435hp TI problem?

[vigman]

Cheesy.. but good ( spark viewing)

If your a frady-cat of things electrical.. do the following.

NOTE if there are fuel fumes lingering.. do NOT do this.. and dp it in a WELL VENTILATED AREA!

( but dark if possible)

Go to your local auto parts store.. in the tool rack they have a thing..that looks like a spark plug with a clamp ( big alligator clip ). Get this to bite on a good clean piece of metal!

Hook a plug wire up to the other end of this device.. have an assistant crank the car over, while you watch under the hood.

You SHOULD see a nice FAT white- blue spark jump across the gap... and hear a tic-tic as the spark jumps.

If it's yellow or whipmy.. you have a problem!

Now if you have NO FEAR of a 20KV pulse.

( and if you get zapped.. it WILL stun you!)

Grab a spare plug.. and make your own test tool just by wrapping some wire around the threaded ( clean) part of the plug.. and grounding it.

Then put the plug wire on the tip.. repeat procedure!

Vig~

 

[67stingray]

Vig, Over the years I have been zapped by grabbing plug wires and other dumb stuff like that. Its not any more fun than it was 30 years ago.I just cant get used to it. I will try you suggestion. Do you know if a coil can get weak or it is either good or bad. Thanks Don

 

[vigman]

Yes coils can go bad

Over heat, time,age they can get el stinko!

BUT I would check the TI module.. it would be MORE likey for the final transistor to go KAPUT!


Vig!

 

[67stingray]

I am El dumo when it comes to elec. How can I check TI mod, can it be fixed or is replace the way to go.

 

[Milehigh66]

Stingray67,
T.I. units use a different coil than points, make sure you use the correct one.
Before I got fed up with my T.I. unit and replaced it with a pro billet dist from msd I had alot of the same problems you are having. I tried using one of the sealed after market replacement modules but it wouldn't start correctly with it in. I even tried a couple different carbs thinking that was the problem but it still would foul the plugs (not saying that you don't have a carb problem, you may have from what you have said.) Check the wires into you dist very carefully, they tend to get brittle over time and the insulation breaks. Make sure that your module is well grounded, I believe if I remember it is grounded to your radiator support. If the module is not grounded well it will not work or if it is corroded it will work but not very well.
Also pull your dist cap off and look for dust or metal dust, it is a magnet after all and will pick up everything.
I know that people say that they just go bad and there is no middle ground, but my experience and recently Jeffs (Blkblt) have been very different. His started miss firing at higher rpms as well.

Hope this helps
Kurt, CCC

 

[Milehigh66]

I am El dumo when it comes to elec. How can I check TI mod, can it be fixed or is replace the way to go.

I don't know of anyone fixing these, so replacement is I believe the only option. You can check the ground and the wires by taking it out. It is located on the drivers side next to the radiator, the bolts that hold it in go through the wheel well in front of the drivers side front wheel. They tend to pick up a fair amount of moisture because of the location and the plug that goes into the module can get pretty corroded, so make sure to clean it up well.
Then when you get all of that done go buy a pro-billet dist and msd box and start enjoying your car, put the T.I. unit in a box for someone else to worry about.

Kurt, CCC

 

[67stingray]

Kurt Im gonna try to keep car original till it pees me off to the point of poop-canning the dist I tore the car apart and rebuilt it starting in 88. I bought a new TI unit and harness at that time.Last week I did rebuild the center carb and replaced the wires and cap,plugs. What you said makes sence. It has to be a connection or mod ptoblrm When I put the car on jack stands is when problem started. Maybe the flexing disturbed the ground. That will be my next chase. thanks Don

 

[vigman]

Well, I would do the following

Do the spark check first.. if the spark is big & beefy.. then the problem lies elsewhere like the carb.. or timing.

But if it IS whimpy.. then we have narrowed things down.

