Petrol In The Catch Can?

[race_snooze]

17 psi is 1.1 bar

[r33_racer]

you can go upto 300rwkws so long as tuning is spot on....no problems.

[GunMetalR33]

update:

Just sneaked out of the office, and went for a qiuck run. Guess WHAT? She went Ka Boom.

Na, just joking. I wound the boost down to 1.26 bar (17.5 psi give or take) and the power delivery is much smoother but not quiet as vicious. I think it was surging a tiny bit before now that I think of it.

So on the weekend I will re-gap the plugs to .75, set the boost at 1.25 bar and change the oil AGAIN and empty the catch can. Will keep you guys posted.

At this point I think the fuel in the can is a result of blow by mixed with some hardcore flat spotting. The fuel will endup in the can before any oil as it will turn to a thin vapour quicker than the oil will...

Hopfulling I wont be see anymore fuel in the can once I have taken the above measures.

[Beer Baron]

when you change the oil, put some of it straight into a glass container and send it away for analysis. all will be revealed. if fuel is contaminating your oil i would be more worried about bearing wear, as they wont last long with a nice fuelly oil mix lubricating them, then it's spun bearing - seazed bearing - hole in block.

[GunMetalR33]

OK, I have just drained the oil and was wondering if there is some way to flush out all the left over oil in the engine before I put the new stuff in...

Any ideas, products etc???

[Beer Baron]

nulon make an oil flush, but you need to add it before you drop the oil. basically it thins out the oil so more of it runs out. not a good idea to run the eninge too much with that stuff in it, and i dont use it at all.

just get the oil nice and hot (like 90-100 degrees) then drop it out.

[GunMetalR33]

nulon make an oil flush, but you need to add it before you drop the oil. basically it thins out the oil so more of it runs out. not a good idea to run the eninge too much with that stuff in it, and i dont use it at all.

just get the oil nice and hot (like 90-100 degrees) then drop it out.

Done and done mate.

I appreciate all the comments that all you have made. So this is where we stand at the moment:

I changed the oil and it probably still had a little bit of fuel in it. There is new motul oil in there now and the boost is down to 17.4 psi. Knock is low as always and my irraway 7's have been gapped back up to .75. The car pulls fine but not as hard as before. However it is alot smoother as I think it was surging a little before.

Tomorrow I will gap the plugs out to .8 and see how she goes. I hope this is the end of this thread, but I have the feeling that I will be changing the name of it to gunMetal rebuild soon enough...

Would $3500 be enough I cant afford to smash into my home load deposit fund to much more.

[Sydneykid]

My guess would be a leaking injector (or two). What injectors are you using? Have you had them cleaned and flow checked recently? Mainly to make sure that they close off completely. They can leak (a tiny bit) over night, or anytime that the engine isn’t running. The fuel sneaks down past the rings, if you are lucky. If you are unlucky (or the leak is big enough) you can get hydraulic lock when you try and start the engine in the morning.

This would also explain the fluffy running when first started and the need for hotter plugs. Fuel evaporates at a much lower temperature than oil so that why it “boils” off into the catch can once the engine is warmed up.

So, my recommendation would be to get those injectors checked, sooner rather than later.

cheers

[Adriano]

Or the fuel pressur regulator, I once built a SR20 datto 1600 show car for a customer, with a tough motor, he took it away, and got the fuel rail and regulator chromed after it left the shop, put it back together and the diaphram in the reg had torn, filling the engine with fuel through the vacuum line, bending two conrods.

[GunMetalR33]

My guess would be a leaking injector (or two). What injectors are you using? Have you had them cleaned and flow checked recently? Mainly to make sure that they close off completely. They can leak (a tiny bit) over night, or anytime that the engine isn’t running. The fuel sneaks down past the rings, if you are lucky. If you are unlucky (or the leak is big enough) you can get hydraulic lock when you try and start the engine in the morning.

This would also explain the fluffy running when first started and the need for hotter plugs. Fuel evaporates at a much lower temperature than oil so that why it “boils” off into the catch can once the engine is warmed up.

So, my recommendation would be to get those injectors checked, sooner rather than later.

cheers

I put nismo 555cc injectors in myself. BUT i did not change the O-rings when I did it. Since then, some times it can be a little hard to start but not often. You just have to turn it over a bit more and she starts with a puff of black smoke which I guess is unburnt fuel.

The injectors are only 3-6 moonths old though...

Edited September 8, 2006 by GunMetalR33

[GunMetalR33]

Could worn O-rings be causing the injector to leak, remembering that they are side feed injectors?

[GunMetalR33]

anyone?

[Sydneykid]

Could worn O-rings be causing the injector to leak, remembering that they are side feed injectors?

Leak to the ouside world = yes

Leak into the engine = unlikely

Fuel in the catch can = running rich = too much fuel. If it isn't injectors leaking (into the engine) then it is something else causing the rich running. Dirty AFM's, poor tune, excessive fuel pressure etc all stuff that should show up on the dyno.

cheers

[GunMetalR33]

thanks for the reply SK.

The fuel mix was something like 12:1 and was a straight line on the dyno graph when it was last tuned.

Previously mentioned:

"I put nismo 555cc injectors in myself. BUT i did not change the O-rings when I did it. Since then, some times it can be a little hard to start but not often. You just have to turn it over a bit more and she starts with a puff of black smoke which I guess is unburnt fuel."

