V

I had trouble starting the car today and just wanted to run this by you RLers. I drove the car for about 20 miles, turned off the car, went out to open the garage door, went back to the car and it wouldn't start. Cranked but no fire. Tried to lock/unlock and cranked again but no fire. After multiple attempts the battery went weak and no crank. So I tried jump starting it with cables from another car and it fired right up. Just garaged the car and put it on a battery tender. I suspect the battery is getting weak and that that is the culprit. Although the CTEK charger showed "full battery" when I plugged it in after the jump start, hmm. Or could it be a faulty DME? But if it is the DME then the car wouldn't start again like it did, would it? Forgot to take my spare DME out of the glove box when I sold my old car. Perhaps time to order a new one?

The car had been sitting for 3-4 days and the battery felt a bit tired when I started it before the drive. But wouldn't the battery take charge during the drive? It feels odd that it didn't start after the drive. I've had this happen once or twice with my former 993TT, but then often I just waited a bit and then it fired up again, probably because it was running too rich for some reason. Could just be a one time thing but strange.

Appreciate any feedback

Texas993

Replace the DME - they can act strangely. Then get the battery checked out by a shop.

ronnie993tt

+1. I'm having batteries go at least 7 years now but carry 2 spare DME's....original for a Porsche buddy in need and a fresh one pour moi.

dombeau

Just wondering. You carry a spare DME relay? Like this one: http://www.suncoastparts.com/product...93TT_intaccess

V

Yup seems like a no brainer to keep a spare in the car. I'll order a new DME right away. I read somewhere that if you remove the DME you can't use it as a spare, I guess that only holds true if it breaks?

I'm just puzzled because it seems that either the DME is working or it isn't. So I'm thinking it could've been just a one time thing where the engine was running rich when turned off and therefore it wouldn't start shortly after. I've only had it happen once before but that was a few years back. If the battery is good, how many start attempts would it manage before giving up (no crank)? I could do maybe 6 attempts before the battery weakened and then no crank. Normal?

Basal Skull

do our cars have a check valve that maintains fuel pressure when shut down? or perhaps a fuel pressure regulator problem.

ca993twin

Without any hard evidence to back me up, I'll offer this:
The DME fails due to bad solder joints. This can create an intermittent issue. Always carry a good spare.
A good battery should give you more than 6 attempts at starting before quitting... unless each attempt lasts way too long. I would hazard a guess more like 30 attempts before you would notice a slow-down in cranking speed. Just a guess.

V

I ordered a new DME from my local dealer, I will have it tomorrow. The battery does seem on the weak side, we'll see how it does now when fully charged. I will at least try it as is before I replace the DME. Will carry it with me though, so if it doesn't start then I will replace DME and try again before the battery dies .

OverBoosted28

Keep the battery on a smart tender at all times when the car sits for more than a few days. Since your car is modified you may have the same situation I have. If the car is shut down without being at a smooth idle (any throttle input at all) the cylinders will be flooded. Keep pedal to floor while cranking and the gas gets pumped out and it will/should start. The first time i experienced this I was at a loss wondering why it wouldn't start. The upgraded fuel system is overkill when the demand isn't there. Just a thought, if you run into it again and it's not the DME relay.

Texas993

RUF doesn't upgrade the fuel pump on the TurboR. So V should not experience what you describe. I have never had to do any of what you state above. But I never remember having a rough idle, ever.

V

This was what I was thinking at first. It sounds plausible. I can't remember if I had throttle or not when I turned it off but it makes perfect sense what you are saying. I just thought pedal to the floor when starting would make it worse but you learn something new every day . This happened to me in the past but only one or two times and it fired up after the second try. Anyways, loaded battery now, new DME (to keep in glovebox) and knowing this I will hopefully not have any problems in the future. .

ronnie993tt

Pretty much but I got 2 for $54 from Pelican 3 years ago. $103 each at the stealers up here.

PelicanParts.com

V- glad you're back on the road!

V

Thanks .

I have kept the car on a battery tender now for two weeks. Just went to the garage and tried starting the car. It fired right up but it felt like the battery was a little weak. I could be wrong though. The CTEK charger shows the icon with the 100% battery. I also detected a slight fuel smell in the front trunk area. Hmm. New spare DME from OPC is now in the glove box but I'm thinking the battery is getting old. I didn't start it more than once today as I need the car to start tomorrow . I'll keep my fingers crossed.

V

Just thought I'd post the conclusion just for the archives. The battery is weak, that was the culprit. It's weak to the point that if you jump start it and drive the car for 5 mins, it wont start again. So I need a new battery asap. Problem is I won't be able to source one tomorrow so I'll have to take my chances with a portable starter to (hopefully) start the car and drive it one hour to my garage. I'll just have to make sure I don't stall the car once it's started, then I'm in trouble. If the car starts, I should be fine right? Since the car really doesn't need the battery at all once it's fired up.

Have a great weekend!