Start working you way back, pull the cap off and look at the rotor ( you did replace the rotor when you did the cap... right?) No black pitted ends on the rotor ends spring in middle making good contact ...right? No bronze dust right?

No stuff in the place the reluctor sits ( the star looking thing where the points cam used to be) or the pick up coil.

Next remove the TI module ( MARKING THE WIRES FIRST) and clean the ground points & the connectors use a GOOD quality electronic contact cleaner, then re assemble.

Next remove the coil wires one at a time.. inspecting the terminals and cleaning again.

Is there a capicitor hanging on the coil for radio noise supression? try removing that.

Next, just replace the center wire from the coil to the Distrib..

And try test 1 again.. any better..

If no
See if you can Borrow a TI module and or coil from one of our other fine members.

And Mile High is 100% correct the coil IS different.

Vig~

 

[vigman]

Oh yes.. another thing

When the car is in START.. it gets 12volts to the positive side of the coil directly from a stater solenoid contact(R) ( might want to check that is tight,


.. when in RUN.. it has a piece of Ni-Chrome wire acting as a ballast resistor..limiting current to the coil. ( but I can't see an indication on my 64 schematic.. but I know it's there in my 73)

THIS IS FOR CONVENTIONAL IGNITION WIRING


But..I'll BET it's the same for the TI setup..just with different power & ground to the actual module.

The point is you want POWER at the positive coil in RUN & Start.


Vig~

 

[Milehigh66]

I agree, check the ground and work your way through the wires.
I can appreciate keeping it original, when I bought my car it was definately a survivor, all original. On the other side I really like driving my car and want it to be reliable, so I have replaced the parts that can be put back on relatively easily, but I am not showing or having my car judged.
If you think it is a dist problem and need to borrow my parts that I took out let me know, I would be happy to send them to you to try, maybe you could eliminate some of your problems. I know that my dist is in good shape because Lars rebuilt it before I took it out. I do not believe however that my module is any good at all.
Your ground is the place to start though.

Kurt, CCC:J

 

[67stingray]

Thanks Yes I did replace rotor but didnt spend time looking at prongs on dist. shaft.Need to revisit. Ill check coil then will try connections at module. Dist. was new in 88 and probably 5000 miles ago. Would doubt thats it. but... More snow commin ,I will chase next week. Great Ideas!!!!

 

[67435animal]

Sure sounds like a carb problem to me. But, since I have a TI system also, let me tell you what helped hard start and improved performance dramatically: NGK Spark PLugs #4722. They solved a number of problems for me. Once you get your carb problem resolved, try a set of these. They are available (usually you need to order them ) at Advance.

Bob

 

[vigman]

Some further tests

My best guesses of the day!

First will the car fire when you blast some Quick start down the center carb throat?

AND, I assume the plugs are all good
( you've pulled a couple of em out and they are NOT black & fouled) and I further assume you know how to use a 12volt test light.

My coil POOPED out on the boat this weekend... which got me thinking about your problem... here are some easy tests...

Do you have an OLD school dwell meter? Get it, dust it off.. and hook her UP!

As your cranking, your dwell sould be 28 to 35 degrees..( under 50 is ok). This is the duration that the TI is pulsing the negative side of the coil... If this isn't happening your TI module is shot!
( or bad connections, grounds etc.)

No Dwell meter? BUY ONE at the local swap meet.

If you want to continue testing... get a test light... ( turn the IGN to ON) touch the test light to the POSITIVE side of the coil.. got power?

NOW touch the probe to the NEGATIVE side of the coil, crank the engine.. Is the light pulsing?

If yes, that means something IS coming out of the TI unit.. but you do not know how much action is happening. ( That's why the dwell meter is handy).

COIL TEST
Disconnect the negative side of the coil.
(tape the neg lead out of the way.. so it doesn't short out).

Turn the IGN ON
Test ( with the test light ) the positive side of the coil.. got juice? NOW touch the negative side.. got juice there too? Good..

If not..your coil has opened up on the primary side.

Vig~