Cold start, won't start, warm start will - issue 3.2
 

Over the last few months, my stock 3.2 has exhibited off and on, but slowly getting worse cold starts - after a week or two of sitting. Today, it wouldn't fire at all after several minutes of trying and the car actually starting to shake(?) while turning the engine over. In the past, once the car starts it would run and restart fine. I don't smell any gas around, and am wondering if I should try some fuel pump checks or what - and not sure what those would be. I'm not a mechanic by any stretch, and would appreciate any guidance. I have a spare DME but I've always heard they just go bad all at once, so it doesn't seem this progressive problem fits?

Probably the CHTS, Do you have the updated one or is it OEM?

I've only owned the car a few years, so I'm not sure. Is there any way to check it?

Download the PAG katalog for 84-86 911's

CHTS is the cylinder head temperature sensor. You can remove the huge "banana like" black plastic heater tube then you will see the mounting brackets for three sensors, the on top is the sensor connector it will white ( yellowed out due to heat ) take a pic and we can tell if it is OEM or updated.

The sensor end is screwed into the #3 cylinder.

Jim

Just to close out the thread and for any future searches, I changed out the DME and car started right up and ran great all weekend. I had always heard about those units going from fine to dead, but this one gave some warning, with previous hard starting.

Did you change the DME relay or the entire DME? There is a big difference in price.

Sorry, relay.