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I'm Ready To Put A Bomb Under The F@#$ing Thing!

AdamsR33

By AdamsR33,
in Engines & Forced Induction

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AdamsR33 Mentor

AdamsR33

Posted
Posted

R33 s2, basic mods, FMIC, coils, exhaust, fuel pump, PFC new spark plugs fuel filter and oil change as requested by the tuner i think thats it, anyway, got the PFC put in and tuned, made good power around 197-200rwkw, nothing extraordinary, a few days later car starts to hesitate abit and noticed a knock reading of 75 at about 160kms full throttle in 4th, backed off and rang the tuner. Very reputable tuner too. Car has duel stage boost contrller, low boost is on 8psi and high set on 12psi, knocking only happens on high boost.

Took it in, found an air leak and also found my cat contverter was only 2 1/2inch, so tuner said fix these little problems (got 3 inch hi flow cat and fitted and fixed air leak), still problem was there and getting worse, It was happening when boost was around 0-5psi really hesitated and jerking around and now knocking in 3rd once past 5000rpm. Rang tuner but tuner too busy, waiting, waiting, waiting, tuner never rings back after several messages and after a few weeks of being away for work got back and just so pissed with the problem i didn't drive the f@#$ing thing for two weeks!

Got talking with another tuner and he said bring it down and he'll look at it, he found that it was running very lean, in the 14's. So retuned it took me for a drive showed me it was all good and off i go happy as pig in shit. Next day driving to my mums and surprise surprise the thing starts hesitating again! FARRRRKKKK!!!!!!!!

Rang tuner and said bring it down and he'll see whats happening, this time i took him for a drive showed him and he found the AFM was reading i little funny, where in the map tracer it was running where it shoudn't be, he worked out that it was running 3 cells down from where it shoud of been, fixed and...

GUESS WHAT??? its starting to do it all over again!!!!!!!!!!!!!!!!!!

Its only a slight hesitation now but my guess is it's only going to get worse.

Tuner checked O2 sensor,ok. and even though AFM reading alittle off both tuners don't think this is the cause.

Had a look at both tunes once they left the tuner and both AFR's are in the 12's, thought maybe fuel pump but it is brand new with the first tune. must be something to do with the fuel side of things isn't it??

I'm at a loss now and can't afford to just start replacing bits and pieces as so far by just fitting a PFC and a tune has cost me over 1k and i still haven't fixed the problem.

Anyone know what the hell is going on?

Ohh and to top things off, the day i was taking it over to the tuner some dickhead side swiped me! i got his number though.

tacker Mentor

tacker

Posted
Posted

Mate just look at the basics fuel filter and put a fuel pressure guage on the inlet pipe and see if your fuel pressure reg is playing up should be 32 - 34 at idle and up to around 40 - 42 ish under boost.

BHDave Grand Master

BHDave

Posted
Posted (edited)

When the guys have a go at fixing it is the injector duty gradually increasing? Is the afm voltage at certain rev points in the same situation staying consistant or is it dropping over time? I think it may be a fuel issue as well, as you have said it keeps leaning out over time. Try a new fuel filter as tacker has suggested. Put a fuel pressure gauge on it and take it for a spin, see what it does. AFM is still a possibility. If it's reading low it suggests the element is dirty. Have you cleaned it? What sort of filter are you running? Has it been over oiled?

Edited by BHDave
AdamsR33 Mentor

AdamsR33

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When the guys have a go at fixing it is the injector duty gradually increasing? Is the afm voltage at certain rev points in the same situation staying consistant or is it dropping over time? I think it may be a fuel issue as well, as you have said it keeps leaning out over time. Try a new fuel filter as tacker has suggested. Put a fuel pressure gauge on it and take it for a spin, see what it does. AFM is still a possibility. If it's reading low it suggests the element is dirty. Have you cleaned it? What sort of filter are you running? Has it been over oiled?

Yes injector duty is increasing each time they play with it, so far its been as high as 96%

Afm is clean, as for voltage not too sure but the tuner check it aswell. Standard airbox with k&n filter, no oil, i did have a pod in there the first time it was tuned though. There is a new fuel filter in there aswell.

