MY04 Liberty GT - FrankenStien - EOI welcome / FS

[dr20t]

You must've edited your post before I posted mine as I didn't see the stoich part

Yes - stoich is short for stoichiometric which is the most complete burn of an air fuel mix

Its really a conversion from lamda which is different for different fuels but you already know that you little science geek

[Deep Heat]

You really won't believe me - but I had a very very weird feeling you would be the first to reply to this update with something deviant and twisted

Lol

You are a real mess

You can come and watch. And service me while I service the car

I wasn't joking. PM me your address.

Yes - stoich is short for stoichiometric which is the most complete burn of an air fuel mix

Its really a conversion from lamda which is different for different fuels but you already know that you little science geek

So you aren't just a pretty face.

[KiDo_Tuning]

Let me come over to watch you fix shit so I can have memories to jerk over later.

You really won't believe me - but I had a very very weird feeling you would be the first to reply to this update with something deviant and twisted

Lol

You are a real mess

You can come and watch. And service me while I service the car

What is Rome supposed to be doing during this? Oh wait... watching

[Deep Heat]

Meat in the sandwich.

[Rome_BRZ]

Stop fucking spending money on your car you nut

[Deep Heat]

Stop fucking spending money on your car you nut

[dr20t]

So a day of mixed success

Removed the kw's and replaced with bilsteins. I'm at like 4wd spec now.

I must say the difference in comfort is probably in favour of the kw's, which tells you just how good they actually are for a street car. Even though the bilsteins are sitting higher, there is bugger all difference in their ride. The handling is obviously different but acceptable with the billies, although you lose that feel of the road which is so assuring with the kw's.

Changed the right front hub which was causing a massive and annoying sound. So all good there now.

Replaced every gasket from head to dump pipe and sad to say I still have a slight exhaust leak. I'm thinking its the up pipe adapter to my twist mount setup which may have a hairline crack. A shame really cos I wish I could've tested that while everything was out as its a royal pain to remove it all again.

Might have some luck with someone being able to weld it on the car if its on a hoist so will see.

Oil and filter change was good and smack on 3000kms.

Ran out of time to change plugs but did get my hands on 12 of them which will last a good 45000kms.

Hopefully get to change them tomorrow morning, as I'm still having that misfire on spool up. Its either plugs or the exhaust leak causing this lean out/ misfire. I'm sure of it.

Mick

[Deep Heat]

I am very drunk but i'm confiedent you can't fit 12 plugs to you car.

[alexeiwoody]

I am very drunk but i'm confiedent you can't fit 12 plugs to you car.

They're not for the car

[dr20t]

I am very drunk but i'm confiedent you can't fit 12 plugs to you car.

They're not for the car

4 for the car, 8 for deep heat aka twinkle toes aka dangle-berries

[Deep Heat]

Love you too bae.

[dr20t]

Putting this out there to gauge thought from those in the know:

With all gaskets changed yesterday from header to dump pipe, I thought about why its still misfiring/ leaning out when it hits 1-2psi.

Checked fuel pressure today at that rev/ load/ boost and its fine. Jumps up to 45psi with 1psi of boost then starts to misfire but fuel pressure holds solid. This was done by loading up the engine in first gear on the brakes while stationary.

So I thought maybe my long term fuel trims were taking too long to learn back. Flashed a new tune (same as the one that was in there but with the same timing table around the spool up zone as Matt's dyno tune in May). This basically just added back the timing I had taken out of the map when this issue started happening.

Seems to have made it better but it's still slightly missing on spool up and leaning out. Alot better though

Before I go and add more timing I want some thoughts if possible:

1. I first noticed this happening on the same day / just after I welded the slip joint on the headers up. I could be wrong here though as it may have been happening before but because it wasnt my daily at the time, when I was driving it I was generally banging through the gears and not sitting at 2000-2500rpm in 3rd/4th gear - so maybe the issue wasnt showing and only showed cos I've been daily driving it again the last few weeks and at the time I did the headers cos I was looking for the difference in spool up.

2. With the above said, if indeed the headers are now better (ie not leaking anymore) then wouldn't the engine need LESS timing? I'm sure I've got this right. The less efficient an engine is (less VE) then the more timing it needs. By welding the slip joints, this should effectively make the turbo/ engine more efficient at the same revs/ load, as it will flow more air and not be leaking. In turn, it should make boost earlier (ie boost threshold / 1 psi should come in at a couple hundred rpm sooner with the headers not leaking anymore).

If this is the case, why is it running better with MORE timing in that region (1.6 - 2.05 load range, 1800-2800rpm tables). Between 2-4 degrees more timing back in there now in those tables.

More timing generally means more cylinder pressure, which means leaner burn mixture for the same amount of fuel. But in this instance its helped richen it up slightly. I'm really puzzled on this one

On another note - if my plugs are indeed fouled (which I will know soon), then would fouled plugs cause the misfire only at 1-2psi at that low to medium load range? Once at 5psi and above, its fine. So the plugs aren't fouled up enough to cause issues up high.

Is it possible that fouled plugs only cause this misfire at low load low boost? Never heard of it before as bad plugs usually show themselves higher in the rev range and higher boost. Like I said mine are fine at that part of the map, no misfiring or lean out at all. Its just on spool up at low revs/ low to medium load.

Am I wasting my time changing plugs in the hope of fixing this issue? In my mind I feel like the answer to this is now "yes".

Would bad coils do the same thing? Ie only cause issue at low load/ boost but run fine up top and high boost?

Could it be an intake vacuum / boost leak?

Dirty fuel filter (unlikely I think but worth a shot if the above dont work)??

Got me stumped so any advice appreciated

Mick

[dr20t]

Another thing I'm thinking is bad 02 sensor causing issues from closed loop to open loop transition?

I dunno just clutching at straws right now

Any other thoughts?

Maybe the added timing has helped mask the real issue? Would more timing assist in masking a vacuum / boost leak? I would think it should be the reverse unless someone tells me otherwise

[bigBADbenny]

How are the coilpacks? Need a spare set for testing?

[dr20t]

How are the coilpacks? Need a spare set for testing?

Thanks for the offer Benny - I have a spare set from my old engine but will let you know

Problem is mine are spec c coils which are higher voltage and different dwell time. So unless the coil is completely munted I don't think it will make a difference. Maybe worth a try.

Importantly though - do you think a bad coil could cause this only at 1-2psi / low revs and not higher up in revs and boost?

I always thought if the coil was failing at that point then it would continue to cause a misfire higher up?

Maybe it is doing it, but because the motor revs so fast when on boost that its being hidden, and the e85 is masking any knock. Thoughts?