high pressure during cut off

[mgrover]

new maf in, the STFT are around 20% with the reset of adaptations so I doubt it was the MAF but at least I can forget about it. Supposedly the vacuum pipe going from PCV to the SC leaks air somehow. We've just had snow, so can't do too much.

BUT

This all started when I was changing the thermostat, I wonder if when I removed the plastic intake boot it's cause something near the throttle body to start leaking. So I'll tear down the intake again and check the gaskets and replace the PCV pipe going to SC with a fuel hose and jubilee clips.

[mgrover]

So defo think it's the pcv pipe since the bit that connects to the throttle housing just before the supercharger is covered in oil , so most likely the leak. Am going to try to replace the orings to see if that'll fix it.

[mgrover]

changed the sucker, my trims seem to now be in the 10% region for one bank and 8% for the other.

[LPGC]

Very good. I thought you'd ruled out this sort of vac leak problem earlier with careful inspection of plumbing and smoke tests lol... But the PCV on these engines can be a pain with the brittle plastic clip-on pipes and the seal on the drivers side cam cover. Result though!

[mgrover]

Supposedly smoke tests don't show this minute leak. Not sure how not but I wanted to be sure. Also seems like made no diff. It's back at 18% for Bank 1 and 10% for Bank 2.

Am outta ideas now tbh. Constant smoke tests, the intake has been reassembled more times than I can remember with fresh gaskets. Fresh seals for the fuel injectors. I honestly dunno anymore

Although given the throttle housing was covered in oil, and down the bellhouse of the gearbox is covered in oil I gotta assume it was leaking

Edit, I just realised something, the fuel pressure sensor/regulator vacuum line isn't current plugged into the back of the charger like its supposed to be but instead plugged into where the supercharger bypass vacuum line goes. I need to swap them around

Edit the logic above is the fuel sensor needs to go to the charger directly while the bypass valve needs to go to the throttle housing am hoping that might explain some of the issues

Also my reducers are plugged into a vacuum port coming off the manifold. But am not sure what originally went there before the reducers since nothing else is also being plugged into that?

Also at the back of the throttle housing theres two vacuum lines, the one that goes to the pcv and one next to it that I have no real idea where it goes

another edit: ive swapped them round to the correct way then jubileee clipped every vacuum pipe in sight.

[mgrover]

been driving on petrol for a bit to let the trims settle before i ruin them with lpg.



not quite sure why its all over the place anymore. theres defo the difference between 2 banks. but the difference between 1200-1700 is ridic, from 18% to 5?