clali

Hello

Last night my wife started the Porsche 964 1990.

After a big pow;

1-A small amount of smoke
2- no oil on the ground
3-an intake distributor dismantle! See picture

Those somebodies have experience with the cause of this disaster
The somebody has an idea of the repair?
FYI, I was planning to change the rotor and spark plug next week


Thanks for your Help
clali

Vandit

Possibly a leaky injector or failing fuel pressure regulator diaphragm.

tdiquattro

may be talking rubbish but - dizzy belt snapped and backfire through intake?
Or it just came loose over time, but looks like there must have been some pressure to pop all those rubbers off.

alexjc4

Yes that has backfired through the inlet manifold. Fuel system issue seems likely.

Vandit

Broken 2nd distributor belt seems plausible too. Check that.

Robbrizzle

I've had a snapped dizzy belt do this but I've also had a clogged ISV do similar. Both as as a result of a backfire.
Loosen the large jubilee clips round the throttle body to get the intake plenums back together then check both.
On mine, the ISV needed both a flush with carb cleaner internally and contact cleaner on the electrical connections, I also replaced the crimped clips on the hoses with jubilee clips and so far so good.

clali

Thanks foryour Help


I have reassemblethe air inlet intake plenums
The first think I checked was the 2nd distributor belt.
Yes it was effectively broke.


By the sametime I try to check fuel pressure regulator diaphragm, but I didn’t really know how or what to check on this difficult part to reach.
I did notcheck the ISV yet.


I have readother post regarding distributor belt snap and one of them was mentioning that problemmay have also damaged a cylinder or two...


Is there any simple way to verify this potential problem?


I plant to start the motor (once only) with only one active cap distributor .Is there any contraindicationto do this ?


Again thanks a lot for your comments it is really helpful

Vandit

For the FPR, follow the vacuum line from the FPR to the center of the intake plenum. Be sure that this line is easily removable at the plenum. Now turn on your car. Once the car is running, disconnect the vacuum line at the plenum and watch it for a minute or two and see if it spits out gasoline through the line. If it does, then the FPR is on its way out.