Timing a jeep

NWA_CJ7 · 03-14-2008, 02:58 PM

Have never used a timing light before and was wondering if anyone has a link to or step by step intructions on how to time my jeep. It is the 258 and has the nutter bypass. I think the timing is off but want to check and make sure.

**Mike Romain** · 03-14-2008, 03:18 PM

It is basic. Get a nice idle, unplug the vacuum line and block it (though if it is ported it shouldn't matter) and set it to purr the best. Mine likes between 8 and 9 BTDC, others vary. A vacuum gauge can help dial it in. Go for the highest manifold vacuum and back it ff about an inch of vacuum. That should be real close to the best purr... Mine won't ripple beer in a glass on top of the air filter.

The Keith · 03-14-2008, 04:04 PM

Mine likes 8 BTDC, too. In fact, the "discoverer" of the Nutter Bypass recomends setting the timing to 8 BTDC and then tweaking from there.
Anyone feel free to add/help out if I miss a step...
Find the timing marks on the front of the engine. Driver side, next to the timing chain. ( I had to clean off the area and highlight the marks with a dremel). Let the engine warm up to operating temp and set the idle on your carb as to run the smoothest you can. Make sure the timing light is getting it's signal from the #1 spark plug wire, loosen the bolt holding the distributor and disconnect the vacuum advance from it. This works best with two people...carefully turn the distributor while aiming the timing light at the timing marks and set the timing to 8 BTDC. (The timing mark will be next to the #8.) You can then adjust up or down slightly and feel/listen for the jeep to run the smoothest. I found that I have to adjust the carb afterwards and then go back and re-adjust the timing.
Hope this helps and good luck!
Keith

JeromyCJ7 · 03-14-2008, 07:16 PM

You really don't even need to use a timing light. I just put my distributor in lastnight and pretty much set my timing by ear. Move your distributor till it runs rough then move it back till you get the smoothest idol. Your idol should be 8 or 9 hd rpms in nutral. Also once you get it set to the best idol take it up the road for a test run pay attention to you throtle response you shouldn't have any hesitation. That how I did mine and it runs awsome. Also I did check it with my timing light afterwords and it was about 8 BTDC.

**mmerlina** · 03-14-2008, 08:01 PM

I also set my new 258 to 8 BTDC.. runs like a dream there.

NWA_CJ7 · 03-14-2008, 10:02 PM

Thanks guys will give it a go

HighCountry · 03-15-2008, 08:16 AM

If by chance you get Spark Knock or 'ping' back it off about 2 degrees and try again.

I did mine by filling up with 87 Octane gas and advancing the timing until I could just detect pinging when I lugged the engine and then accelerated rapidly. Then I simply buy one grade higher octane fuel and consider it done! I checked it later with a timing light and it ended up being at 6 BTC....

Bruce

**Mike Romain** · 03-15-2008, 11:16 AM

Quote:

Originally Posted by JeromyCJ7

You really don't even need to use a timing light. I just put my distributor in lastnight and pretty much set my timing by ear. Move your distributor till it runs rough then move it back till you get the smoothest idol. Your idol should be 8 or 9 hd rpms in nutral. Also once you get it set to the best idol take it up the road for a test run pay attention to you throtle response you shouldn't have any hesitation. That how I did mine and it runs awsome. Also I did check it with my timing light afterwords and it was about 8 BTDC.

Your 'idle' should be 650 on the 258, 900 is screaming.

03-14-2008, 07:16 PM	#4
JeromyCJ7 Registered User Join Date: Nov 2006 Location: Charleston, SC Posts: 57 Profile Gallery Classifieds My Jeeps	You really don't even need to use a timing light. I just put my distributor in lastnight and pretty much set my timing by ear. Move your distributor till it runs rough then move it back till you get the smoothest idol. Your idol should be 8 or 9 hd rpms in nutral. Also once you get it set to the best idol take it up the road for a test run pay attention to you throtle response you shouldn't have any hesitation. That how I did mine and it runs awsome. Also I did check it with my timing light afterwords and it was about 8 BTDC.