410 replies to this topic

[RX25SE]

..also,

 

Some live data off the O2 sensor when the car is misbehaving would be handy.

[LukeFranky]

The error code is P0171.

Funny you say KONG. The car has had an oil leak near the clutch for a while but it has recently leaked more.

It must be the crankcase breather now that it is mentioned. I thought it was a weird setup for a gearbox. Assumptions are the mother of all stuff ups. I'll get some more fittings and link it back to the intake manifold. I had previously just blocked it off on both ends and was only running the single line to the intake pipe.

I have two MAF's. I'll try switching them if the above doesn't work.

As for the clutch. It will need to be done either way. What is your suggestion? I'll be doing the noisy transfer bearing in the gearbox too. Any other gearbox bearings I should be looking at at the same time?

Thanks for all your help again. There's still hope for this car yet.

[LukeFranky]

I have an aftermarket silicone intake now in an attempt fix this as suggested. I also have a POD filter which has been on the car since I got it.

I must note. The engine is running a lot better now than it was. The error code used to appear on highway driving. Now it appears in town but haven't yet had it come up out of town. The conditions that trigger the light have basically reversed but I haven't done a lot of highway driving.

[RX25SE]

http://www.obd-codes.com/p0171

 

I'm still blaming the MAF, more so now I hear it's running a pod filter.

[LukeFranky]

The pod filter has its own MAF tube. Everything looks well designed and fits nicely. There's no dodgy looking adapters. The MAF bolts straight into the tube.

 

I have another OEM MAF which I'll try.

[TSG]

Is the pod filter oiled? B4's don't like that. Have you tried replacing the air filter and cleaning the oem MAF sensor (CRC MAF Sensor Cleaner). I'd reset the ecu (disconnect battery) after doing anything MAF related too.

[LukeFranky]

I don't believe it is oiled. I haven't looked closely. I have tried all those simple fixes but that was before I finished fixing other issues. I'll re-try those simple things soon. Cheers,

[RX25SE]

I have another OEM MAF which I'll try.

 

Are you sure it's a know good unit?

[LukeFranky]

Well I can't be certain. I asked the guy I bought it off for more details.

Anyway, I've lost that one way valve that went in where I put the blocker for the PCV. Anyone know where I can get one? Thanks

[Jimbo]

Edit: Didn't read properly. Doh!

I'm confused with whats going on with your breather lines. Are you able to take a pic of the back of your intake manifold where the main bunch of breathers are?

[Jimbo]

Just for your reference, I made up a quick diagram so you can see how the PCV plumbing should be at the back, just below your intake manifold. It's a bit crude but you should get the idea.

The "PCV" valve attached just under the throttle body to the intake manifold, is a basic ball valve which stops the crank case breather outlet from seeing pressurised air, when you're on boost.

Make sure it's plumbed so that the crank case outlet is always seeing vacuum. At idle, the crank case breather vapor will be drawn into the intake manifold via the PCV valve and also drawn via vacuum into the intact tract. When the manifold starts seeing boost, the PCV shuts to prevent the crank case seeing positive pressure. At this stage the vacuum is higher in the intake tract than idle so that accounts for the vacuum power lost while the PCV was drawing in vapor at the same time. It's pretty balanced.

Also, both cylinder heads have breather lines which merge and have their vapor drawn out purely by the intake tract.

[LukeFranky]

Wow. Thanks Jimbo.

See that crank case outlet. It is currently running to the intake tract. The line running from the crank case outlet to the intake manifold is blocked off. I thought I had the PCV valve but I lost it.

Everything else is intact.

[Jimbo]

Has the PCV valve itself been removed from it's thread in the bottom of the intake manifold?

Looks like this :

[LukeFranky]

Yes. That's the sucker I lost. I just replaced it with a brass stopper.

[Jimbo]

So your crank case breather is just a single line from the outlet, straight to the back of the intake tract?

I'm not entirely sure (waiting for someone else to chime in), but at idle, wouldn't the ECU be tuned to account for the volume of air coming from the crank breather with the PCV open?

[LukeFranky]

I think you hit the nail on the head. Light shows up most often after idling.