77 911S 2.7 Cranks - won't start

[Orange911S]

I've got a stock '77 911S with the original 2.7 motor (33,600 miles). It came out of storage last November at 31,200 miles and had a good going over including new plugs.

This morning it was running fine on the way to work which is about five miles. Leaving the last stop light before I enter the parking garage I usually just keep it in first. I did that this morning and while running about 3500 - 3700 RPMs I felt a "miss". This was not a backfire, but the RPMs dropped about 1000 RPMs for a second or two and came right back.

I was a little concerned, but it ran fine the rest of the way and I drove into the parking garage and parked.

After work I came out and when I went to start it I turned the key and it didn't turn over. It usually takes only a quick (1 - 3 seconds) turn of the key to get it going. Sometimes two tries, but starting has never been a problem. I tried a few more times and plenty of juice to the starter but it didn't catch. I usually don't give it any gas, but after a few tries, I gave the gas pedal a little push, but still nothing.

Where I parked was on a bit of a ramp so I tried to compression start it, but I didn't get enough speed for a good try.

I called AAA, love those guys, and the driver pushed me again, but not enough speed to give it a really good chance of starting.

So now it is sitting comfortably in the garage, but I am a bit stumped on where to focus for fixing this. My suspicion, and the tow truck driver's, is that we are missing spark, not fuel.

Could the "miss" be tied to something with the starting or is it just an abnormality?

Where should I start sleuthing to figure this one out? I searched the forums while waiting for the tow, but did not see anything that seemed directly related to this situation.

Any help or direction is appreciated.

Thanks

[kodioneill]

failed set of points or cd box.

[pors1968]

Ignition swicth make sure you have power at cd box.

[T77911S]

what i love about this year is there is not a lot that can keep it from runnig.

check for spark first. points are not a big failure item. if no spark you can remove the dist cap and rotor and make sure the points completely open and completely close. gap is not critical to make it run. you can also alternately ground and remove ground to the wire at the dist to fire the ignition. that wire from the dist to the CD gets brittle and can short out. outside of that swapping out the coil and the Cd is about all you can do

there is a connector on the back of the air flow meter (AFM) on the left side that you can remove. turn the key on and make sure the fuel pump runs with the key on. (just leave it off for now). with the FP on, you can reach into the air box and lift the sensor plate. there should be no play before you feel resistance. you should also hear a loud squeal when you lift it. do not lift it too long, it will flood the engine.

cold starting is aided by a cold start valve(CSV). you can "bypass" the CSV with the test above. try starting it right after lifting the sensor plate.

[Orange911S]

Thanks for the pointers. I may have time over the weekend. I am still pretty new to this and don't want to start by throwing parts at the problem or paying a mechanic's mortgage.

[74-911]

Originally Posted by Orange911S

After work I came out and when I went to start it I turned the key and it didn't turn over. It usually takes only a quick (1 - 3 seconds) turn of the key to get it going. Sometimes two tries, but starting has never been a problem. I tried a few more times and plenty of juice to the starter but it didn't catch. I usually don't give it any gas, but after a few tries, I gave the gas pedal a little push, but still nothing.

Where I parked was on a bit of a ramp so I tried to compression start it, but I didn't get enough speed for a good try.

I'm confused by your post: does the car just not start when you crank it over or does the engine not turn over when you turn the key ?? If the engine is turning over when you crank it, why try to push start it?

[MongooseGA]

I've had a few no-start issues in my '77 as well. The problems for me ended up being 1) a damaged 'green wire' from the distributor to the CDI, and 2) a brand new MSD coil gone bad.

These were at two different times, about a year apart.

If you have a spare coil, it only takes a minute to swap it in a test that theory.

Otherwise, try the CDI. Which unit is in your car?

[Orange911S]

Finally had time to take a look.
I recharged the battery and tried to start it up this morning. We could smell fuel, but there is no spark. I will be ordering the MSD ignition upgrade from our host and hopefully drop that in before next weekend.

The current CD box is a perma tune. I don't know if it was stock or a replacement part, is there any way to tell? The coil is a Bosch and my assumption is that it is original.

More as it happens.

[dipso]

Make sure your points are not closed. Sometimes the pad on the points that rub on the distributor shaft, will wear down to where the points no longer open. If that happens the car will not start.
It happened to me once.

[Orange911S]

So I spent my evening hunched over the back end of the orange beauty and things did not go that well. I read Wayne's article and thought that maybe I could knock this out in four hours. Turns out that was not the case.

I started by working on getting the old perma tune CDI out and the aluminum panel unattached. I had a few missteps here and ended up pulling the hose off to make more room to work. Then things got interesting.

The old perma tune blue box is just over half the size of the MSD 6425 so I did some head scratching and searched through this forum for photos of installations. I didn't see one that I could follow that would be easy. I had an extra component on the electrical panel that I had not seen in photos or that I recall being written about. It is a beru part, and shown in the photo. With this on the panel, making room for the MSD was looking hopeless.

I put the panel all back together and reattached the hose and decided that in the time I had left this evening I could replace the Bosch coil with the MSD unit I bought to match the new CDI. This took a little doing considering the mount was built for the slimmer Bosch and it took a little extra convincing to get the new coil in. Once in, I reattached the battery and tried to fire it up.

Same result, the starter turned fine but the engine didn't catch. I smelled a little fuel so I am still convinced it is a spark issue.

Tomorrow I will check the points and give more thought to the placement of the MSD.

Here are a couple of questions. What is the brown beru part in the picture and will I need it with the new CDI? Also will I need the tach adapter that I bought? If I do, I need to get creative on mounting that too.

Also, any creative mounting or placement ideas would be appreciated.

Oh, one more, and don't laugh.., I still can't see where the starter is. I am thinking that is the place for the 12V connection. Any pics on where this is on a 2.7?

Thanks for all of the insights so far.

[dipso]

I think that is the voltage regulator. If you get a new alternator with an internal regulator, you won't need that anymore.
The silver thing is for the rear window defroster I think. You probably don't need that either.
You should be able to get 12v power from that fuse panel in the rear that has 3 fuses on it.
1 or 2 of them are switched power. I think the middle.

Double check all this information, but I think it's right. It's been a while.
I didn't need my tach adapter.

[Orange911S]

It turns out that the Perma Tune, which was the OE CDI box was the culprit. I finally got it all out back together after many struggles to mount all of the pieces to the panel.

Hearing the engine start up once everything was back together was a huge relief. There were many trials and tribulations, especially around mounting the big MSD box and the tach adapter.

I will add details over the next few days.

[MongooseGA]

I remember that same feeling of the engine finally starting after close to 6 months of me not wanting to deal with it any longer. I did the MSD CDI and coil upgrades, only to find that the green wire was to blame.

Glad you got it figured out. Now go drive the thing!