1983 Lux starting issue

[bazbarnett944]

Hello

My 1983 944 Lux is struggling to start and need to know what to replace to solve the problem.

It starts every time (engine fires into life) but then dies. Sometimes it’s 6 or 7 times before it finally ‘catches’ and stays running. Am draining the battery (new) quite a lot so if I come to start the car again later that day then it struggles.

Recently had Oil filter / oil change / air filter, new spark plugs, ht leads, distributor cap. So car is running and driving very well (purring, actually) when it is running. Frustrating about the starting it up though.

Any suggestions and recommendations would be gratefully received.

Thanks in advance

??

 

[Sandspider]

DME relay?

 

[bmnelsc]

DME relay is definite possibility with it cutting off fuel when switching from start mode to run mode. I wouldn't expect the relay to "heal" itself after a few attempts however. You don't say if this is cold or hot start, hard to start after a short stop, etc. So could be fuel issue. If hard to start from hot or after a short stop it is often a vapor lock due to check valve not holding pressure. If cold start also it could be pressure regulator not holding enough to build required system pressure quickly which might explain why it finally does after 6 or 7 attempts and runs fine after. If cold start ONLY then you need to check for cold start enrichment - after if "runs" 6 or 7 times it might have enough heat to run without extra fuel ...I'm assuming its not very cold there yet

 

[bazbarnett944]

DME relay is definite possibility with it cutting off fuel when switching from start mode to run mode. I wouldn't expect the relay to "heal" itself after a few attempts however. You don't say if this is cold or hot start, hard to start after a short stop, etc. So could be fuel issue. If hard to start from hot or after a short stop it is often a vapor lock due to check valve not holding pressure. If cold start also it could be pressure regulator not holding enough to build required system pressure quickly which might explain why it finally does after 6 or 7 attempts and runs fine after. If cold start ONLY then you need to check for cold start enrichment - after if "runs" 6 or 7 times it might have enough heat to run without extra fuel ...I'm assuming its not very cold there yet

Many thanks for the above information.. very helpful. It’s mainly cold start, would be grateful then how I go about checking for cold start enrichment or what I need to replace. Thank you

 

[Waylander]

Blue topped Temp Sensor at the front of the engine, tells the ECU how cold it is, so the ecu can run the cold start map