SAVAGE
Member
- Location
- Richfield Utah
Well I decided to do a quick write up of tonight's project. My dad has a '78 CJ5 with a 304 and 3 on the floor. We have been having a ton of issues lately mostly dealing with our ignition system. As some of you may know the stock prestolite system is less than desirable, or in my own opinion a worthless pile of crap. The biggest issue we had is starting the jeep. Sometimes it would fire up, sometimes no way. Well we eventually figured out that it would just crank and crank and right when we let off the key it would fire and almost start, or even sometimes start. This was because the ignition system runs at 9 volts or something like that. But when you start the motor it is supposed to bump the voltage to 12 volts to aid in starting. Well I think that we had a bad ignition module or something else we never figured out that was severely limiting our voltage on start up. Not only these problems but the jeep was also slow (for a 304 v8 anyway), sputtered and stalled at full throttle, and idled really rough.
So we replaced the spark plugs,
new wires,
new cap and rotor,
new coil,
chased down and tried to fix wires,
rebuilt the motorcrap carburetor,
got a new holley carburator,
chased down vacume lines,
plugged off some emmisions lines,
Well it went on like this for sometime and we could never fix it. Our only option was to completely go through the ignition system and possibly spend hundreds of dollars to permanently fix a stoopid prestolite ignition system. Or we could spend our money once and upgrade our ignition system to HEI and never look back. Well my dad and mom went on a jeep ride the other night and broke down (no spark, big suprise). I got called to come rescue them and give them a tow. I told my mom I will only come tow them to town if she lets dad buy a new distributor.
So...
We also had to get the new spark plug wires with female ends on both ends for the HEI plugs. Plus the 8mm will help handle some of them 55,000 volts
It was a pretty simple procedure overall. I marked where plug #1 was on the old dizzy cap and took it off. Then I marked where the rotor was pointing and i pulled the whole thing right out.
The new DUI distributor went right in without much of a problem. It cleared the power steering pump easily, however we had to loosen the fuel coming from the top of the pump and turn it a little to the driver side fender. Other than that it worked good. I also turned it so the vacuum advance port was pointing to the front of the jeep rather than at the power steering pump. This gave me more room for the 12 volt ignition wire.
Now a word of advice. I highly recommend putting the old distributor/cam gear on the new distributor. If you use the new one the gears will not mesh properly and might turn into a bomb of metal shavings to be pumped throughout your entire motor. If you must use the new gear you must also install a new cam gear also. Which would be a lot more work than doing what we did. All we did was pound a pin out, slide new gear off, slide the old gear on, put pin back in, measure to confirm depth. We also pulled the plugs and gaped to .55 thousandths when we where punning on the new wires.
And here is the end result after about 2 hours worth of labor and 350 bones to the parts people. Dad reached the cab in for the moment of truth and turned the key. He cranked it and it fired up instantly idling smoother than we have heard it run in years. I threw a timing light on it and we where at about 18 degrees (not bad for a guesstimate and putting in a new dizzy). I bumped it down to 10, connected the advance line and we went for a test drive. WOW! Our jeep runs so much better now that it ever has since we have ever had it. Way more low end torque, instant throttle response, and a significant increase in power.
Well hope you all liked it. If you have any questions I'll be happy to answer them.
So we replaced the spark plugs,
new wires,
new cap and rotor,
new coil,
chased down and tried to fix wires,
rebuilt the motorcrap carburetor,
got a new holley carburator,
chased down vacume lines,
plugged off some emmisions lines,
Well it went on like this for sometime and we could never fix it. Our only option was to completely go through the ignition system and possibly spend hundreds of dollars to permanently fix a stoopid prestolite ignition system. Or we could spend our money once and upgrade our ignition system to HEI and never look back. Well my dad and mom went on a jeep ride the other night and broke down (no spark, big suprise). I got called to come rescue them and give them a tow. I told my mom I will only come tow them to town if she lets dad buy a new distributor.
So...
We also had to get the new spark plug wires with female ends on both ends for the HEI plugs. Plus the 8mm will help handle some of them 55,000 volts
It was a pretty simple procedure overall. I marked where plug #1 was on the old dizzy cap and took it off. Then I marked where the rotor was pointing and i pulled the whole thing right out.
The new DUI distributor went right in without much of a problem. It cleared the power steering pump easily, however we had to loosen the fuel coming from the top of the pump and turn it a little to the driver side fender. Other than that it worked good. I also turned it so the vacuum advance port was pointing to the front of the jeep rather than at the power steering pump. This gave me more room for the 12 volt ignition wire.
Now a word of advice. I highly recommend putting the old distributor/cam gear on the new distributor. If you use the new one the gears will not mesh properly and might turn into a bomb of metal shavings to be pumped throughout your entire motor. If you must use the new gear you must also install a new cam gear also. Which would be a lot more work than doing what we did. All we did was pound a pin out, slide new gear off, slide the old gear on, put pin back in, measure to confirm depth. We also pulled the plugs and gaped to .55 thousandths when we where punning on the new wires.
And here is the end result after about 2 hours worth of labor and 350 bones to the parts people. Dad reached the cab in for the moment of truth and turned the key. He cranked it and it fired up instantly idling smoother than we have heard it run in years. I threw a timing light on it and we where at about 18 degrees (not bad for a guesstimate and putting in a new dizzy). I bumped it down to 10, connected the advance line and we went for a test drive. WOW! Our jeep runs so much better now that it ever has since we have ever had it. Way more low end torque, instant throttle response, and a significant increase in power.
Well hope you all liked it. If you have any questions I'll be happy to answer them.
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