Overfueling -> Bore Wash -> Blow By -> Crankcase Pressurisati

[smckeown 1]

I have been doing some research in this area and do expect the worst with my engine.

 

It seems the symptom of crankcase pressure can be the result of blow by, which can be the result of bore wash, which can be caused by overfueling.

 

What i'm confused about, is that if you have a car mapped and you have an AFR readout that proves you are not overfueling, then how can this situation happen? I have read that a sticking injector can cause it, but as I had them reconditioned before hand, it would be pretty bad luck for that to happen afterwards right ? I suppose having then ANSU checked again would show a sticky injector, or even better using 4 milk bottles and the injector pulsing option on the KMS ECU to check the 4 injectors are squirting all the same would also be a good test ?

 

Is there anything else than can case issues i nthis area ?

 

I have seen that on one occasiona after mapping that the lambda closed loop system has been switched on accidentaly, Steve Greenald said this has happened to him since. Could a short spell woth no lambda connected and lambda control switched on cause such a bad overfueling to wipe out my rings/bores to quickly (to be confirmed obviously)

 

I know it has been overfueling because after anglesey the oil was chjanged and it was full of fuel! So this could be the reason of the eventual crankcase pressure ?

 

discuss

 

Sean

[B1ack_Mi16 67]

Don't you have an AFR meter/gauge installed in your car so you can keep an eye on the AFR while driving?

 

I've got one from Innovate Motorsports and it's certainly worth its' money!

http://www.innovatemotorsports.com/products/xd16.php

 

You should get a leak-down test on the engine I think, and take it from there.

[pdd144c 0]

You have the same symptons as my TT had... Have you played with the map at all? If so you could of changed it by mistake?

[smckeown 1]

Don't you have an AFR meter/gauge installed in your car so you can keep an eye on the AFR while driving?

 

I've got one from Innovate Motorsports and it's certainly worth its' money!

http://www.innovatemotorsports.com/products/xd16.php

 

You should get a leak-down test on the engine I think, and take it from there.

 

I'll have one shortly as i'm in o nthe VEMS group buy

 

des-developments will be doing the full tests, i'm just intereated in the causes of this area and how the hell it could have happened to my brand new engine so quickly ?

[Faz85 0]

just a thought... could the PCV system is at fault? have you checked your breather hoses, if you've got a split then there might be no pressure to suck out the blow-by gas.

 

also, if your engine has a PCV valve, that might be at fault...and of course worst case scenario would be blown rings (seems unlikely to me)

 

Faraz

[smckeown 1]

You have the same symptons as my TT had... Have you played with the map at all? If so you could of changed it by mistake?

 

Just checked it, has not changed since originally mapped. So on that basis, how on earth could it be overfueling?

[welshpug 1,657]

have you changed the filters at all?

 

does it run rich on cold starts?

[pdd144c 0]

Perhaps the final map is not the same as the one that was loaded when the read out was taken?! Or a faulty temp sensor?!

[welshpug 1,657]

the air filter I mean, less air coming in = running rich maybe?

[smckeown 1]

Perhaps the final map is not the same as the one that was loaded when the read out was taken?! Or a faulty temp sensor?!

 

im pretty sure temp sensor is fine, i'll take it for a drive tom with logging on.

 

not sure what your saying in your first sentence ?

 

 

the air filter I mean, less air coming in = running rich maybe?

 

yes after running in and mapping the oil filter was changed and oil was 100% changed (sump, accusum, oil cooler) and then again after anglesey the oil was changed (As it was full of petrol)

[smckeown 1]

have you changed the filters at all?

 

does it run rich on cold starts?

 

no airfilter the same, no idea on cold starts, doesnt really get cold started

[Tony_205 1]

Know the feeling mate, im currently haveing the same problem with my sons GTi. As a result of filling the tank with diesel though

 

Interesting thread as i dont know what to do, change injectors or what ....

[Robsbc 0 1 Cars]

no airfilter the same, no idea on cold starts, doesnt really get cold started

 

of course it's cold started unless you pre-heat the oil first...

[smckeown 1]

of course it's cold started unless you pre-heat the oil first...