Will try a fuel pressure gauge to see what the regulater is doing as this is the only thing i can think of thats left that affects fuel.

rev210 Grand Master

rev210

Posted
Posted

How often do you change your fuel filter?

When was the last time you changed it?

If the answer to these questions is;

* I don't have a routine for fuel filter replacement

&

* I haven't

then you have perhaps one or two injectors that are partially blocked. You will need to clean them.

This is most often the case when you have what seems like an overall AFR that is good.

Alternatively ensure you don't have too much timing.

AdamsR33 Mentor

AdamsR33

Posted
  • Author
Posted
How often do you change your fuel filter?

When was the last time you changed it?

If the answer to these questions is;

* I don't have a routine for fuel filter replacement

&

* I haven't

then you have perhaps one or two injectors that are partially blocked. You will need to clean them.

This is most often the case when you have what seems like an overall AFR that is good.

Alternatively ensure you don't have too much timing.

Fuel filter was changed a few days before tune was done.

The thing with the AFR's is that when they tune it on the dyno, AFR's are about 12's, seen the graphs myself. both tuners would never let a car go with AFR's around 14's which is what was found a few eeks after the first tune.

there's nothing aggressive about the timing, and with a knock reading of 103, the amount of timing that needs to be pulled out will leave me with virtually none left.

AdamsR33 Mentor

AdamsR33

Posted
  • Author
Posted
Fuel pump, have you got your old one handy? at 200kw your old standard pump will still handle this. So re install it and check.

Fuel pump should be good as its brand new, was changed when it was first tuned. But i still have the standard so i might try it.

AdamsR33 Mentor

AdamsR33

Posted
  • Author
Posted
Weird problem, sounds like a dieing fuel pump as mentioned earlier. Nothing else can really get progressively worse like that. What brand/model is the pump?

weird,fark yeah but i think i'm going to kick myself when i find out what it is.

don't flame it but its a walbro 255l/h, i know some people have heard bad things but my tuner flow tested it before it went in and says he uses them all the time and hasn't had an issues with them, still its a possibility and am going to try the standard pump just to see if things change or not. the second tuner said maybe fuel pump too, i'm not so sure though.

Just been thinking to myself, could it be my injectors? maybe ones farked, i do run injector cleaner evey now and again and use 98ron fuel. Have tried different fuels,bp ult, vortex98, Vpower and the mobil stuff, nothing changes though. Just trying to eliminate things so from fuel tank to motor, fuel pump, fuel filter, regulator, injectors, is that it, so pump done, filter done, was told nothing really goes wrong with the standard reg so next would be injectors so they're coming out soon and getting sussed and cleaned but as i said i run cleaner through them every so often, come to think of it i ran some through it when it first started to play up. but you never know.

rev210 Grand Master

rev210

Posted
Posted
Fuel filter was changed a few days before tune was done.

The thing with the AFR's is that when they tune it on the dyno, AFR's are about 12's, seen the graphs myself. both tuners would never let a car go with AFR's around 14's which is what was found a few eeks after the first tune.

there's nothing aggressive about the timing, and with a knock reading of 103, the amount of timing that needs to be pulled out will leave me with virtually none left.

The damage/dirtyness is already done to the injectors is my guess. If you have one injector running lean you can still have nice 12 AFR's, measured out the exhaust and have the mysterious ping you are talking about.

The factory fuel pumps have a filter sock, some aftermarket ones do not. The fuel filter does alot more work when a fuel pump sock is not catching the bigger chunks that like to sit around the bottom of the fuel tank.

It sounds very similar to the symptoms I had with my old R33 and was easy to fix, with an injector service.

Pal Veteran

Pal

Posted
Posted

is the knock there continuous, or a spike. i get spikes up to 170 on my safc if i boot the car and then quickly let it off. can happen at drags as well at end of track at top speed. maybe also a bad batch of fuel. had that too, would get little spikes anywhere from 35 up to 70. wouldn't see it knock, only on peak hold.

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