HELP! 986S Problem - Page 1 - Boxster/Cayman - PistonHeads UK

HI all, looking to see if anyone has had similar. Few months back, on a hot summers day, I had parked up in a shopping mall multistory to go for some lunch and some shopping. Came back to the car about 3 hours later and the car refused to start. After about 5 minutes of persuading it fired up. During this time the engine was turning over just didn't seem to want to fire up. Thinking that this might just have been a random occurrence I proceeded to drive home via the supermarket. Went in to get my shopping and then came back out, same again, the car was struggling to start. After a bit of swearing etc it started up again. Got the car home and decided that I'd try the car again tomorrow morning to get to work and if it failed again I could call the AA out. Car ran perfectly again for the next few months until a few weeks ago. Very hot summers day, driving home and it just cut out. Managed to nurse it out of traffics way and had the car picked up by a local recovery. While waiting for the local recovery I tried the car a couple of times and like previously it turned over but wouldn't fire up. Being afraid to burn out the starter I stopped and just waited to be rescued. Car gets recovered to my local trusted garage. A few days later I drop him a message to see if the car arrived fine and if he's had a chance to look at it. He says that the car fired up straight away in the morning and has no error codes. Currently waiting to see if he's got any recommendations or ideas of what may be wrong. Just posting on here to see if anyone has had similar experience or any idea what might be causing this. TLDR - Car doesn't like to restart when hot out 1 day. Few months later on a hot day car decides to cut out and not restart. Next day when weather is a bit colder the car starts no problem. What's going on?

I had something similar on my 996, which was a failing Fuel Pump Relay. Replaced that (simple plug in job and cost about £12!) and it's been fine since. Could be that, could be the fuel pump itself, could be any number of other things, but I was lucky that one of the first things I tried sorted it.

I did think fuelling issue for a bit. But would that have manifested itself on hot days only? Or maybe the hot day was just a coincidence? I don't really mind throwing some parts at it to get it sorted (within reason), my bigger worry is that because it's an intermittent issue I may be left stranded again. Was OK this time as I managed use the momentum to get it in a place where it wasn't disrupting the flow of traffic too much, but the abuse of "can't park there mate" was rather annoying.

DME relay was certainly a well known issue in 944 / 964 / etc ... I had a similar issue in one of my cars and replacing the relay was the magic solution ... but I've not read of it with 986 etc ...

Jayho said: I did think fuelling issue for a bit. But would that have manifested itself on hot days only? Or maybe the hot day was just a coincidence? Mine did the same thing four or five times, every time conking out five minutes after getting off the motorway! It's been fine ever since I changed the relay, and I found one of the pins was quite loose on the old one, so I guess some solder had given up and it was getting hot due to poor contact and then giving up. I guess a hot day would mean a component could get hot a little quicker, or could just be a coincidence.

Could be the crankshaft position sensor. Fine when engine cold, when hot car will cut-out and fail to start until cooled down

paul chocks said: Could be the crankshaft position sensor. Fine when engine cold, when hot car will cut-out and fail to start until cooled down That would be my guess too. My Son's early 986S had this issue soon after a friend bought it. The new owner took it to a well regarded local garage who couldn't find any fault codes on their non-Porsche specific diagnostic tester but my Durametric cable diagnosed it straight away. I replaced the CPS for him, which was pretty straightforward and not expensive.

Impossible to tell without the car being diagnosed properly. Worth having a look at Torque Boxsters UK face book group as it’s extremely helpful. Where are you based OP?

TROOPER88 said: Impossible to tell without the car being diagnosed properly. Worth having a look at Torque Boxsters UK face book group as it’s extremely helpful. Where are you based OP? That's the issue, as the problem only manifested for a short period of time and then started first time the next day it's quite difficult to pin point what's wrong. Part of a few Boxster groups and having a search there it seems to point to similar responses as here. Based North East of Scotland. I'll see what my mechanic says and recommends.

All sorted. Got a call from the garage saying the car is ready and that it was the CPS and all replaced now.