1990 911 carerra 4 964 please help

[jeffery1982]

hello my name is jeff, my father has a 1990 porsche 911 964 awd, he plucked the engine to have the rings replaced at an engine shop, put the engine back in, it starts hard and when it does start its burning ritch, it wants to stall, it sputters bad while driving, when you turn the ignition off then back on quick "while driving" it fires right back up then starts to sputter again we did this about 50 times just to get it back to the garage, anyone have any ideas what this might be, he also removed the heater blower motor in the engine compartment and installed a carbon fiber pipe in its place which is a aftermarket piece and also the second to last muffler was removed i think its a muffler anyways this car is non turbo

[rbogh901]

Are the oxygen sensor and CHT properly connected back up?
Vacuum leak?

[TMc993]

Originally Posted by rbogh901

Are the oxygen sensor and CHT properly connected back up?
Vacuum leak?

+1...He needs to get a shop manual and go through all of the sensors, vacuum tubes etc and make sure everything is correctly connected.

[B. Elliott]

A vacuum leak will cause the engine to lean out rather than run rich. I would first check your ICV unit. When mine went south it had the exact same symptoms as yours.

With the engine running, disconnect the plug to the ICV and see what happens. If it dies, the unit is working fine. If it continues to run the same way, bad unit.

[lightingguy]

Could it be the drive belt to the secondary distributor? With the engine idling pull the center wire to the primary (right hand) distributor. If the engine stops your secondary distributor probably isn't working.