jo-hans

Hi guys, hopefully someone can help me here.
I recently did some work to my 993 - replaced the sparkplugs and had the distributor rebuilt among things.
Starting the car seemed just fine at after this work but now every time I do a cold start the engine cranks and starts but sputters and dies - on the second crank the engine starts fine although a little rough at times.
I did a search - could this really be related to a faulty Thermal Temperature Sensor? Any other possibilities?

Thanks,

Garth S

There is always the (classic) possibility of of the DME relay beginning to fail ...

jo-hans

Garth - I have two spare DME relays and did the swap with no improvement.

AOW162435

How about that Hall sensor thingamajig on the primary distributor?


Andreas

Streetfighter

How many miles do you have? Are there any check engine lights on?

Tweetie

Hans,

I also had the same problem, it appeared to go away after I changed the DME relay but has now reappeared. ISV was cleaned and made no difference what so ever.
Can't wait to have this mystery solved.

Ian

98 C2S

jo-hans

I don't know and have not found anything about the Hall sensor on the distributor.
I never had my CE come on (yet - knock on wood) Just hit the 200,000 km mark.
I cleaned the ISV last year. (Ian have we met yet?)
I have a new starter.
Okay so I dropped an email to Dr. J (Mike J.) Hopefully he's got some pointers.
Maybe it is just as simple as a loose plug onto one of them sensors.

jo-hans

Oops double post - must have hit the button twice

Streetfighter

I am thinking it maybe your fuel pump? Or a clogged fuel filter?

jaholmes

I am having a similar problem, but it's when the engine is warm. I have changed everything that you have, plugs, wires, distributor belt. Not sure what the HAL thing is but...ISV too.

I just checked my DME and it's the old 944 part number so I am getting a 993 DME.

I have changed the fuel filter, but it may be the fuel pump. I will go with the DME first.

boulderbobo

+1 sounds like a fuel issue to me....

Tweetie

Hans,

No, we haven't met yet.
I have a brand new fuel pump so I don't think thats the problem.
Fuel pressure has been checked and is fine.

98C2s

Ian

jo-hans

Didn't think so Ian - I have a lousy memory at the best of times (hey - check the local PCA site for upcoming events)
It is good to know you ruled out the fuel pump.

So I got a response from Mike J. and this is what he said:

OK, its either fuel or ignition.
Could be fuel pump having a hard time getting the pressure up. When it starts, does it sound fuel starved?
On a 993, I am not sure what a Thermal Temp Sensor would do, other than provide feedback to the computer that the engine runs a bit rich while cold. Does it sound like the car is getting too much fuel? You can leave the car off overnight, try the start, and pull a plug to see how much gas is on it. If its really wet or gassy, then the fuel injection is fine and its ignition ; if dry then you are not getting enough fuel.
I can’t see how ignition can play here, there is nothing dependant on the engine temperature that I can think of.

It indeed sounds like it is fuel starved and not too much fuel.
One thing to note is that on the second crank I get a pop (backfire) and the car starts to run fine.
Before starting today I will check for loose connectors. Then try the first crank and pull a plug.

Thanks for the feedback.

993inNC

Try changing your fuel filter, also may want to look into having the injectors cleaned. The pop sounds like maybe a fuel dump in one cylinder or more (sticking injector?). You could also do a fuel pressure check in line and after the filter, see if the pressure is within specs. Could also be a pressure regulation issue (not up high enough on the first crank) but if you have fuel dump, would explain the first start and sputter to die (would be my guess over anything else)

timothymoffat

Maybe we spilt beer on something during one of our winter "meetings."