Power loss @ 4K

LordDigi · Apr 25, 2008

godchsr said:
... OK... The rear bolt on the CAS is gone but the front one is there.

You need to get that bolt put back in.

godchsr said:
... The tape is on there because one of the screws that hold the wiring hraness in is missing, must have been his BS way of replacing the screw.?.?.? ...

Picture would help out.

godchsr said:
... The gasket is also missing from the CAS. So there is oil leaking and getting on the CAS/wires too.

There's only a rubber O-ring seal for the CAS. If yours still has it, then replace it.

Like Green said, log for knock. But I would also check your base timing knowing that your CAS isn't properly secured.

godchsr · Apr 25, 2008

No data logger, no aftermarket gauge either. The stock gauge shows boost holding around 10 psi. SO there's no correlation to psi and power loss. I think there IS a correlation to crankcase boost and fuel cut. From what I have read of fuel cut this defines it almost perfectly.

godchsr · Apr 25, 2008

LordDigi said:
You need to get that bolt put back in.

Picture would help out.

There's only a rubber O-ring seal for the CAS. If yours still has it, then replace it.

Like Green said, log for knock. But I would also check your base timing knowing that your CAS isn't properly secured.

I'll snap a photo in a sec.

The CAS has NO seal at all. It is metal on metal mating... very ghetto

I'll check for knock but I have no way 'currently' of doing that. I had plans of getting DSMLink but if this turns out to be a major problem I'll just end up fixing the motor first.

godchsr · Apr 25, 2008

TSI@PSI said:
By looking at your compression #'s i really dont think it would only cause it at 4k only.

I'm not saying that the piston rings are the cause but somehow I am getting boost into the crankcase which is a big problem I think, right?

LordDigi · Apr 25, 2008

godchsr said:
... The CAS has NO seal at all. It is metal on metal mating... very ghetto ...

Get yourself a new seal.

godchsr said:
I'm not saying that the piston rings are the cause but somehow I am getting boost into the crankcase which is a big problem I think, right?

Not necessarily a BIG problem, but a good indication of a worn engine (valve seals, piston rings, etc.) Looks like a rebuild is in your near future.

godchsr · Apr 26, 2008

LordDigi said:
Get yourself a new seal.

Not necessarily a BIG problem, but a good indication of a worn engine (valve seals, piston rings, etc.) Looks like a rebuild is in your near future.

I'm glad you posted that because I totally forgot about the valve stem seals!!!! =)

Here's the thing: I bought this a week ago and the guy had a receipt for a rebuilt bottom end and fully built racing trannsmission (whatever that means???)
Anyway, so I was starting to get pissed thinking the guy faked the receipt BUT the head wasn't rebuilt and the head has almost 200K on it! =)

So that's good news because I have a feeling that the valve stem seals may be the real problem. Especially with that level of oil burn off I had after the compression test. Getting the oil to go 'up' through the piston rings would be much harder than it draining 'down' through the stem seals!

I am in a good mood now

Rebuilding the head should only take me a week at best and if I preorder all performance parts then it'll take even less time.

ANyway, back on track with the power loss. I took the advice above to try and prevent timing retard. I warmed the car up first and took it out, let me say IT DROVE AMAZING!!! In fact I can honestly say I truly enjoyed driving this car!

It was the first time in my life I have ever driven a 4 cylinder turbo AND my first time driving an AWD car. It was great and I can see why you guys love these cars so much!!! hahaha

I am just very excited, the car pulled decent in 1st but when you hit second and third it's mildly creepy because that dang thing just hooked the tires in and pulls straight! In my 300zx TT I would NEVER have gotten the tires to hook that well in ANY gear!

I'm rambling... enough said. Thanks guys, I'll keep you updated in this thread as I continue to diagnose this problem but I think it's clear the ECM is going into some form of limp mode or fuel cut. If there are any more suggestions I welcome them! Thanks

godchsr · Apr 28, 2008

Today I had a long stretch of fuel cut for maybe 5 minutes of driving. It was pissing me off so I started stomping the pedal in frustration and out of nowhere it was driving perfect again... This car is freakin weird... any thoughts as to why that would change something?

greenstreak · Apr 28, 2008

I have my doubts as to whether you are experiencing fuel cut or not.

If you indeed are you need to do a boost leak test. The MAS would have to be seeing elevated levels of airflow to trigger fuel cut with your minimal mods.

godchsr · Apr 28, 2008

Same scenario as before, getting lots of boost in the crankcase (PCV is fine, blow by is assumed at this point???)

I am certain that the MAS is getting high reading because of the loss of 'used' air. Literally the air gushes out of the dipstick tube. The intake system is still under load but not 100% of the 'read' are is being 'used'. I'd make a guess that it's more like 90% of read are is used. (I have no way to measure that without a wideband though)

My resolve at this point is to purchase a wideband and determine my AFR at all RPMs. I'll also redo the compression test to confirm good or bad compression. Replace the rings if necessary and go ahead and do the head gasket and timing belt while I'm at it.

The block, Head and Transmission (verified) were all rebuilt so I am skepticle at this point of the quality build or my understanding of other possibilities for blowby.

LordDigi · Apr 28, 2008

You need to do a leak down test to verify where your blowby is happening.

godchsr · Apr 28, 2008

I know... I'm in the process of moving, so I'll end up doing it in a week probably once the new garage is set up again. 2 Car garage double deep!

LordDigi · Apr 28, 2008

Nice! Keep us updated.

Power loss @ 4K

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