2.7 cutting out

[87911jon]

Thanks in advance. I searched the archives for CIS issues but didn't find anything exactly like this... I just bought a '77 2.7 911/CIS. At speed, every once in a while the engine cuts out. Comes back to life almost immediately. Can happen several times in a short period of time. Tach needle drops. Also, from time to time I'll get a backfire. Because it's so abrupt I'm thinking it's electrical. Ideas on what's going on? Jon

[schamp]

First thing that comes to mind is check and clean your grounds and connections pull your fues and make sure the ends are clean. Next change the fuel filter. Hope that helps.
Spence

[T77911S]

CD box is going bad. is it bosch or another type? mine was permaDOOM. i hear the new permatunes are much much better, still more than what i wanted to spend. i just put in an MSD for the same reason. the MSD is less than 200 without the rev limit and about 225 with. tough to find a place to mount though. i had to move the relay over on the relay panel and mount it there. if u want a pic, let me know.

[87911jon]

A picture would be helpful and great. Thanks.

[deanp]

Try checking the gap and condition of the points.

[azasadny]

Check your ignition and fuel delivery systems thoroughly... My problem was fuel distributor and Pertronix related... Good luck!

[Howard M]

Sure sounds like the points or the CD unit. Wait a minute! Do 77's have points? I don't think so. That leaves grounds or the CD box. You can make an adapter for an MSD box that allows it to be mounted where the present CD is, if you carefully bend the fuel accumulator bracket out of the way.

[deanp]

I thought the first year w/o points was '78. The Pelican catalog shows points up through '77. I'd check that first.

I had a jumpy tach, backfiring, etc and this was the cure for me. I eventually switched to the Pertronix Ignitor.

[zumwoll]

cars came stock with points thru 77 however maybe someone replaced with electronic. Clearly an electrical issue. DO a tune-up and be done with it. THere are so many vairables from cracked dist. cap , bad rotor, bad spark plug wire.

www.porschetuneup.com

[T77911S]

i would be driving and it would cut off and then back very quickly but very rarely. then it started doing more often and stayed off longer. i thought it was heat related because it drove fine until the CD had time to get hot, then it started doing it cold or hot.

[T77911S]

note the sideways relay. do check the basics first, but my moneys on the CD.
do u have a bosch or something else?

[RoninLB]

I had the same thing happen the first time the 911 was on the ET Hy.


I eventually flipped the coil and Permatune for a fix.


pic is not a suggestion, only entertainment.

[911quest]

Jon you have a pm

[T77911S]

interesting. i considered the back wall but didnt/have time to pull the motor. i may relocate next time i have to pull it. its a BIG unit and hard to find a mounting place.
whats some the other things u have mounted? kinda looks like something from a low budget sci fi.

[74-911]

Originally posted by deanp

I had a jumpy tach, backfiring, etc and this was the cure for me. I eventually switched to the Pertronix Ignitor.

Same for me. All problems went away after installing the Pertronix.

[RoninLB]

Originally posted by T77911S
interesting. i considered the back wall but didnt/have time to pull the .
whats some the other things u have mounted? kinda looks like something from a low budget sci fi.

Below the grey button is a lite that will tell if there is water in the Racor fuel filter. It needs button voltage instead of constantly on.

The black button triggers a 75amp Bosch relay for starter jump.

The square red is the tach adapter.

The round red is an ignition noise suppressor.

The perforated sheet gets fitted with threaded rivets for accessory mounting.

[zumwoll]

Creativity at its best !!

[RoninLB]

Originally posted by zumwoll
Creativity at its best !!

thx





and for 3.0+ dizzys I have this thread saved

MSD wiring advice (connectors)