1978 FJ40 - Starting challenges - power to the Distributor.. Electronic Igniter Assy (1 Viewer)

[otbkool]

Hello All,

New to the forum. New to my 1978 FJ. It was starting and running. I drove 3 miles to a store. It stalled at a stop light but fired right up (popped the clutch). After I came out of the store - it would turn over, I could smell fuel, but it would not fire up. Tried with the Choke, with out etc. Had it towed home.....

Here is what I have tried so far:
- checked all the wires to from the coil/igniter assembly to the distributor cap were connected and that all the spark plugs were connected
- checked that the ground was connected
- tested that the rotor was working
- replaced the coil
- checked the fuses
- tried using starter fluid in to the carb to make sure it was not a fuel issue

Leads me to believe that I may have a power issue from the igniter to the distributor.

My questions - Any other ideas on what I should look at? Any ideas on how to confirm that there is power going into the igniter assembly? Any other details I should add here to better help with diagnosis?
Thanks a million.
Olan

 

[Shark56]

Pull plug wire.
Hold near block to ground. (Use pliers to hold plug wire)
Have someone crank engine.
Look for spark.
That will confirm igniter working.

 

[DougAustinTx]

Actually, the above test is not conclusive. If the distributor cap is internally shorted, or if the rotor is shorted, (carbon tracks in tiny cracks in the phenolic) the spark will never get out of the cap, and the sparkplug wire will be dead. You come off better by pulling the high tension wire from the center pole of the dist cap, turning the engine over and see if you get a spark of a half inch or so when you hold the HT wire near the block, or the negative battery terminal. If you have a strong spark, then the problem is probably in the cap or rotor. If no spark, then check that the entire coil and ignitor are properly grounded to the inner fender. (Put a jumper wire from the coil bracket to the negative battery terminal). I noticed that one of the mounting bolts for the coil bracket is missing, Since your vehicle is nicely painted, you may have to scrape the paint on the inner fender to get a good ground, and be SURE to put that second bolt on the coil bracket to the inner fender. Your ignitor looks to be from a later model Toyota to me, maybe an FJ60 or 62? Nevertheless, if it was working before, the ignitor is not likely the problem.

 

[otbkool]

Pull plug wire.
Hold near block to ground. (Use pliers to hold plug wire)
Have someone crank engine.
Look for spark.
That will confirm igniter working.

Thanks - tried this - no spark whatsoever. Need to work farther up the chain - next post has some more ideas! Thanks for the help.

 

[otbkool]

Actually, the above test is not conclusive. If the distributor cap is internally shorted, or if the rotor is shorted, (carbon tracks in tiny cracks in the phenolic) the spark will never get out of the cap, and the sparkplug wire will be dead. You come off better by pulling the high tension wire from the center pole of the dist cap, turning the engine over and see if you get a spark of a half inch or so when you hold the HT wire near the block, or the negative battery terminal. If you have a strong spark, then the problem is probably in the cap or rotor. If no spark, then check that the entire coil and ignitor are properly grounded to the inner fender. (Put a jumper wire from the coil bracket to the negative battery terminal). I noticed that one of the mounting bolts for the coil bracket is missing, Since your vehicle is nicely painted, you may have to scrape the paint on the inner fender to get a good ground, and be SURE to put that second bolt on the coil bracket to the inner fender. Your ignitor looks to be from a later model Toyota to me, maybe an FJ60 or 62? Nevertheless, if it was working before, the ignitor is not likely the problem.

Hi - thanks for this review. I am not getting any power to the high tension wire. There is power at the ignition. the starter is turning. I do not seem to be getting power into the igniter...not sure what model it is from. I did replace the Coil this week just to eliminate that being the issue. I need to test the grounding next. Appreciate the help!! It was working a few days ago. wondering if something rattled lose.

 

[Curt]

Did you replace your coil with a ballast or non ballast unit? The grey wire coming from the fender apron doesn't look original. There should be a larger diameter black and yellow wire that supplies 12+ volts or possibly 9.6+ volts of your 78 has the built in resister.

http://www.globalsoftware-inc.com/c...ics/FJ40/1978FJ40/1978fj40_wiring_diagram.pdf

 

[Curt]

My 78 right off the wiring harness the thin black yellow wire goes to igniter box 12.5+ volts and the larger black yellow goes to coil + either 12.5+ or 9.6+ volts with the resister wire in harness.

There is also a thin black yellow wire on your starter that supplies full voltage to coil at startup for cold starts. You can try to disconnect to isolate your problem, i never have it connected and still starts at -10*C no problemo.

 

[otbkool]

Thank you. I will try that - I do see it connected. That will be my next step.

 

[otbkool]

I did change the ground. Unfortunately - still nothing. Narrowing it down.

 

[fjc-man]

Maybe try a jumper wire from battery positive to coil to eliminate any gremlins interrupting current flow to the coil while cranking.

 

[otbkool]

Hi @fjc-man - thank you!! That did the trick. She fired right up. I assume that means that the Black and yellow from the ignition that @Curt showed may be the challenge. Any tips on tracing the wiring challenges?

THANK YOU GUYS - Feel great that you have helped me narrow down the issues.

 

[fjc-man]

Kool, I know this question is laughable but do you at least have a guesstimate how many miles are on your 40?

 

[otbkool]

If I go by the odometer <400 My guess is that is when the restoration work was done. There was no additional history I was able to get. There are some things that they did that were short cuts but it gives me something to work on! I am still learning the truck!

 

[fjc-man]

As old as it is, I’m gonna throw a number out there. Let’s say, 125,000 miles. So it’s probably safe to guess the ignition switch has been cycled 40,000 times. The electrical portion of the ignition switch you pictured in post #5 has electrical contacts inside much like the points used in older distributors. They wear and build up resistance to current flow with use over time. This style isn’t really serviceable. This is probably your “gremlin”. I’d replace it, it’s easy.

 

[otbkool]

Ok. @fjc-man i made the wrong assumption that if the direct connect to the battery meant that the unit was working. I realize now that I bypassed it. Do you recommend replacing it with another used Toyota part or is there another manufacturer that has a similar part. There was a blog about a Napa TP50 unit. ....

thanks again!!!

 

[fjc-man]

Check out @cityracer.com list under “ignition”. 32 bucks for your 78.

 

[fjc-man]

Oops, that’s @cityracerllc.com

 

[otbkool]

Done. Thanks again. I’ll keep you
Posted on the progress.

 

[DougAustinTx]

There is a fusible link in the wiring harness going to the coil that sometimes gets weak and needs to be replaced as well.

 

[otbkool]

Thanks @DougAustinTx - I will take a look at that as well - just reading about them now!