 

i assume a cold start is being stuck outside all night and started first thing in the moring. otherwise whats the point of the question ? who heats their oil up ?

[Robsbc 0 1 Cars]

i assume a cold start is being stuck outside all night and started first thing in the moring. otherwise whats the point of the question ? who heats their oil up ?

 

In the garage during this time ur car water temp will be around 0-5degrees..that's still cold

[Banjo 1]

Get a leak down/compression test done to see if its the rings no?

Tony 205 why not just drain the derv fill up with petrol and drive? It's only oil at the end of the day so will just smoke a bit, different case if it was the other way round.

[Sandy 191]

Surplus fuelling might come from cold starts (of any kind!), throttle pump effect, fuel drop out under certain conditions, mixture homogenisation problems under certain conditions, or the oil could contain fuel from blow by due to poor ring seal with high CR.

Edited December 9, 2006 by sandy309

[smckeown 1]

Yeah i'm thinking it may not necessarily be overfueling causing blowby via bore wash. It could have been a ring sealing problem from the beginning ? Either by incorrectly honed liners, liners too much wear to begin with or incorrect rings. But to be honest I can't see puma (even though i'm not on his xmas list) getting this wrong or doing anything of the like intentionally.

 

So today i'll check injectors and wet and dry compression test.

I'll then take it for a drive and film the oil pressure and water temp when it's driving .

 

Can't think of anything else useful i canm do myself before it gets taken to bit by DES in a few weeks.

 

It's interesting to learn more about this stuff.

[smckeown 1]

The good news is (there has to be some) is that i'm convinced it was suffering crankcase pressurisation when it was being mapped, and that was making the torque drop off so quickly at high revs. I was getting a camcover leak during the RR. SO ever cloud has a silver lining yeah ......

 

I'm thinking this because when I was getting it noise tested at goodwood the other day, it was very hard to maintain revs over 5k. You'd maintain a certain amount of throttle and the revs were just dying.

[Banjo 1]

How did you run it in? If it was gently or it idle'd a lot then that could be your problem, needs full throttle to bed the rings in..

[smckeown 1]

i've just read a post saying running a wilder cam usually means the need to run more fuel.

 

Well the fuel maps between the old cam and new cam are identical But that would indicate it would run lean not rich?

[smckeown 1]

How did you run it in? If it was gently or it idle'd a lot then that could be your problem, needs full throttle to bed the rings in..

 

Do you think i would spend all this money and go through the engine build year of hell to so something as stupid as that ? no I paid good money for SGR to run the engine in at goodwood race circuit using the kms lambda probe to try and get the map as good as possible as early as possible during the run in period. He spent half a day gently running in the engine there. The only main time it ran before that was when it was running in the cam initially, but thats not at idle as you prob know

[smckeown 1]

Here are the plugs...running rich you think ?

 

 

just done a compression test and got the following:

 

cold engine

all plugs removed

throttle on

6 turns per test

 

cylinder....1.....2.....3.....4

dry.........210...205...200...205

wet........210.....210....200....215

 

Just read puma's site and he says the rate of compression raising on the gauge is important, so i'll just go and film each one...

 

I also tried to test the injectors, but I damaged one of the rubber seals so need to replace that before i can finish the test

 

[smckeown 1]

I've filmed the compression test HERE 12mb

 

Cylinder 4(flywheel end) seems to have an issue

 

My synopsis:

 

Cylinder 4

First to 60 and 150

Bizarelly seems to lose all compression and back to 0

Then climbs to 180 after 3 strokes

Then climbs slowly to 210 and stays there after more strokes

 

Cylinder 3

Starts at 120

Then jumps to 170

Then climbs steadily to 210

Then stays there with more strokes

 

Cylinder 2

same as 3

 

Cylinder 1

same as 2

[smckeown 1]

Here's a question...If the new wilder cam that went in was making less power, if the fuel map was left the same as with the first cam on more power) then wouldnt that make it rich if you didnt alter the fueling map ?

 

I'm going to contact mikeanics because there's no AFR on his graphs. Whereas on the inital mapping session there is and all was well