Porsche Enthusiasts Club Forum

My newly acquired 84 944 that I originally bought for parts but am now revamping/restoring has a fair few issues, some of which (interior) are in a different topic.
I bought it with an electrical gremlin the previous owner could not find and was wondering if anyone can help
It will start but is rough, when I try to put load on the engine it struggles and cuts out (I did manage to move it into the garage though).
The previous owner said the results of the compression test were good (No reason to doubt), I did pop some new plugs on and stripped and cleaned the leads and it will now rev whilst in neutral (Auto box) which is an improvement! I can only think that is a fuel or ignition issue but am a bit lost as i am a mechanical not electrical type person (time served welder as well ).
Any help much appreciated

AFM is suspect but not straightforward to test. easiest way is a swap with a known good unit with the same number.

Temperature sensor is suspect - dead easy to test you need a multimeter and a kettle.

fuel pressure regulator might be suspect. pressure gauge is a good thing to have in the tool box.

plusgs/cap/arm/leads always help, as does a good service.

Are you local to Warwick? I have an ignition tester which can help in ruling out the ignition system .

No in Scotland but thanks for the offer

If you leave it running and stand at the back of the car, do your eyes sting?

Any smoke from the exhaust? such as white, blue, grey or black, either at idle or when you try to rev it?

Quite a hard one to diagnose remotely and much easier to diagnose in person..

Do you know any mechanics who might have a leakdown tester, fuel pressure tester and a compression tester?

Have you joined the club and popped along to a local meeting? there may be someone else with these tools, or may even have another pre 86/87 944 to lend you an airflow meter, DME etc from.

I have a compression tester and a friend who worked as a mechanic at a specialist selling Porsches in Malvern, he has an ignition tester as well, I think I will get him round. Thanks for the reply

It does not appear smoky in any way. I am in the club but have not been to any meetings as I am enjoying my first decent stretch of time in the UK for 18 months, I must get along to one.

I think it is sorted Followed all the advice and tested the AFM, temp sensor etc and all proved good. Before I started to look at the fuel system I thought I would just try and swap over the DME unit and later type AFM from an 86 car that I also have, hey presto it runs fine. Now the 86 car may never go back on the road To me this points to the actual DME unit itself and my question if anyone can help is, do I put the old AFM back in and source an early DME unit or is it ok to leave as it is? bearing in mind the engine will be out over the winter to repaint the engine bay as part of a bigger revamp. Any advice much appreciated guys.

Augment automotive fix DME's. They also make their own modernised version which they install with a modern MAF. Replace your failing parts and get a boost to perfomance to boot!

When I have saved enough pennies that is what I will be doing .

I had never heard of them until you mentioned them, an interesting site