want to change my 81 115hp from cdi to automotive

[81 charger]

Hello,
I have read some post on this topic and was wondering if someone could help with some pictures or step by step instructions on how to do this. I have the single cdi system with the belt driven distributor. Please help i have been having serious firing issues and i want a permanent fix to the problem. I have been having spark problems for the last two years and dont want to spend 300 bucks on a cdi just for it to last a year or so.

btw its a 81 chrysler 115 I believe the serial number is 115h1e

thanks

 

[Frank Acampora]

Re: want to change my 81 115hp from cdi to automotive

Your distributor has an electric eye. So, you must change the electric eye to points and add a condenser. This means finding a rotor with a cam, or buying a whole distributor set up for points. Not easy or cheap. A distributor will cost used as much as a CD box unless you are lucky. Better to find a 4 cylinder junker with a points distributor.

Then, mount a 12 volt coil--NOT a regular 9 volt automotive coil-- right where the CD box is. Run a blue wire from the terminal board near the starter motor to the + positive side of the coil. run a white wire from the - negative side of the coil to the points terminal on the side of the distributor. Run a longer high voltage wire from the center of the distributor to the center terminal of the coil. set the points to .014 open on a high lobe.

aside from finding the parts, it should take 1/2 to 1 hour to complete

Frankly, although a points and coil ignition is dirt simple I don't know why anyone would want to regress back to them--even if that person is having trouble.

You COULD retro-fit to a Prestolite non-distributor ignition which is more precise but again, finding parts will be expensive and it will take more work on your part to install.

 

[81 charger]

Re: want to change my 81 115hp from cdi to automotive

so you think i would be better off just buying a new cdi? The issue i am having is after 3-5 min of run time, idle or wot, motor shuts off because i loose spark. i can put the motor in a tank at home and it will sit and idle forever but as soon as i put it in the water and its under load it dies no matter where the throttle is at. When at home where i can use a volt meter everything seems to be where it should be but when it dies i have no spark coming from the cdi to feed the distributor. the cdi still makes its high pitched noise just nothing is coming from it.

thanks for the help

 

[Frank Acampora]

Re: want to change my 81 115hp from cdi to automotive

The CD box should not make any noise. This is an indication of something wrong with the electronics. Do you have the black, finned, Motorola box or a different unit?

The Motorola CD boxes can be found used. Look on craigslist, and ebay, they come up occasionally and I think a replacement unit from CDI costs around 200.

 

[81 charger]

Re: want to change my 81 115hp from cdi to automotive

mine is from cdi electronics part number 115-3301. makes a high pitched whining noise. i have heard that that is the sound they make when they are charging up.

 

[Frank Acampora]

Re: want to change my 81 115hp from cdi to automotive

Quite frankly, I have never heard one. The Motorola units are quiet.

Under load you will get more vibration that at idle in the driveway. Is it possible that you have a loose component or wire? Check everything including the ignition switch. Also, If your CD box wires pass under the rear of the flywheel, check them for rubbing.

 

[81 charger]

Re: want to change my 81 115hp from cdi to automotive

all my wires are good! i have pulled the flywheel and the stator is good. I am at a loss i cant figure out what is going on. Talked to some mechanics and they want me to bring it in and pay 75 and hour to let it sit in a tub of water. thee issue is it will idle all day in a tub and never cutt off. Last guy i took it to took it on the lake and what do you know it never died. picked it up he said it was fine went out on the water and 5 min and it cut out. im almost ready to sink the dang thing!!!!!!!

I have done some research and these cdi's do make a whining noise. If they are whining then they are working.

thanks for the help frank