Passenger side runs rougher than drivers side ...

66 CJ5 v6 2bbl Rochester Pertronix in a Delco, fenderwell headers dual exhaust

See video below, but my passenger side seems to run rougher than my drivers side ... and I get a shotgun shot of a backfire through the exhaust every so often (once tonight in 30 mins of running) ... Seems to be when coming off of the throttle/decel.

New cap, rotor, coil, plug wires and plugs, timing 5BTDC with vac adv disconnected

http://youtu.be/5ka3vGy65E8

 

Pls no comments on the wiring ... EZ wire kit coming soon to replace PO's mess ...

 

I've owned several Odd Fired Buick V-6 motors and none Idle like a true even fired 90 degree motor will.............reason is the odd fired pulse which in crankshaft rotation is 90-150-90 degrees. As you can see there is a large gap between pulse's.

Notwithstanding this is the same motor that you have had rocker issue's with that will translate into cam and valve timing issues which will translate into lazy valve actions which will translate into a valve not closing when it should and therefore having an incomplete burned charge in the pipe that's gets ignited by another ignition pulse which results in a Back-Fire.............I would not be to concerned about how well that motor runs based on the fact that it is wounded........Lucky it runs as well as it does.

 

Just my 2 cents. I had ran mine 180 out after I did my timing chain. The drivers side sounded what I thought as better with a deep tone to it and the passenger side was not as deep and had missfire. I also have same exhuast setup as you. Had very same symptoms also.

 

How did you fix? I pulled the #1 plug and when it's on compression (thumb over the hole method) when the timing marks line up, my rotor is at #1 tower ... Doesn't that confirm I'm not 180 out?

 

I'd bet you have the wrong dist cap. Did it run better before you replaced all the tune up parts?

 

If it was 180 out, it wouldn't run at all.
Where is your #1 spark plug wire located in relation to the vacumn advance?
Yes some caps come with info cast in them.

 

Cap and part number I have:


CJ5 Distributor Cap by Troy Davis, on Flickr


CJ5 Distributor Cap by Troy Davis, on Flickr

In case you can't make it out in the pic, #1 wire is at bottom left in between the left cap screw and the dwell window. #5 wire is up at vac advance.

What's the actual physical differences between the good cap and the wrong cap? Anyone have a list of known good part #'s? Napa RR189? Others?

 

Duplicate

 

Can you get in to adjust the dwell through the window?
It looks like a different version than the ones I have, even the hold down screw is diffferent.
What does the rotor look like? Long "tang" on the end?

 

Using pertronix - no dwell adj needed.

Yes - Rotor has long L tang ... http://shop.advanceautoparts.com/p/...6/20170388-P?navigationPath=L1*14923|L2*15034

 

take out the idle mixure screws and blow compressed air into the holes in the carb,,,,,use a blower nozzle with a rubber tip

 

442, will do. But I think the cap may be the issue. I looked on the napa site and the RR189 cap has the towers in a different location relative to the screws and the window than the cap I have.

Uncamonkey, do you recall brand and part number you have?

Advance shows a different part number for a '67 Skylark with a 225 and it looks like the napa RR189 - both different than the cap I have. Why would they be different? And why would advance, napa (lists rr184), and oreilly all list the wrong cap?

 

Some caps on the 225 are different,

Napa had two different ones, and it moves the sight window around. I got the wrong year once, even though computer said it was right. I want to say 67-71 uses a different cap than 66. Then add the fact some buicks had a prestolight distributer. (Not sure if that would matter) in your case don't worry about the prestolight thing.

I don't think the plugs on the cap being in different spots matter as long as they are right spacing and right firing order.


Sent from my iPhone using Tapatalk

 

With the odd fire engine, you have to be careful when setting up the distributor. As I try to describe this, I'll use a points activated distributor, but just think Pertronix spark activation when I mention points.

With an even fire engine, when you look at the distributor cam that opens the points, you'll notice that the cam lobes are evenly space around the circumference of the cam and it doesn't matter how the distributor is installed, as it will send a spark at evenly spaced intervals. This is not the case with the odd fire engine. If you look at it's distributor cam (it should still be present beneath the Pertronix magnet ring), you'll notice that the lobes are spaced at odd intervals around the cams circumference and it will send a spark at oddly spaced intervals (hence the name "odd fire"). There will be two lobes, spaced relatively close together, followed by a delay before the next two closely spaced lobes, and so on. When you set up the distributor, you have to make sure #1 piston is at TDC of it's compression stroke, then install the distributor so that the lobe activating the points at that time (keeping in mind the direction of distributor rotation) is the second of two closely spaced lobes (or in other words, the lobe before the delay). Then make sure the plug wire for cylinder #1 is installed at the distributor cap terminal that the rotor is pointing at, followed by all of the other plug wires in proper order.

If you by chance get this wrong, the cylinders on the drivers side (#'s 1,3 and 5) will have proper timing and will run smoothly, but the passenger side cylinders (#'s 2,4 and 6) will be poorly timed. They may produce some power, but will be very weak. Your symptoms sound like this may be the case.

If your distributor is set up properly, my next guess would be a poor fuel mixture on the right side of the engine. Unlike many engines I've worked with in the past, the stock Dauntless V6 intake manifold does not mix the two barrels of the carb to feed all the cylinders. The right barrel feeds the right bank, and the left barrel feeds the left bank. If there's a restriction in the right barrel's fuel circuit, it could be feeding a lean mixture to the right bank that's too lean to fire properly.

Good luck with it.

 

Makes sense - will take it apart and look at it this afternoon.

 

Re: the different caps ... obviously the rotor tang position relative to the cap tower is different between the two when the spark happens. Still not sure why auto parts stores spec the wrong cap unless there are different Delco bodies and mine looks like it is a replacement ... Def will try the other ('67 skylark 225 v6) style cap ASAP.


Distributor caps - differences by Troy Davis, on Flickr

Differences in Napa RR184 and RR189 are similar to the differences in the BWD caps.

 

I've seen two different set ups of distributor cap. I've seen one where the spark plug wire terminals are oddly spaced (like the cam lobes on the distributor cam) and the rotor has a straight tip. This type has to be indexed in a way similar to the distributor points lobes I described in my earlier post.
The second type that I've seen had evenly spaced spark plug wire terminals and a rotor with the long, sweeping tip. With this set up, indexing the cap is less of an issue, as the long tip on the rotor makes up for the odd firing of the ignition.

 

I can assure you it will run. I was 180 this is it at idle now corrected and in time. Little choke so about 900rpm idle.http://youtu.be/hBxILsOeWrU

 

The caps I have each have a small plastic tang on the inside of the rim that fits into a notch on the distributor body to locate the cap. The C175 cap shown above won't work on my distributor because the hold downs do not line up correctly ... Hold downs on the C169 do line up correctly. Still doesn't mean the C169 is the right cap, but Advance and Oreilly both say it is.

I have distributor 1110342 -looking that up I think the C169 cap is right.

I was able to borrow an infrared thermometer and the temp on the exhaust header is about 100 degrees cooler on the pass side. When feeling the exhaust out the end of the tailpipe, the drivers side is very warm, pass side feels cool. Plugs on drivers side look very good. Plugs on pass side are fouled rich.

I did pull the intake this past weekend and used new gaskets when I re-installed ... I was very careful, but could I have possibly put the gasket in wrong? I went out and double checked it again and the "ear" on the gasket is to the front on the drivers side and the back on the pass side. Looks right.