the cause.

It’s a GTR33 with not much modificated in the mechanical part. Its 410 Hp 1.1bar (when was possible)

Stock turbos
Power Fc
HKS boost controller VI
ARC intercooler
HKS intakes
Nismo collector
Veilside exhaust
HKS oil cooler

The question is before the belt change it was ok. I have check the belt and all the marks are where should be. Also the AFR (AEM wide band) is like before, 14.5-8 idle, 13.9 to 15.4 moving in normal driving in road and 12-11.5 under boost.
I low the ignition 10 degrees in the CAS and continue the knock (also change the CAS for other).
The fuel pressure is also ok in the gauge. I have try other pressure regulator to high the pressure to see if with more fuel it’s better. Black smoke and the same knock.
In the commander when I log the knock appear a pick suddenly from 10 to 80/90, so I thing is real knock.
I have NGK Racing sparks that I change with the belt. I put again the old sparks and continue the same.
Water temp is always in 81ºC, and intake at 25ºC . I was cheking if something is making sound or touching somewer like I read in other post, but there is not anything unconect or making any sounds in the engine bay that the PFC can consider knock.

I don’t know what more I can check :(. Maybe one injector is failing? Can one bad coil produce knock?

Thank for the answers
 

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Discussion Starter · #3 ·
I have check the CAS with a timing gun and is in 19º. The CAS is in the middle. I have check the timing 100 times and the marks are ok. Even see the piston position and the damper pulley and is also ok :confused:
 

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Discussion Starter · #4 ·
This is the Ignition map. I think its a little agrasive after see the sample in datalogit and maybe is the problem...but the car was ok with it until now.

Is possible get the original maps somewhere to compare?

 

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i see you have datalogit are you a member of the forums with them if so there are the initial settings on there it kinda looks as standard but i cant remember to be honest, if not save the map to your laptop initalise the unit then check after checking load your map up
 

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Discussion Starter · #6 ·
http://www.gtr.co.uk/forum/69607-ignition-maps.html

In this post appear one exactly the same. And looks like is for 98 and 1.2bar. But before there is 3 maps for 98 1 bar, 99 and 100. Dont know the turbos, but the ignition is much down for 98.
If the last is the standart map, is ok for 98 gas?. Just to forguet about ignition in this problem, because with this map before was running without problems.

Im not member of the datalogit forum. Thanks for the advice. Just mail them to make the account.
 

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finally, someone who posts a problem but has given enough information to work with!

something went wrong on reassembly, no question about that. And a sudden knock spike up to 90, yeah, that's knocking!

CAS is the first suspect, but you've apparently ruled that out by checking with a timing gun and using a difference CAS.

You'd know if there was an ignition problem - you wouldn't be knocking, the car would suddenly sound and feel like a diesel truck!

Fueling seems fine. 12:1 is a bit lean for me, but I run a lot more boost on bigger turbos. 12:1 on stock turbos should be fine. You would directly see fuel pressure problems on your wideband - you'd be running leaner than normal.

Have you changed the gas in your car? Last week my car suddenly did the same damned thing (knock spikes) and I hadn't changed a thing! Turns out a gas station sold me 94 octane that they were pumping out of their 100 octane pump - cheating customers. Free money for most people - guys in big Mercedes filling up with premium fuel, they neither understand nor require 100 octane fuel. But high performance cars depend on the octane rating, depend on it very seriously.

In my case, emptying the fuel tank and refueling at a trusted gas station solved things, although to be safe I pulled 4 degrees of timing on my full boost parts of my map, increased fueling to 10.8:1 at boost, and lowered my boost to 1.70 bars. It's winter, so I'm off the toluene, but I think I need to go back on it.
 

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Discussion Starter · #9 ·
Thanks for the reply.

I have used different gas and tried also octane boosters. Even the Shell 100 is making knock. Very strange.

If I go with 0.7 bar, I don’t see more than 25 in the commander. Everything up this level is knocking. Looks like retard the ignition don’t make any change on the knock. If I put more gas the knock is less, but don’t disappear.

There is something made also in the time when it start to knock. The fuel pressure sensor is mounted in a metal T. Sure is not making any sound, because is in the air, but maybe is cutting the normal fuel flow.
 

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Discussion Starter · #10 ·
So continue trying to find the knock reason. Now the situation is like this. I take out the T fuel pressure sensor and no changes of course. Change the fuel pump for a Nismo 280, and rewire the cables direct from battery with a relay. Now is a little better, but same problem. I revised again the distribution and take out the EX variable pulley and install the OEM.

Now the knock continues but is under 40 if I low -2º the ignition and set mix to 1011 (1.1% I guess) in PFC.

Also there is a new symptom. I set the EVC to 0.85 bar, and if I race the car is going up to 1.02-1.05 bar!
Maybe there is an air leak, and the EVC is giving to much boost when trying to reach the 0.85???

Any ideas???

Thanks
 

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Discussion Starter · #11 · (Edited)
Hello again with my old problem. Now im in the point of put gas on the car and burn it :flame:

I have dismount the distribution and remount again. Even change the crank pulley for other one. Maybe the rubber was slide in the old one I thought. Everything looks like should be I guess.

Crank


IN


EX


CAS is in 20º with the strobe, that is the middle of the regulation like normally.

Before when I change the ignition was no big change in the knock. Not if I back 5º the knock is less. But never pass 0.85bar.

Like I wrote in other tread, the day I change the belt the PowerFc was making wear things. Working slowly and no responding in the commander. Now works normal.

So, sorry for be annoying with this question, but have the car in this situation is killing me, and provably the engine. I have waiting lemans turbos, injectors.....and can not instal anything until I fix this question.
 
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