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.