3.2 Carrera No Start after Running Fine
 

Went on the NY/NJ/CT fun run yesterday and the car was starting/running fine. It had been for the most part for months. I'd had some infrequent cold start issues awhile back, but I thought I was past those.

Car cranks, seems to catch for a fraction of a second, tach jumps and then it dies immediately. Continued cranking does nothing but wear down the battery.

I'm getting a good spark at the coil wire with a tester setup. New in the last three months/2500 miles: the coil, rotor, dist. cap, sparks, fuel pump relay and DME relay. Took the cap off and did a visual inspection and nothing seemed unusual.

I jumped the fuel pump fuse to the adjacent fuse, heard the pump whirl but with no difference in the attempted start failure. I understand. perhaps incorrectly, that this overrides the DME and generally eliminates most DME issues.

Yes, there is gas in the car.

Fuel pump/fuel pressure problem? I would think I would still get something of a rough start before it died particularly with the DME override. The no start is so consistently brief and identical to each other no start that this seems less likely to me. However, this is what was happening with cold starts awhile back, although I was always able to get enough of a catch to then give the pedal some gas and get it going after a few tries.

Checked the contact point on the driver side fuel rail and it seemed clean. I did not chase it to its ground (behind the fuel filter?).

CHT sensor? Nice mild day here, but I have no idea whether that would have any bearing on a faulty sensor. Seems to me a faulty sensor is a faulty sensor no matter what the temperature.

Other?

I suppose the other possibility (probably pretty remote) is that I installed a new power seat (replacing a manual seat) the other day and grounded the circuit on the same body ground as an after market Alpine 8026 alarm which has an ignition disable feature. However, I locked and started the car a dozen times or more after the install and everything worked fine until this morning. Also, if I somehow tripped the ignition disable, I would think this would not allow the starter to even engage, which it is certainly doing.

Any thoughts greatly appreciated?

Jim

It'd be helpful to know what your fuel pressure is if ignition is ruled out.

But, electrical/ignition issues can be erratic making it difficult to pinpoint I'm sure you are aware.

It's one of those situations where you wish the car would not start at all to figure it out.

Are you getting spark to the plugs? You say you tested spark only at the coil. I found an Early S Man thread that talks of vertical slop in the distributor shaft. May not be the problem but worth a look to eliminate the distributor.

Here is a link to searches on "Carrera starts then dies"

http://forums.pelicanparts.com/search.php?searchid=7554076

Hi Jim,

I had a similar problem in my 1988 911 this summer after a 300 mile day of hard driving. It was debris from the fuel tank clogging up the prefilter screen. Had the fuel dropped from the tank and screen cleaned. It solved my problem.

Sounds like your DME relay is bad. Can you pull it out and take a look. I believe it is right under the front of the seat where the adjuster is.
Oh by the way we probably met yesterday I was driving the 914. Hell if you had a setup like the blue 2.8 RSR all you would need to do was to flip a switch everything on that car had a backup!

Cheers.

Scott

Put your hand on the DME relay. Turn key, if you can feel it click.....good, no click....bad or just not getting power.

Jim

I have a Spare DME relay if you want to give it a try. Looking for an excuse to go out for a ride.

Paul

Paul- Thanks for the kind offer but I just replaced the DME relay two months ago so it's likely not the problem. I'll try the click/no click test Joe Bob mentioned.

I'm thinking Scott may have a good point with the fuel filter - put 240 miles on yesterday and I don't know the vintage of the filter. When I jump the fuel pump fuse, it's certainly pushing a lot of gas - I can smell it from the front of the car, but it dies so quickly, I'm thinking it's probably a fuel issue. Fortunately, I have a new filter which I'll change out in the morning and give it another try. Didn't know there was a pre-filter screen but I'll try to hunt that down as well.

Thanks for the pointers. Love this car, but she can be trying at times.

Jim