Should I take the injectors back out considdering they are only about 1 year old? Or just put it on the dyno again?

[Sydneykid]

thanks for the reply SK.

1. The fuel mix was something like 12:1 and was a straight line on the dyno graph when it was last tuned.

Previously mentioned:

2. "I put nismo 555cc injectors in myself. BUT i did not change the O-rings when I did it. Since then, some times it can be a little hard to start but not often. You just have to turn it over a bit more and she starts with a puff of black smoke which I guess is unburnt fuel."

3 and 4. Should I take the injectors back out considdering they are only about 1 year old? Or just put it on the dyno again?

1. That’s a full power, WOT test. So it is 99% irrelevant, how much of the time do you drive around at WOT? . More importantly, what are the A/F ratios as partial throttle openings? At idle? What are the acceleration enrichment settings? Cold and hot start settings?

2. Together with the fuel in the catch can, it is the black smoke on start up that has me concerned. Give it a run on the dyno, but make sure you test idle, cruise, acceleration enrichment, partial throttle openings etc.

3. I would also have a good look at the fuel pressures, just to be sure that increasing fuel pressure is not the problem.

4. If that doesn’t show up anything then I would have the injectors flow tested. If one is rich for some reason, then the other 5 might be lean, giving 12 to 1 on average.

cheers

Edited September 11, 2006 by Sydneykid

[GunMetalR33]

1. That’s a full power, WOT test. So it is 99% irrelevant, how much of the time do you drive around at WOT? . More importantly, what are the A/F ratios as partial throttle openings? At idle? What are the acceleration enrichment settings? Cold and hot start settings?

2. Together with the fuel in the catch can, it is the black smoke on start up that has me concerned. Give it a run on the dyno, but make sure you test idle, cruise, acceleration enrichment, partial throttle openings etc.

cheers

1. Partial throttle, idle were done when tuned, but acceleration enrichment settings and Cold and hot start settings I am not sure about. Where in the PFC HC is this info? and how can I make sure its correct?

2. The black smoke only happens when its hard to start which is about 1-3 times every six months or so. Basically I turn the engine over as usual BUT it needs to be turned over several times before starting. Then when it finally starts it blows 1 puff of black smoke. But like I said it does not happen much??? Its this that makes me think that its a leaky injector...

I am going to start by getting a new set of plugs. The irraway 7's that I have in there are almost 2 years old and they flat spot a bit. I have since change the their gap from .6 to .75 aswell. Flat spotting would be the same running rich in this context right? So the flat spotting could also be causing the fuel in the catch can???

Edited September 11, 2006 by GunMetalR33

[nfi]

When you saw flat spot you mean the spark is breaking down? Hence gapping the plugs right down? Do you have stock coil packs?

My guess is that your coil packs are either screwed or not strong enough for the power you are making. Hence the requirement to gap the plugs down so much. As a result you are not burning the fuel properly and its just bleeding down past the rings and there you have it, its in your oil.

My 2c.

EDIT: Just read the second page after posting- SK's theory on the injectors sound much more likely than my wooly theory. Even brand new injectors can have inconsistent or poor flow. Remember all it takes is a build up in one of the injectors and it won't close and that would explain your problem. First thing I would do is take out all the injectors and get them checked and clean. Not too expensive and won't hurt to do it anyway.

[Sydneykid]

When you saw flat spot you mean the spark is breaking down? Hence gapping the plugs right down? Do you have stock coil packs?

My guess is that your coil packs are either screwed or not strong enough for the power you are making. Hence the requirement to gap the plugs down so much. As a result you are not burning the fuel properly and its just bleeding down past the rings and there you have it, its in your oil.

My 2c.

Personally, I don't think so. That would show up in the WOT/full load dyno A/F ratios and they are a nice steady 12 to 1.

cheers

Edited September 11, 2006 by Sydneykid

[GunMetalR33]

Yea I also forgot to mention that I did play with launch control a while back which basically just retards the timing, hence stops the fuel from igniting in the cyclinder. Now most of this fuel ends up exploding in the zaust manifold or in the mufler but some of it would have ended up left in the cylinder???

I have gapped my current plug right out to .75 and am getting some irridiums with a pre set gap to .8 this week. So far with them gapped out I have hap no flat spotting and there is no fuel in the catch can.

I have bosch coil installed which I think are fine. I do how ever have spacers between my turbo and the zaust manifold. Now one of these spares had an inside diameter that was about 6-7 mil to small thus creating a huge restriction. I have grided that out and the spark issue seems to have gone and I gained a considderable amount of power.

So I will monitor the catch can for fuel with the new plugs in and see what happens, if there is still fuel buiding up the injectors with come out (suck a B*tch of a job ) and tested.

So they can test to see if the plugs are leaking can they?

Sorry for the long posts, it could turn out to be an interesting thread. I will keep everyone posted as to the results of the experiments

I am guessing I will be taking out those injectors pretty soon...

Edited September 11, 2006 by GunMetalR33

[GunMetalR33]

Do you guys think that I should be using plugs with a heat range of 6 or 7. The reason I ask is because I can only get irridiums 7's with a gap of 1.1. If I want a gap of .8 I have to go the iriway7's and they cost about $150!

I can get irridium 6's with a .8 gap for $100 delivered???

I am worried that the 6's might cause a little pre ignition and cause higher knock levels at 17-18 psi...