#1 & #3 still dead from 2000 to 2500 on '83

[koonta]

Well I pulled the plug caps apart and removed the resistor, cleaned the insides,and replaced with copper wire. pulled the connectors off the TCI and cleaned em, checked plugs with ohm meter [like I knew what I was doing ha!] I don't remember what the reading were but they were the same, checked the plug on the left side of the frame rail-unhooked going to TCI it read 540 ohms except the w/g 512 ohms, going towards pick up coils there was no resistance, o. So with what I could find to clean I did, fired it up, warmed it still #1 & #3 are dead between 2000 RPM and 2500.? I really hate to just start throwing parts at it and try to hit something, really was hoping it was the resistors in the plug caps, any ideas?

[MiCarl]

How are you determining that your problem is with 1 & 3?

 

Your post gives me the impression that it runs fine below 2000RPM and find above 2500. Do I read that correctly? Or do you mean you have cylinder(s) dropping out as you wind it up?

[koonta]

Ya, runs great except between 2000 and 2500. I grounded plugs on the cases, one cyl at a time, and no spark on 1 & 3 between this rpm range

[MiCarl]

Wow! That is a puzzler. If you haven't, try with a brand new plug and make sure you still have the problem.

 

My guess is that it'd have to be coils or TCI. That is the range where the ignition advance starts to kick in, wonder if it's a failing TCI. Be interesting to watch with a timing light and see if it looks flaky when it is firing.

[bkuhr]

First suggestion would be to clamp timing light around spark plug leads of effected cylinder, fire it up, and verify you are really loosing spark in RPM range, by timing light quit flashing. If in fact not loosing spark, likely fuel/vacum problem at RPM range. If really loosing spark-below.

 

Dingy's wiring diagram states pick up coils should be 93.5-126.5 ohms.

1st would verify your meter = 0 ohms with leads shorted to each other. If your meter is sensitive enough, you will read .1-.2 ohms across the leads. Subtract this reading from any test results.

Read all pick up coils from 6 pin connector removed from TCI. One side of meter always on Black wire, and other meter lead 1 at a time on pickup coil as follows. You are measuring thru another 6 pin connector down near middlegear cover

Cyl#1=orange

cyl#2=grey

cyl#3=white/green

cyl#4=white/red

I think this sequence is correct, but could be wrong

 

If you still have all pickups still in 500ohm range, I would suspect you have corroded wiring problems, possibly at middle gear connector. If just 1 pick up out of range (2 cylinder per pickup-I think 1&2=one and 3&4= the other), I would suspect defective pickup worth trying to replace). Only other thing in pickup circuit is battery 12volts on each coil connector. Make sure 12v not going open at RPM for some reason on effected coil/s. Other than this you just have coils and TCI. Could try swapping coils and see if problem moves with coil.

 

Just had a thought. 2000 rpm would be in the range where pressure sensor is ordering TCI to advance spark, maybe pressure sensor is hanging in a dead spot, either defective or vacum leak, but would expect all cylinders to be affected by late spark.

 

Just my thoughts:2cents:

[koonta]

Thanks guys, guess I got more scratching to do!

[koonta]

new day, a little more awake, ohm reading at the plug on frame going TO the pick up coils is from 123.3 to 125.6, going from same plug towards tci those read in the 600 ohm range today, I did mess up tho, it does miss when it's cold , sorry, but the rpm when it starts picking back up is a little higher a little closer to 3000.

[MasterGuns]

You should start looking for another TCI or resolder yours. Perhaps someone can loan you a useable TCI as a test install (temporary).

[koonta]

I think your right MG, I think tomorrow I'll pull it and check it out

[bkuhr]

Think I would try swapping ing coils before considering getting/repairing TCI. If problem moves with coils, likely TCI ok.