Porsche Enthusiasts Club Forum

Still battling with my 944S. With breather connected and I blip the throttle the engine revs then falls quickly below tickover and stalls. If I leave breather disconnected from air intake allowing air to be pulled in problem goes away. Smells very rich from the exhaust. I suspect someone has tinkered somewhere in the past. Oil breather was intentionally disconnected, with intake left to suck an air leak. Any ideas anyone?

normally if the breather was disconnected I would expect it to stall rather than the other way around. Does the exhaust smell like its running rich once everything is warmed up?
I would check the air filter (blocked?) all the small vacuum pipes (lots off and all need to be secure), the idle control valve, the air mass sensor unit and the throttle body. Have a look at Clarkes Garage web site its full of info for DIY checking and repairing of these parts.

Thanks for the feedback. It does smell rich even when warm. Air filter is fine. MAF stripped and adjusted the wiper onto new tracks to try and clear another problem of hesitation at part throttle. Noted someone has been in here before and a pen mark on the spring adjustment for the barn door! I know air leaks are a common problem but all indicate rich I think. The idle valve looks a pain to get off, assume I would have to pull the inlet manifold? Wondered about fuel pressure before I try someone with a CO analyser!

just a thought and easyish to try - with the engine running disconnect each fuel injector in turn. If the injector is good the engine will run rough and struggle, If one of them is leaking it won't make any difference to how the engine is running when you isolate it.

Hi, tried disconnecting injectors. Even engine drops evenly each time each is disconnected. New plugs and checked temperature sensor OK. I'm still thinking around the MAF and spring adjustment have you or anyone tried this?

tricky - fuel pressure regulators on the fuel bar? have to check the fuel pressures next I think

Thanks, will check before delving deeper.

IMO it will be down to severe MAF maladjustment or a failing FPR. Where in the country are you?

I had my doubts about the MAF, thought about adjusting the spring tension until basically the problem goes away (if it does!). Bit of a gamble though as the mixture could end up anywhere.Anyone know a basic start point? Will go for fuel pressure check this weekend first as easy test. Plug colour doesn't look unhealthy though. All a challenge. I'm in Cheshire by the way.