[Roboman]

Yep, I think you should put your old DME/relay back in once you have a known good item ...... in this case your whole car .... it could well have been a dirty connector giving a false low voltage or whatever and your old DME/relay might be perfectly okay.

 

Good luck with it all 

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[ds968]

99.9% confident it was the DME relay all along ..   I put  the car through all the motions at which point it previously  stumbled and hesitated,  for about an hour + drive , with three brief stops at some stores,  and it ran perfectly !    I’m embarrassed that after 40 years of driving 944s and 968s, that wasn’t the first thing I thought about .  It should always be ! 

However , on the flip side, I would have never discovered that I had ( at least one ) crappy cables ,  nor that one of the spark plug wells is full of oil,  until and if that would eventually have left me stranded somewhere .   So I’ll take that as a silver lining .   

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[vliegwielolaf1234]

oh well i have  been there , many times , you did it , happy days 

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[ds968]

So now .. the cold starts are still very rough until the car warms up for about 2 + minutes.    I presume this may be due to the one spark plug well oil  ?   Seems there is no problem driving the car once it’s warmed up.  Just asking if I should take a chance driving it to the mechanic shop,  or just have it towed there .

 

Also, I checked Pelican Parts , and Paragon online catalogs for the plugs 0-rings and the valve comet gasket , and can’t find those items.    I can try Sunset Porsche I suppose, but the prices from any dealers are typically 100 % more that these other sources ..

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[Cloud9...68]

Jason from Paragon was my go-to parts supplier while I owned my 968 - I would try giving him a call.  He was always super helpful, and I'm sure if the part is available, even if it isn't showing up in Paragon's online catalog, he can find it.  Their shipping was always very quick, and their prices were always very reasonable.  

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[ds968]

Thanks, will call Jason.   

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[ds968]

So now the symptoms have gotten worse, it stalls out on cold starts the majority of the time .   It takes three or four restarts before it stabilizes and runs ok,  but it continues to have issues even on moderate acceleration now .   I’ll probably have it towed to the shop on Monday , I’ rather not take chances on the road ..after all, that’s why I’m paying AAA every year ..   I wonder if these symptoms maybe point to a possible vacuum leak ..??   I’ll ask the shop to do a smoke test .   

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[ds968]

This morning’s start caused a stall right away,  and on the  secomd start the idle surged up to about 1400 rpm, stayed there for about 5-6 seconds, dropped down and then the needle started “ hunting “.   The surging is supposedly a classic symptom of a vacuum leak ( from what I read ), so I’ve done a visual check but can’t see any disconnected or cracked hoses ( from the top anyway ) .  The shop will have better diagnostic equipment so fingers crossed that’s what it is, becuase typically that should be an inexpensive fix.    Bummer I have to tow it, a couple of weeks ago I could have just driven it there ..with a few hiccups along the way but it woukd have made it .   

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[Cloud9...68]

Waylander pointed out when I had an idle stability problem with my 968 that the idle stabilization valve contains an o-ring which of course over time can shrink, creating an internal leak.  Replacing this o-ring is not easy (plus just getting the ISV out is a bit of a pain, but it was much easier on my car because I removed my AC and put the alternator in the AC's spot, which freed up a lot of space at the top of the engine) - it took a lot of prying resulting in some colorful language, and it took me a solid hour which felt like ten, but I finally pried the ISV apart and replaced the o-ring.  This significantly improved my car's idle.  Because it is so difficult to replace, I don't think it's considered a common replacement item, but you might want to run it by your mechanic when you take the car to him.

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[ds968]

A couple of valve cover bolts are already “frozen“ in place ( not surprisingly ) so they’ll likely break on removal . The shop ordered an entire new set of bolts , for safe measure .  That makes sense.   It’ll take a few days to get here , apparently the Porsche Atlanta dealer from which they ordered them , does not have any other express shipping options , just regular ground . Ugh . 

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[unknown4u]

If it stalls right away, and I red that you have already changed the dme. I should try a simple trick when the car is cold. Jumper the pins of the dme, this because you will direct feed the icv with 12 volt and also the fuelpump. The dme does those two things. Measure also if the icv will get a 12 volt at the icv. Disconnect the connector and measure it.



It could be something as a broken cable. That is an easy repair. Do not change parts if you don't know if its broke.



Measure my friend, it wil bring you a step further in the diagnose.

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[ds968]

Picked up the car today , dove it home for about twenty minutes , both highway and surface streets and put it through all kinds of acceleration in every gear , and it ran perfectly !  It  also idles at stops / lights  without any deviation .    One more test tomorrow when I start the car on a cold ( well relatively cold for California..) morning and see if it stalls like it did several  times before , but the shop manager said “ don’t throw parts at it as a trial and error troubleshooting m.o ,  let’s first see if this solves the problem “. That had to be done no matter what ( valve cover and plugs gaskets to eliminate the oil leak in the plugs wells ) , but I guess there is a possibility that m by itself it may have been the cause of all the symptoms ?!   We’ll see.. 

p.s. their computer diagnostics did not show any fault codes , before the repair,  or after .

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[ds968]

Starting perfectly on cold mornings also, so it seems the oil puddle in the plugs wells was the only culprit for all symptoms .


But I’m glad I changed the wires and distributor,  at least I can eliminate those as a possibility next time some whacky things happens .

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