Porschenut_Lee

I searched previous threads but found nothing. Maybe you guys can help.

Car - 1984 911 bone stock 86,000 miles

Last night I replaced my Distributor Cap, my rotor button, and my spark plugs. I did remove the AC compressor from the car before doing plugs considering the AC didn't work and I wouldn't use it here in Maine anyways. Upon completion of the repairs I hopped in the car, anxious to take the car for a spin and the car wouldn't fire. It turned over fine but the engine wouldn't start. My first thought was that I mixed up my wires on the cap, but after checking and rechecking 10 times I concluded that this was not the case. I reinstalled the old rotor button and distributor cap with no luck as well. This tells me that the new rotor button and dist. cap shouldn't be the problem. I can't imagine I screwed anything up when I changed the plugs. I doubled checked all of my plugs and plugs wires for correct seating. I can't imagine that removing my AC compressor did anything to disturb the ignition. I did check for spark from the coil to the distributor and after playing with the wire a little I did get spark.

The only thing right now that comes to mind is a complete new set of plugs. However it seems that even if one or two of my plugs were bad the engine would still fire, but run rough. Perhaps it is just the wire from the coil that is bad. I would hate to spend $150 on plugs to find that they were not the problem. Any thoughts? Any help would be greatly appreciated.

Thanks,

Lee

Porschenut_Lee

By the way, the distributor cap is installed correctly with plug wire #1 lined up with the TDC notch on the distributor. I don't know if it is possible to put the cap on wrong (turned 180 degrees). Either way I thought I would mention this also.

Thanks,

Lee

DGaunt

If it doesn't fire at all, then the probelem is something that affects all cylinders. Thinking coil wire maybe. Do you have a spark there?

I'm still wondering if you have the wires shifted one spot either way. Suggest to double check that you put the engine at TDC and check the way the rotor is pointing.

Last, IRRC, that notch indicates where to insert the distributor into the engine, and the rotor will rotate as the dist. is slid down onto the gear.

The more I think of it, the more I am convinced this is your problem.

Good luck.

r911

It has to be something simple - something you will kick yourself for later (voice of experience talking - we've all been there).

Be sure to check any wire that you could have bumped while in there - esp. things you did not work on.

If that and the post above fails, then start looking for a spark from the coil; then work back with a voltage meter or light looking for where it originates.

DonMo

I had something similar, one of the three wires on the veritical on the left side of the engine came off. It was one of the sensors just above the O2 sensor connector.

Porschenut_Lee

I assumed that since my ignition is electronically controlled that I didn't need to set my rotor at TDC. The rotor can only go on in the sam way it came off, and cannot be turned. The manual says that no timing adjustment is required unless the distributor itself comes off.

As for notches, there is one large notch that is made to align the distributor cap, and another very fine, hard to see notch that lines up with the #1 cylinder wire to indicate TDC. Both notches are lined up as required. I must have checked the proper placement of wires at least 15 times by now. It would have been very easy to pull a small wire as stated considering the force it takes to pull the plug wires and break the spark plugs loose. I will look further into that possibility. Gets kinda frustrating when you try to make the car run better and it ends up not even starting when the job is complete. Thanks again guys for the suggestions.

Lee

SPDRacer

When you say that you had to play with the wire a little to get spark, did you replace that wire so that it would make good connection? I would check the wire that runs from the negative side of the coil to the distributor to see if that is the culprit. Good luck.

grn356

A few days ago I checked one of my spark plugs (#3) to determine brand & condition. After I replaced it my engine wouldn't start. I checked all nearby wiring to make sure I didn't knock anything loose. Then I had it flat bedded to my friendly Porsche mechanic. The problem turned out to be either a loose connection at the DME or a bad DME relay. A new DME relay was intalled and the engine now starts just fine. Probably checking the plug had nothing to do with the problem. (The replaced relay had a date of 1999).

Charlie P.
'87 911 Carrera
(60,000+ miles)

jmech

I may be stating the obvious but it may be the large black plug on the engine bulkhead behind the blower as mine is a very loose fit and can be easily dislodged.
You may be able to check the DME relay if you haven 't got a new one to try, by removing the plastic case and visually checking to see the relays switch when the ignition is turned on and when the engine is cranked. If your DME is of the solid state type the you wont be able to see this.
The other thing as already mentioned is the 3 sensor plugs on the left of the engine, mine would not start due to the CHT sensor plug being loose.

Hope you get it sorted soon!

Porschenut_Lee

Once again Rennlist to the rescue. Behind the blower on the left hand side of the engine are 3 wires plugged in mounted vertically. The bottom plug was completely off, but situated so that it looked like it was plugged in. As I began my search for loose wires I noticed this one hanging freely. And as you can guess, plugged it in and the engine fired. I guess after hours of frustration and about 20 attempts switching out the new cap and rotor with the old cap and rotor and back to new again, I learned a valuable lesson. Thank you to all that offered suggestions. This list is a great thing. It was nice to hop in the car and take it for a spin. The car runs better with no hesitation or flat spots in the rpm range. What a blast this car is.

Thanks again!

Lee
1984 Targa