78 Traga misfire

[JLW]

Need a little help.
First of all I have included a picture as I hear is (required) for help.
I have owned this car for about 20 years but have not driven it much, and not at all for the last 3 years. When I went to move it, would not run.
It has MSD ignition and I just installed a Bitz Racing fuel injection system. Starts right up now but at idle only runs on 5 cylinders. Connected timing light to each plug wire to find which cylinder was bad and it was #6. I adjusted the timing and checked again and now the non firing cylinder moved to #3. Does this make any sense?
I’m not sure if this is something I did with the injection install or if it is from car not being started in three years.
I just don’t know where or how to get started looking.
Please help,

James

[JLW]

A little more information.
New plug wires.
New distributor cap and rotor button.
New spark plugs.
New fuel pump and filters.
I have cleaned gas tank and all fuel lines.
I have driven my car around the block a couple times, seems to run ok until I go back to low rpm and then has a constant miss.
I installed the MSD about 15 years ago and always ran fine with it. Just after I let the car sit for 3 years I started having this problem. There is a lesson to learn, Drive your car, enjoy it, don’t let life get in the way!

Again thanks for any help
James

[targa80]

How has the car been stored for the past three years? Do you see any moisture or arching trail on the inside of the distributor cap? I would suggest making sure all of the ignition wires contacts are dry and not corroded. The change of no spark from cylinder 6 to 3 says to me that the issue may not be the physical ignition wires from the distributor but more likely the distributor cap or before it. If you start the car at night with no lights on do you see any arching from the distributor wires.

[targa80]

Did not see the post on what you have done so far. In your post you say you did isolate the issue to no spark on cylinder 6 and then you adjusted timing and the no spark is now on cylinder 3. Is this analysis still true? If it is then you are probably arching the high voltage to ground prior to reaching the plug.

[JLW]

Unfortunately my car sat outside, so yes it was exposed to the elements. I have not tried it at night, that is a very good idea. I will try that tonight and watch for arcing.

I did try an older set of wires I had, just to see if anything changed, but had the same result.

James

[Targalid]

Or maybe you mixed up the spark plug wires Check your wire order carefully.

[JLW]

Just checked firing order and it is correct.

[theiceman]

You are aware firing order on an sc is based on rotor going ccw right ?
You adjusted timing based off cyl one right ?

I know sounds dumb but worth asking

[JLW]

Yes, I realize that, and there are no dumb questions when it comes to me. Please bring up all possibilities.

[timmy2]

New plug wires not fully seating well in the new dizzy cap?
I’ve had them pop out. Center one in my case. Could be why the problem moved when you adjusted timing.

[theiceman]

i just helped a guy who was misfiring after installing clewits. turns out he had the rubber over the plug at the plug end. we peeled it back put it on and away she went .

I did not like the wires at all , did not " snap on" the plug like my OE wires at all.

[JLW]

I have tried three different caps and three different rotor buttons in different combinations so wires have been off and on multiple times always with the same result.

Just drove around the block again and engine backfired a few times, sure glad for the pop off valve.

[timmy2]

Maybe you need to run an auto tune and adjust your map with all the new components installed.

[RedCoupe]

Originally Posted by theiceman

i just helped a guy who was misfiring after installing clewits. turns out he had the rubber over the plug at the plug end. we peeled it back put it on and away she went .

I did not like the wires at all , did not " snap on" the plug like my OE wires at all.

+1 on the Clewitt wires. I just made a post on another thread about a set I just bought from our host. Wish I had bought OEM style wires.

[JLW]

My wires are Magnecor. Had them for a while, but no miles on them. There is a nice snap when plugged onto spark plug and have checked distributor end to insure all the way in.

Just moved some wires around from the MSD and seems to run a little better. May have a ground somewhere on one of them. Still looking.

Have not run auto tune, still trying to learn how, just using tune that came on kit from Tony since we both have 1978 SC, hoping it is close.

[Bob Kontak]

Originally Posted by JLW

Just moved some wires around from the MSD and seems to run a little better. May have a ground somewhere on one of them. Still looking.

Steve at Rennsport Systems suggested I install MSD vs my Permatune silver box back in the 1800's (plus or minus a few years).

What he stressed was to go fully anal retentive on the grounding of that system. He likes those lock washers with the teeth in them, for instance.

I took my ground to the main lug under the car by the transmission and used the tooth washers. Mind you, I installed my MSD box under the driver's seat so the choice of the central lug was not that big a deal.

I don't like that your misfire moves around from a conventional diagnostic approach. My first though was the same as Targa80's. You are shorting to ground in the secondary side of your ignition and it's a function of which secondary wire is firing off to a ground. (I have never seen my Clewetts do this and I bet Magnecor will not either if connected properly. Oh, My old Beru's would)

However, after you mention moving the MSD wires around the Rennsport Systems suggestion popped into my head.

[targa80]

Have you had a chance to look closely at the wiring at night while the engine is running?

[JLW]

No I have not. Been out of town. Leaving again this morning. Busy time.