1997 993 Won't Start

[gmartin]

The car has been sitting on trickle charge for about a month. I was driving it a few times a week to and from work before this sitting period.
It cranks just fine and sounds healthy. Just won't start. It's low on gas; about 1/8 tank left. Any suggestions to get it to fire up?
Thanks

[Marine Blue]

First thing I would check is the DME relay, they often cause a no start and or will randomly shut the engine down.

[gmartin]

Hi Marine Blue - thanks for suggestion of DME relay. I’ll let you know if it’s the culprit.

[Kein_Ersatz]

+1 DME... If failed, replace with digital version for hopefully longer life. Always carry a spare, cheap tow avoidance insurance.

[gmartin]

Thanks Kein - could you help with Brand and Part Number on the digital version of the DME?

[Marine Blue]

Originally Posted by gmartin

Thanks Kein - could you help with Brand and Part Number on the digital version of the DME?

Here’s a link to the website, you’ll need to decide which version you want: https://www.ftech9.com/new-products?category=SSR+%28Solid-State+Relays%29

I just picked one up for my 964 last week but haven’t had a chance to install it yet. I went with the standard non priming to stay with how the car was originally designed. I’m keeping my original as a backup in the car.

[gmartin]

Thanks again Marine Blue! The Diagnostics version is slick. Will most likely be ordering this one. Based on part numbers, non-primed seems correct for my car as well.

[Kein_Ersatz]

Marine Blue got to it first. FTech9... No affiliation, just a happy customer.

Me and all my 993 pals run FTech9s and many use the old analog as their spare. Not aware of any Ftech9 failures yet, been around for a 3+ years.

Also Jay's IMMO block is also a nice mode to lose the key fob 30-sec re lock "feature".

[gmartin]

Thanks Kein! Good to hear you agree that FTech9 is a solid option for the DME. And thanks for the time on the IMMO block - the relock feature is definitely annoying.
On a no start related note, I emailed a Porsche racing and street shop here locally, and they said it may be the crank sensor - have you heard of this sensor failure?

[Kein_Ersatz]

Yes that can fail out of the blue (old plastic), but harder to get to to replace and to remove/replace.

Went to pick up my 993 a few years back from a shop service, they drove it to the detail stall while I was there to give it a quick wash, then when they went to pull it out and give to me, it would not start. DME first thought, but a swap didn't fix, then on to crank sensor, fixed it.

[gmartin]

Thanks Kein - yeah, hoping DME not Crank Sensor - much more difficult to swap!! Thanks again for the help.

[gmartin]

Well, it's not the DME. So, on to the 10X more difficult crank sensor. Does anyone have technical instructions for this fix? Could not find anything on this site. Thanks

[Kein_Ersatz]

https://rennlist.com/forums/993-forum/784293-adjusting-speed-reference-sensor.html

Discusses how to remove / and adjust.

Bentley Manual has how to remove / install, but doesn't reference any adjustment.

[bazar01]

Stop the parts cannon.

If you diy, invest on a pico scope.
View video at 6:00 to test speed and ref sensors
https://youtu.be/L1jJpLzshP8

[gmartin]

Thanks Kein and bazar01. I appreciate your feedback - it really helps.
Bazar01 - I think you are absolutely right - If I want to be a DIYer, I should have the proper tools - thanks for the link showing the Pico scope. Franny is a genius home mechanic!

[gmartin]

Well, after me trying to figure it out and failing, I had a local shop diagnose and its a bad fuel pump. Not a terrible fix as far as cost, so should be back on the road soon! Thanks for everyone's input and help. I also purchased a pump-primed DME from Focus 9 Technology.

[mysocal911]

Originally Posted by gmartin

Well, after me trying to figure it out and failing, I had a local shop diagnose and its a bad fuel pump. Not a terrible fix as far as cost, so should be back on the road soon! Thanks for everyone's input and help. I also purchased a pump-primed DME from Focus 9 Technology.

Next time do the MOST basic tests (Remember, an engine needs both spark & fuel);

1. Pull a coil wire and check for a spark.
2. Spray carb cleaner (fuel) into the air cleaner.

[james_david]

Okay

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