Popped off Rotor...backfired and won't run
 

I'm a rookie so if I've done something completely stupid, please take it easy on me. I've got a 76 911 with a 2.7. Prior to what follows, the car started and ran fine.

I noticed what I thought was a section at the bottom of the distributor cap that had snapped off and that it might be exposing the distributor to moisture so I was going to put the old one back on until I got a new one. Having popped off the distributor cap, I decided to pop off the rotor as well to inspect. I didn't notice anything unusual and so put it back on. The chip at the bottom of the cap didn't appear to be exposing anything either so I snapped it back on - no wires removed, altered, etc - just popped off both the cap and rotor and put them back.

Went to start afterward... turned over for a few seconds with no fire. Tried again and it backfired loadly and will not start. Did I somehow screw up the timing? Does the rotor need to be aligned properly ( it did move when I popped it off and on). I also notices a couple previous posts that suggested the rotor be "snapped" down all the way - could the rotor not be pressed on firmly enough? Help!

Patrick

I've done this before.. you didnt get your rotor on correctly.. open it up and make sure it is seated in the "slot".

You may have chewed up your rotor cap too.. inspect.

Thanks for the quick response JP! I reinserted the rotor (definitely not on properly) but now it will not start- any ideas? Thanks again!!

Patrick

Check the cap carbon post . Check for debris in the distributor. Was it a rev limit rotor?

yeah what he said.. inspect everything carefully.. you might have tore something up.. do not worry you didnt do anything real bad. You might have broken the rev limiter on the rotor.. use a multimeter if you have one to check the rotor.. and inspect the inside of the cap..

Did the same thing and tore up my cap but it still worked..

Oh wait.. your car is probably flooded.. you can just leave it sit for awhile.. otherwise pull the plugs and dry them..

After a loud backfire.

Pull off the air box cover and see if there is something that looks like a miniature toilet seat just laying there next to a big hole in the bottom of the box. This is your pop off valve and could have come loose when it backfired. Clean it up and epoxy it back in place.

Thanks everyone for all the guidance - I had inadvertently severed a ground wire dangling around the distributor. Fixed the wire and its started right up! Didn't notice any damage in the distributor so I'm guessing I dodged that bullet but will have it checked out tomorrow. Thanks again!!

Patrick

Hopefully someone has installed a pop off valve and the air box is not damaged. Look closely at the air box in case the backfire cracked it. Any air leaks are trouble.

Good find Patrick..

make sure you have a pop off valve anyway.. will save you a TON of grief. Not to mention expense.

There is no reason to have it checked by the way.

Pop off looked fined - thanks again!

The point was to make sure you had one.. our year and some others are notorious for literally blowing up the intake.. so its good someone modified yours.. have fun driving.