88Dutchman

First day and I already have a question. I did a search but found nothing that describes my exact issue that I may or may not have.

I popped off the distributor cap the other day to notice that it was filled with oil. Being the engine has 246k on the clock and the stock distributer I figured the shaft bushing was gone and it was time for a new distributor. Keep in mind it ran fine with the oily distributor. Felt a bit tired but still ran with no issues.

So I pulled out the old distributor and doing so noticed the typical old school distributor hold down clamp bracket. I thought it was odd because the timing is computer controlled on my 88 xj.

Put the new one in but I noticed that the new one had a cast location hold down brace on the distributor shaft. Of course I made sure the rotor was in the proper location when installing it again.

Cranked it over and nothing. After about an hour of checking everything over I looked at the old distributor shaft to notice that under all the grease that cast on location brace was sawed off as well!

So I rotaded the new distributor body to the same location the old one was at and it fired right up.

It's about 20 degrees clockwise to where the "spec" location is.

To be honest it actually runs better now than even before the old distributor was pulled.
Starts better too.

So what's the deal?

Sorry for the long winded write up but I just wanted to be clear.

Thanks.

cruiser54

Click on the link below. My Tips.

Read Tip 12 and perform Tip 13.

DFlintstone

Keep in mind that the books a diagrams are wrong, #1 is at 5:00 viewed from the side.

The front tube on the valve cover needs to be free to vent. If it's not crankcase pressure can cause it to blow oil out where it can...even the dizzy I suppose.

cruiser54

Tip 12 shows that.

You guys need to familiarize yourselves with this also:

Distributor indexing explained


For clarification though, that's not a cam sensor inside the Renix dizzy. It's there to fire the injectors sequentially with the firing order. You'll never notice if it went bad because the ECU will try to "guess" where it is and does a heck of a job at it.

As for the "timing", it is controlled by the ECU. Ever notice how wide the tip of the rotor is? Try and wrap your head around this:

When the ECU yells "Fire" to the ignition control module, where is the rotor in relationship to the dizzy terminal? Not to the terminal yet? Past the terminal too far?

What happens to the spark/secondary ignition strength when it has to jump the Grand Canyon in comparison to shooting from a rotor tip?

Tip 13 gets the thing right. Use Tip 12 first to guarantee you're on #1 TDC.

DFlintstone

I"ll bet it sensing the position of the cam also let's it fire the correct plug sooner as well.

Duchman a whole bunch of what I know about Renix Jeeps came from Cruiser. It just humors me to raz him a little sometimes!

cruiser54

That dizzy could care less about cam timing.

DFlintstone

Interesting. So the ECU knows when to fire an injector but doesn't share that with it's self to fire a plug? I'd think with the pulsssinkerator working both would get the news.

88Dutchman

Wow, thanks guys. That makes it a lot clearer. I must of just got lucky and got it in the right general location. I'll confirm the TDC to rotor location this week again to make sure I'm good.

cruiser54

Wow, you got through all that in spite of Flintstone's jabbing me?

Good plan BTW.