z851@yahoo.com

I've been having troubles off and on for about the past month (about 6 times). The car usually starts right away. If it doesn't, I go under the hood and wiggle the coil wire and some of the vacuum lines. After 2 or 3 times it will start. I replaced all of the vacuum lines over the weekend. After replacement the car started and idled fine. I didn't drive it this morning when it did not start. I will pull a spark plug and check spark and check for fuel. Any thoughts?

PorscheDoc

When you say won't start, does it turn over and just won't fire or what? If while turning it over, does the tach move at all? If not, then it is your reference sensor connectors.

z851@yahoo.com

Thanks for the response. Yes, it does turn over it just won't fire.

I'll check the tach when I get home.

z851@yahoo.com

Well when I got home it started right up. Do these cars have a switch on the clutch pedal?

PorscheDoc

i don't believe so, i can start my car without pushing in the clutch. More than likely it is your reference sensors, that sounds classic, and wiggling around lines in the engine compartment, more than likely moves those as well. Just make not of if the tach moves or not next time it won't start.

speedracer18

I know what it is, mine had every possible problem but is almost restored now. change the relay that controls fuel control. I think its the fuel dist./ or pump relay. but its a fuel something relay. Their like 50 bucks new.

z851@yahoo.com

Since the reference sensor is free....I'll start there. I had the some problem on my F-150 about 2 years ago. Do I just need to tighten it a little bit?

If that doesn't work, I'll try the relay. I didn't try it this morning. I don't want this thing to let me sit anywhere....so I drove the Boxster this morning!

Thanks Crew!!!!!

PorscheDoc

DME relay is what it is, 19.99 most places.

Andriko

I'll say it's the DME Relay that controls the fual pump and engine management system, over years of use the solder joints dry up and when there hot the don't work until they cool down. It'll say DME on the relay say can't miss it. Theres a big write up on these in 911 and Porsche World magazine.

z851@yahoo.com

OK....last night on 2 different occasions it started right up. This morning nothing, and the tach was not moving when I was cranking the motor. Are we back to the flywheel sensor?

Kurt R

Can you hear the fuel pump run? Next time it doesn't start open the fuse box and tap on the DME relay, or make a jumper wire to bypass the relay.

Check out these links from Clark's Garage:
DME Relay testing
Speed and Reference senders

z851@yahoo.com

Clark's Garage....now that is a great web site!!!!

Thanks!!!!

PorscheDoc

If the tach is not moving when you crank it, your reference sensor is bad, or the connection is bad. Mine was bad on the wiring harness side, and i couldn't see it until it stripped back some of the insulation...i had to broken wires of the 3.

z851@yahoo.com

Hi Crew,

I just wanted to post what I did find. It was the connection at the plug of the flywheel sensor. I wanted the thank you all for your help. So far so good.

chitown928s4

where is the flywheel sensor....is that the same as the crank sensor...the PO said to check that but i dunno where it is...im just now experiencing problems where it starts fires up them immediately shuts off...on another ocassions it starts then i give it gas abd bogs then shuts off