Porsche Enthusiasts Club Forum

Hi,
Is it normal for a 944, s2 in particular to have a warm start problem?. The car
always starts. Starts perfectly when cold but if the engine is warm it is
sometimes quite a job to start. For example popping in to buy a newspaper
then coming out and starting the car.

I have heard this problem was quite common on older cars a few years back.
I put in a new dme when I brought the car. Is this problem typical with the
s2? and if so is there a way to try and cure this?. I have mentioned of a
"cold start valve".

thanx Warren

It may be the DME relay, it's sometimes caused by a failing DME Relay and quite a cheap and easy fix, I'm fairly sure it was something that happened to my car a couple of years ago before I replaced it. I can't rmember exactly and I expect someone will be along to either confirm or give a better answer

Firstly the warm start problem is the 924 with mechanical injection not the later electronical jobbies. DME relay is a possibility & a cheap quick fix. Other possibles are coil or possible at high mileage a leaking injector. When it eventually starts does it do so in a cloud of black smoke & lumpy running? If it does then it could be a weepy injector. The next time it does it whip a plug lead off & plug a spare plug in & gets someone to turn it whilst see if the plug sparks, if it does then get an injector service done, if not then go for the coil. Do DME first though, as you should carry a spare.

Hi Jim,
Thanks I appreciate the info. I have changed to a new DME. That did not solve the problem.
When the car is cold, it cranks and starts with no problem.
When the car is warm, it cranks .... takes a time to "catch" and feels for a few seconds
that it is not running on all cylinders then when I press the gas pedal it comes to life. But
sometimes it just dies and I have to start again with the key.

There is no cloud of black smoke whatsoever. But when the car is very warm the start is always lumpy. But once started the car drives fine. The car is from 1990 and has done
184,000 km. But the last owner did a lot of major work on the car. Last year new water
pump, new cam.

I have read on other sites of a similar problem with 944's. They mention that the "cold start valve" could be the culprit?. Have you heard of this?.

Just last week I have used STP injector cleaner .... mixed in with the petrol.

I will try your advise with the plugs. Do you know if it is very expensive to get an
injector service done? is it better to go to Porsche for this?

Thanks for your help, much appreciated / Warren

Hi.

Where about is this DME relay located? Also, does anyone have a part number and/or a good place to get one. It's for '89 S2. I think that perhaps I should carry one with me just in case.

Regards,

Ben

I got mine form my local Porsche Centre for about £19 I think.

Jim, you said "Firstly the warm start problem is the 924 with mechanical injection....." My 924 has this problem. As I get loads of admiring looks from mere mortals when I'm in Tesco's car park it's blood ee embarrasing when it cranks over for what seems like hours until it starts! Is there a thread on here you can point me to which may help? Many thanks!
Gary

DME relay is £20 +vat at OPC, it is in the fuse/relay box under the bonnet

In late cars, early ones it's underneath the glovebox.

OK, an injector agent in a bottle will not service or clear injectors on the S2/968 Motor. You will need to go to a specialist who can perform an 'Ultrasonic' injector service. Do a ring around and ask some local indies. This problem could be one of a number of things, Injectors, Plugs, MAF(this can get a heap of crud built up on it and it can do funny things).

An indie will (should) be able to test and diagnose this issue and advise the relevant repair and costs.