Running rough after rebuild
 

Looking for opinions and just thinking out loud.

Complete teardown/rebuild. Car started instantly and then stalled. It did this a few times before it would idle. Took it for a ride and it ran rough and stalled if I let the revs drop.

Any ideas?

Thanks
Rod

You need to supply more imfo on everything for anyone to chime in.

Only the internals/mechanical were worked on. Intake, wires etc. were removed and put back on without changing anything. I checked all the wiring and vacuum hoses and everything looks fine.

My next step is too remove the plugs to see if they tell a story.

Simply put: Air, Spark, Fuel. My bet is on a massive air leak but I know nothing of new fangled stuff like 3.2's. I'm a little sketchy on the older stuff too. :)

I think what Mr. Zedsn is trying to say is that, other than a small hint in your signature, nobody's real sure what you have here. Your Carrera? Stock 3.2 Motronic to begin with? Did you rebuild with OEM replacement parts, no changes to anything like displacement or compression? Did you do the work? That sort of info...

Thanks tharbert

1986 911
3.2 bored to 3.4
964 cams
lightened flywheel and clutch
B&B headers
OEM parts

all the intake is stock

I did all the work myself other than buttoning up the long block. I had a professional engine builder do that while I assisted.

Massive air leak? I did remove the cruise control at the same time and plugged up the small vacuum line. Is there another one I missed?

I don't think I plugged this one.

http://forums.pelicanparts.com/uploa...1464110636.jpg

After doing a search I have found that line is a vent. :(

Did you get a chip to matched larger dispacement and 964 cams?

Plug wires connected correctly?
Timing?
fuel hooked up correctly?
Start with the easy stuff.
then
Cam timing etc

Chris

Lightweight flywheel during rebuild or before? If during, hold the throttle open a little during startup to keep the RPM's up

Same chip.
I checked plug wires and reconnected the distributor cap.
Will be triple checking everything tonight as I'm pretty sure it was something I messed up.
I'm going to pull the plugs first so I can confirm they are all the cylinders are the same or if one is the culprit.

Lightened flywheel during rebuild

I had the timing checked and this is what they found.

Idle - 3 degrees advanced
2,000 rpm - 29 degrees
3,000 rpm - 47 degrees

Thoughts anyone?

Way too much advance.

You car can run acceptably at half of 47 degrees. No 911 is at almost 50 degrees advance.

Looks like you are onto something.

Tell us about distributor work/fiddling. Also, are you ABSOLUTELY certain you have the plug wires on the correct cylinders? This is a common eff up where folks think they got it buttoned down tight as a drum but they make a mistake. Happens to all of us.

All looks good?

http://forums.pelicanparts.com/uploa...1465505699.jpg

http://forums.pelicanparts.com/uploa...1465505762.jpg

Nope - you lucked out. This is the problem.

Don't start till aligned properly. Ill post a pic in a second.

Your car is on TDC. Cool.

Pull dist and shift the ROTOR one or two notches to the right. That would be the gear at the base of the dist. CCW.

Then dial the body in to where the mark is close to the rotor tip.

You are aligned on cyl 6 to fire #1 TDC. Timing has been wonked about to kind of make it run. Get the rotor to fall at the black mark after you pull and reposition.


http://forums.pelicanparts.com/uploa...1465507435.jpg

I'm feeling good about this!

I thought the right side of the rotor had to line up with the notch in the dizzy?

I thought so too - pretty sure the way you have it in your photo is how my 3.2 was positioned when I took it apart...

This is based on my SC position. It is a CCW rotation.

Older CW rotation distributors position #1 in the same place. Lemmie get some pics. On the up side if I am full of **** it won't take long to get things straight.

Thanks for this help Bob.

Above you say "Pull dist and shift the ROTOR one or two notches to the right. That would be the gear at the base of the dist. CCW."

Right or counter clock wise?

Here is a pic of a 3.2. It appears to be a CW rotation vs CCW like my SC.

The position of your rotor appears pointing slightly towards the center of the of the engine, instead of slightly to the rear of the car.

Plus your rotor should be almost dead nuts in the center of that line at TDC. That is more than 3 degrees.

http://forums.pelicanparts.com/uploa...1465511757.jpg

I say one tooth CW (to the right)

Here is the SC location of #1. My black mark looks a little too far to the right.

http://forums.pelicanparts.com/uploa...1465512365.jpg

When I rotate CW 1 tooth it goes past the notch. Where it was before when you loaded up the rotor it is dead nuts to the notch.

The 3.2 isn't adjustable.

One tooth. The angle of the shot makes it look almost on but it's way off.

http://forums.pelicanparts.com/uploa...1465513788.jpg

Thank God you have the ability to do this.

I eat crow and my hat for leading you astray and I see where it cannot be moved.

Why 47 degrees Before tdc, though.

I won't ever "advise on a 3.2 again". My hit rate sucks. I apologize.

All good Bob. Lol
You did have me running out to the garage.
So this leaves the flywheel sensor. Is it possible to install a flywheel wrong?

Ferrino - thank you.

One more thought. I am so going to deservedly get beat up.

Twist the rotor CCW. How much does it move.

Check your wires.

Are you running the stock chip with all those mods? Seems like that could cause some problems.

Rotor doesn't move at all CCW. It loads up the cams (or whatever they are called) inside the dizzy when you turn it CW.

You can't mix up the wires as they only go on one way. But ya, I checked it like 10 times.
Wouldn't it be backfiring if the wires were wrong?

It's a stock chip with some mods.

The problem is the timing. Does a chip effect timing? Everything I see the timing is set mechanically.

The culprit?

http://forums.pelicanparts.com/uploa...1465757547.jpg


http://forums.pelicanparts.com/uploa...1465757567.jpg

I have to think the movement on my 81 is from the vacuum advance and retard mechanism in my 81. Does not appear to be the case on your distributor because you don't have a pod (correct?) Mine moves maybe 1/2" at the tip of the rotor.

I don't understand the time sert location.

Note no advice. Just interested.:)

84 and up have DME (Digital motor Elecrtonics) and there isn't any adjustment at the dizzy. The DME fine tunes the timing using a reference sensor on the flywheel.
The pictures I have shown above is the pin on the flywheel that the sensor picks up.
Somehow it is damaged. I'm wondering if I didn't install my flywheel correctly and it has become damaged.
We have pretty much come to the conclusion that the dizzy is in correct.

The sensor smacked the pin, take a look at the sensor, if damaged, you will need to replace both.

Buddy up north just went thru this.

http://forums.pelicanparts.com/uploa...1464911859.jpg

Draco. Can I ask what his symptoms were?

I was thinking that the sensor hit the pin as well until I found this before photo. The pin in the new to me, used, flywheel was already damaged.
You can never take too many pictures.

http://forums.pelicanparts.com/uploa...1465823627.jpg

Normally, that pin is an allen head bolt. Yours looks like a set screw, not that it would make any difference if the height is the same.