retarded distributor

[cmcfaul]

I just rebuilt my 2.4.911 E. Runs great when cold. When warm the timing retards. I correct it and it retards more. I am out of adjustment and need to pull the distributor to advance it a tooth to get the correct timing at this point.

I replaced the cap and rotor with no change. I oiled the distributor (without taking it apart) and no change. It advances correctly. Is my distributor going bad?

I replaced the crank during the rebuild and took the old gears from the original crank and had them pressed onto the new crank. The distributor gear can't be slipping on the crank can it? Seem highly unlikely.

Any thoughts are appreciated.

Thanks,

Chris
73 911 E
MFI
Petronics breaker-less ignition.

[docrodg]

Probly needs rebuild. If I understand correctly you can set timing and check for advance and that works fine for a little bit then the timing point retards (still advances when revved). Loose cam in the disty due to shaft wear?

[unclebilly]

Consider this before you rebuild your distributor. It is cheaper and better to install a Distributorless Ignition setup.

I am running this on the chump car because it was cheaper and more reliable than fixing the worn distributor, again...

On ebay, you can buy a main pulley with a crank trigger from goingsuperfast. There are other suppliers that are more mainstream but exect to pay 2-3X more.

Buy a megajolt box - these are super easy to configure.

Go to a pick and pull type place and remove the EDIS box and the shielded wires from a late 80s / early 90s Ford Ranger. I am running the coil pack from a Chrysler minivan because the plug wire ends are not 'oddball' but I still had to change the coil pack ends on my plug wires. You will want a focus crank trigger.

All in, this cost under $400 and is way better than the stock setup. The tach plugged into the Megajolt box and worked.

If you do this, PM me and I will give you my spark curve tables. One is the stock 911 setup and the other is the RS curve.

This is also the cheapest way to go twin plug.

[E Sully]

You say it advances fine, but the timing retards when warm. Does the total advance at 6000 rpm retard, or just the idle setting?
What is the number on the distributor? The original distributor has a vacuum unit that is supposed to retard the timing at idle. It may be sticking or there may be a leak in the vacuum line or diaphragm.
Distributor Maintenance

[T77911S]

thats what i was going to ask about.
is there or was there a vacuum pot for timing advance or retard?
is it connected?
does it work?
even if you have a vacuum advance pot, the plate could be sticking and slow to return.

the mechanical advance could even be slow to return.

me? i would pull it aprt clean it up and give it another try. make sure you clean the places that are electrical, as in grounds.

[gptom]

On 72s there are 2 vacuum hoses to distributor. 1 is advance & 1 retard at idle. Part of the emissions package

Tom

[cmcfaul]

Just went for a long drive. Ran great going out. Dropped off an engine stand and on the way back ran like crap. Checked the timing when home and it's 15 degrees retarded.

It has vacuum retard (two hoses feed off the stacks into a single connection on the distributor) but is only applicable at idle. Crack the throttle and it advances 10 degrees instantly.

Distributor is about 10 years old.

Needs to come appart. Wonder if this is somthing I can fix or send to the experts.

Chris

73 911 E

[cmcfaul]

Fully electronic ignition is the way to go and would go in that direction a few years ago. However, need to keep it as stock as possible as that is where the value is. It does have Petronic Breaker-less ignition inside the distributor

Chris

73 911 E

[Steve@Rennsport]

Originally Posted by cmcfaul

Fully electronic ignition is the way to go and would go in that direction a few years ago. However, need to keep it as stock as possible as that is where the value is. It does have Petronic Breaker-less ignition inside the distributor

Chris

73 911 E

Chris,

Humor me,....pop the points back in there and test every thing again.

It may be worth your while to do this.

[tobluforu]

Originally Posted by gptom

On 72s there are 2 vacuum hoses to distributor. 1 is advance & 1 retard at idle. Part of the emissions package

Tom

Wait, what? On my 72 there are two vacuum hose teed into one, running to one port on the dizzy.

[T77911S]

Originally Posted by cmcfaul

It does have Petronic Breaker-less ignition inside the distributor

Chris

73 911 E

why dont people tell us things like this in the begining?

[timmy2]

Originally Posted by T77911S

why dont people tell us things like this in the begining?

You are expected to know it just like the Amazing Kreskin would...

[E Sully]

He does have it in his first post.
Steve has a good idea on the points. It will give you an idea if it is the Pertronix.
What is the number on the distributor?

[unclebilly]

Originally Posted by Steve@Rennsport

Chris,

Humor me,....pop the points back in there and test every thing again.

It may be worth your while to do this.

Yup, I had to do this with my 77 when the Pertronix crapped out. The Pertronix has never been put back in the car.

It seems that the pertronix rubs on the early rotors with the 7300 RPM limiter, they get hot and act up and eventually quit.

I still vote for a distributorless setup. Keep the original stuff for the next owner you are saving the car for, but enjoy the drivability of the modern ignition.

[T77911S]

Originally Posted by E Sully

He does have it in his first post.
Steve has a good idea on the points. It will give you an idea if it is the Pertronix.
What is the number on the distributor?

i had to read it 4 times before i saw it at the bottom, and that was after you said it was in the post. still, someting like that should be in the post.

[cmcfaul]

I cring at the thought of putting points back in. I don't remember how to connect them and the dwell meter it's been so long.

Tell me more about the Petronics issue as I have the 7300rpm rev limiter. I have had it in there for many years and has worked perfectly.

Thanks all

Chris

[unclebilly]

My old pertronix had a visible rub mark on the top of it and you could see that it had been hot.

Pull off your rotor and the plastic cover and have a look.

You can set up your points close enough to test this theory with a set of feeler gauges.

[fanaudical]

There are numerous threads on unexpected Pertronix behavior. I think most common reports the Pertronix unit having inconsistent timing from cylinder-to-cylinder. There have also been some anecdotes of other unexpected behavior seemingly related to temperature.

If Steve W asks to check that first, I'm speculating it's because he's seen enough of it first-hand to want to rule it out immediately.

[cmcfaul]

I ordered a new pertronix kit...only $100 and I can install much easier then relearning how to install the points.

The Pertronix uses a magnet and the way to demagnetize a magnet is to heat it. I am thinking 15 years of heat cycles has caused the magnet to loose strength. Will see.

Chris
73 911 E

[cmcfaul]

The number on it is 231 184 004
JFUD 6

I looked it up and appears to be for either the 73 S or RS after 5/73

I took it appart, cleaned it, put it back together and no joy. Guess it has to go out. Not really in the budget right now.

Chris

73 911 E