sh944, could you explain to the uninitiated what your last post meant?

 

Sure! In the past, there have been a number of folks that were posting non porsche related, or worse yet, BS posts about supposedly porsche related stuff here. Every now and again, one of those posts surfaces, and I am doing my best to keep those posts "buried" (away from the top of the trhead list) so that the troublemakers will stay away and we can concentrate on real porsche related issues, such as yours. "Bump", by the way, is an acronym for "bring up my post". I was trying to move this post up to the top, as its one of the good ones.

I want this forum to be worthy of the name "Porsche", at least until the cease and desist order shows up for trademark infringement... at which time the webmasters will have to think about changing the name (hint hint hint). In the meantime, anyone that thinks they can get away with showing up and causing trouble here or post BS had better think twice, I won't tolerate it.

Foz, keep your posts coming, you are one of the good guys!

Regards,

 

Now I understand.Thanks. With the amount of info I have gathered, I am going to give it a try in the next couple of weeks. Now assuming I get it going ( which I think I am more than capable of doing!) the car doesn't idle well from cold, it is rough running and stalls. Once it is warm, it is fine, starts fine, runs fine. Could this be related to the DME temperature sensor, or the idle control valve. Hope this also keeps this post - BUMP. Grateful for the response.

 

Bump (again... *sigh*) to bury another thread that has less value than this one...

 

This seems the closest thing to the my current 1988 944S problem. After a 40 minute drive in the dark this morning the car died in the parking lot at work - it turns over fine (unlike the last time when I lunched an engine[:@] in the same aprking lot three years ago) but makes no attempt to start. I have ~23,000 miles on the timing belt, tensioner, water pump, etc. in the current 1987 944S engine in the car. It has gas, it has no blown fuses and I will check the belt (but having heard the collosion of piston and valve in a 944S engine I know this did not happen this time).

It is acting like no fuel or spark. Suspect DME is there a cheap and fast way to check it? Am I overlooking the obvious somewhere?

Is there a silver bullet here for me at all?

thanks,

jeff

 

OK - just to check what is going on I pulled the inspection plug for the belt - guess what - it does not move[]......

Very frustrated at the moment since the entire system is at 23,000 miles since I put all new components in. I even had the belt tension checked per the manual after the new install.

I love driving the car (not as much as my ZO6...) - but I sure am getting tired of these engine woes[:'(].....

Good thing I am getting good at pulling the engine.....

 

1st, using a multimeter, measure the resistance between terminals 30 & 87b, then between terminals 30 & 87. In both cases the reading should be open circuit (no connection).

Next connect a 12-volt supply to terminals 85b & 87. This should activate the relay & close the connection between terminals 30 & 87b. Check that there's no resistance between them (or certainly no more than 0.2 ohm).

Now connect your power supply to terminals 85 (- Negative) and 86 (+ positive) & check that there is no resistance between terminals 30 & 87.

If you see a higher resistance between the terminals when you make these two powered tests, you can assume that the relay is faulty.

The problem will either be poor contacts or a failing soldered joint. If it's poor contacts you can try cleaning them, but this is a short term fix. If it's a failing joint, you could try re-soldering it.

Remove the black plastic top from the relay and any dodgy soldering should be obvious. Look for a tiny gap between the blob of solder and the wire that may be poking through it and for flux oozing out. If you are handy with a soldering iron you should be able to make the joint sound again.

 

That is for the DME relay only. There really isn't a way to test the DME, you can pull it out and check for cold solder joints and repair them. One way to check, is to jump the dme relay, then pull the rail and see if the injectors are firing when you are cranking. If they are, then the DME is probably good. If not, then you have dme problems.

 

Actually, thats not quite right. There are several ways to check a DME. On a 944S, you can do the CEL test by turning the ignition key and counting the flashes, assuming your DME hasn't suffered a critical failure. If the DME has suffered a critical failure, if you have access to a Bosch Hammer or a JDS Spanner, you can determine DME fault. Unfortunately, those tools are a bit beyond your "typical" enthusiast (um, I guess that makes me a bit "atypical", eh? lol) and given the cost, its easier and cheaper usually to look for DME cold solder joints, which is the most common DME fault.

Bummer on eating a belt, dude! Its never a fun proposition, especially with the 16V head. Lets us know if we can be of any help.

Regards,

 

Looking at options at the moment - I have two broken 2.5 liter 16V engines. Not real keen to put another one in of the same type.....thinking V8 at the moment.