I don't think it's a fueling issue. It just can't be, you've covered basically every base. New injectors, new loom, new ecu, cas, ptu, etc, etc...so I'd put money on a major blockage on the passanger side intake pipes near the turbo. Perhaps a rag they didn't remove before reconnecting pipes. Pull the intake tract apart on the offending bank. This will cause all your symptoms, the reason it will run at higher throttle openings is that it's pulling air across the balance tube, but you need alot of throttle to do it.
But it still does the same thing with the AFM unplugged - and nothing in front of the throttle bodies....we should at least be able to get it to idle like that We are able to blow air thru the throttle body and feel it coming out of each spark plug hole in turn on that bank as you turn it over, so no major blockages in the plenum either Any other reasons the car would be trying to breathe thru the balance bar that hard that its disrupting one bank?
Injectors Are you certain it's not 2 or 3 dud injectors pumping way too much fuel and drowning the spark?
100% sure - had the injectors checked and cleaned by Dwight - all flow within 1cc of each other, and also swapped to a spare rail and injectors from my parts car, with no change
No because the idle feeder attaches lower down the intake tract, pre turbo actually. at idle there is little air being pulled past the TB's. Try it, pull apart the intake piping around the turbo and intercoolers. It's not a problem with too much fuel, it's not enough air, so now you need to find out why. If it was a misinterpretation by the AFM then all cylinders would be flooding. I would have looked at a damaged loom shorting out that bank and have the injectors on 100%, but you've got a new loom in there. Same with the ecu. So in my books you need to pull the intake tubing apart as your next step.
I agree with Andy You've double or triple checked everything else ... not the first time a mere rag caused so much tearing-of-hair-out.
Have now checked both intake tracts - both clear. IACV made no difference as expected - but as an experiment we blocked the balance bar off from the plenum with tape - and it runs better - still not 100%, but much better.... Will hold 5-6 cylinders under light throttle openings. We are getting positive boost under a decent rev - enough to move the intake pipes if the clamps aren't done up so turbos seem ok as well. Help!
what about the lower plenum...when you had the upper plenum off did you check the gasket between the lower plenum and head? kinda clutching at straws here tho... The only things left is that the blockage has now been chewed by the turbo and currently resides in there, the blockage is actually in the exhaust side, or the intake cam timing is way off, take the timing covers off and have a quick squize at the marks. Does it drive? I mean what happens when you really load up the boost. (stock boost)??
Lower plenum has brand new gaskets on it - all seemed to be seated correctly.... Currently only has the dumps on it, so theres no blockage on the exhaust side - neighbours can confirm that We might just pull the cam covers off again next - the good compression sort of ruled it out, but what else can it be? It does try to run when you load it up - misses a bit and blows a lot of black out of the RH bank, but does run better..... Best we have had it running is with the balance bar blocked - there must be something in that, if the cam timing is out - maybe we are getting reversion with valves still open at the wrong time allowing compression to blow back into the plenum, but this should be ruled out by the compression test that seemed fine
When you say RH bank you mean passenger side yeah? When you said you checked the intake tracts, did you check both sides? I just remembered that actual intake route for each bank is on the opposite side as the plenum feeds opposite banks. ie, so if it's the passenger side bank of cylinders not firing then the actual air feed is on the drivers side. So if you were looking for a blockage then it would be on the other side of the engine. Just a thought.
No - RH as in Drivers side..... Did check the both tracts, its the runners from the Drivers side bank up to the LH side of the plenum which is very wet with fuel..... You can also see the marks on the ground where we had it running this afternoon - there is a black stain on the concrete under the RH dump, the LH side is pretty clean still
damn...it's a curly one. Try this. Disconnect the AFM from the loom. Then remove the TB pipes from the TB's. Start the engine (you'll need some throttle as well, it doesn't like this much). How does it run? You may want to disconnect the intake pipe from the IACV as well to give it an open tube. Is it still rich as all hell? If it is then I'm wrong and it's fuel related, you may be grounding out that bank of injectors somehow causing them to stay open permentately.
Your not wrong there Have tried that - it runs just the same as with it all hooked up.....RH bank comes in on a rev/under load (as much as you can get up to 2000rpm where it cuts out) Still rich as.... Thats part of why we picked it as being fuel related at first, but surely we have eliminated that by now? 2 looms with the same fault, 2 fuel rails? Everything seems to be working alright - last time we had the upper plenum off to change the rail, spinning the CAS they all seem to be firing sequentially as you would expect.... It can only be cam timing surely...its all thats left - everything else has been swapped :bash:
well if you intake cam was advanced far enough then you'd have the valve open during the compression stroke pushing fuel back into the plenum...but I can't see how it would be causing the super rich running...meh, it could be worth looking at...you've tried everything else dude.
How about the VCT solenoid? If that was stuck on, it would explain the terrible running down low which should clean up around 2K+ RPM which is when they are supposed to be opening anyway? James, Pls see my email reply
Would it have that much of an impact? It's only 3 degrees isn't it? Easy enough to test unplug the bastards and see if it cleans up, although it could be mechanically seized, and thats different again. Damn, I wish I was in Brisvegas, I'd love to tackle this one.
