#$%# car won't start! Any ideas?

motion · 07-23-2002, 08:15 AM

Excuse me for being a total mechanical idiot... that's just me.

A week ago I was driving at about 60mph and the '84 just shut off... no sputtering, nothing, just died. I pulled over and tried to start it but nothing. I waited a couple of minutes and it fired right up.

Since then, its been a little difficult to start on a couple of occasions, requiring 5 or 10 seconds of starter action before firing up, which is abnormal. Over the weekend I washed the car in the driveway, then drove it into the garage. Now, I can't get it to start at all. I checked all the connections within eyesight in the engine compartment, unplugging, blowing and reconnecting, but no go.

Fuel filter possibly? Any known electrical gremlins that might cause this? Thanks from the bottom of my wallet for any ideas!

Superman · 07-23-2002, 08:40 AM

IMHO, the first thing to do is pull a spark plug connector, slip a spare spark plug in it, and ground it against the engine. Have someone run the starter and see if there is a fat, snappy bright blue spark jumping across the gap. If you're holding it with gloves and insulated pliers, then lift it away from the engine and see how far it can jump. It should jump an inch or more. If this happens, your problem is fuel. If it doesn't, your problem is ignition.

Oh, and you're going to get some advice about stuff like DME relays. Probably good advice.

Dan Owens · 07-23-2002, 08:41 AM

Based on what you wrote it's kind of wide open so far. You'll need to do some checking for status on things. I'm going to shoot in the dark but I bet you'll get many other opinions. Most probably better than mine. First I'd check my ground straps and ground wires. Strap on trannie to body under car. Ground wires connected to engine on intake manifold, top left above distributor (look at this one first) and also a set to inside left of engine compartment behind the coil. Then I'd start by zeroing in on the area that's causing the problem if that doesn't reveal anything. Check to see if you have spark to the spark plugs, then check to see if you're getting fuel. There's also the DME relay and the fuel pump relay.

Anybody else want to jump in here?

Dan O

BER · BER's Garage

Richard,

Sounds like your DME Relay could be failing. Try swapping your relay with one you know is good and see if your problems disappear.

Bruce

jam · 07-23-2002, 09:15 AM

I agree with Dan, your explanation is missing a few details which would help solve the issue....In any case, here's a little story I'd like to share.....

A couple of weeks ago I went to turn on my '79 911SC, and it wouldn't start. The starter would crank, but that's it...the car wouldn't start up. I immediately thought it was fuel, since the starter was cranking, but I wasn't going anywhere.

I decided to check for fuel by disconnecting where the fuel exits the fuel filter. Once I cranked the car, fuel immediately gushed out. I figured the test I had just performed cancelled the possibility of a problem with the fuel pump and filter. At this point I started to doubt fuel as my problem.

I therefore checked for spark. I did what Superman explained and noticed that I did have a blue spark jumping from plug to ground.

At this point, since both fuel and spark had passsed the test, I was confused and handed the car over to the shop for a more detailed investigation.

The next day, I found out that my problem was a combination of Coil, and a so called ??? Unit (square metal box located between the rear fuses and fuel filter....some of you techies may know the name

) I had both the coil and the Unit replaced, and am now running stronger than ever!!!

Anyway, I know the 911 in question is a few years newer than mine, so not sure if my $0.02 will help, but thought I'd share just in case.

jam

jabb · 07-23-2002, 11:02 AM

Something to look at While the car is cranking over are the lights on the dash (alternator/OilPressure) on or off.....
Sometimes the Oil light will be out because the engine has built up oil pressure but the Alternator light should be on

If they are off it could be a bad ignition switch

88911coupe · 07-23-2002, 12:34 PM

I just went through a similar situation and thanks to this board figured out it was my DME computer's solders that had developed hairline cracks. They are hard to see but pretty obvious if you look VERY closely. My car would always turn over fine but only start/run sporadically. I redid the solders and now it's perfect.
Saved me $1600 but I still got hosed for $320 in "diagnostic fees" by Park Place Porsche.
Good Luck

motion · 07-23-2002, 12:42 PM

Great advice all... thanks. I've located a DME relay and will swap that tonight. If that's not it, at least I have a spare. Plug check after that... I can do that myself. If not, then its the flatbed I'm afraid.

motion · 07-24-2002, 08:33 PM

WOOWHOOOO!!!!!

$46 = (1) DME relay from Hergesheimer's + 2 minutes to install = 1 fired up Carrera!

Man, I love you guys!