Ignition Problem Maybe (1 Viewer)

[teamdonzi]

OK, so just had motor rebuilt by reputable shop. 1984 FJ60, now .30 over, stock cam, new everything internally except crank was polished. Everything was installed by them except I installed the carb and connected up the remaining desmogged lines and the air box. Ran fine before, just had low comp in #3 and burned oil and gas like crazy. Had a hell of a time getting new motor started, finally moved the dizzy up two teeth to the right clockwise and it started, ran rough but got it up to 2500 for 20 min in order to do the break in. As soon as I dropped RPM below 2000 it want down to zero like a rock, had to pump pedal to get it going again. For now assuming new cam and crank are installed correctly, so chasing anything else before I tow back to my builder. I did put the dizzy back a tooth to where it should be per manual, as I want this right, not just barely running at 2500, but all correct. I found an issue with ohm check from FSM Fig 8-16 and 8-17. First primary side was 1.4 which is too high and the secondary doesn't give me anything at all. I switched coils but no diff. I do have spark through coil but thinking it is not enough and or out of sync. I swapped coil but same issue. My guess is the Igniter somehow got fried in the process but it did pass the two 12 volt checks in Fig 8-12 and 8-13. The dizzy is for sure at TDC and for sure it is on the power stroke and correct to how it should be with rotor pointing at correct angle to No 1 wire. So again, thinking Igniter, or maybe fusible link, or maybe the signal rotor in the dizzy. Any help would be appreciated before I point finger to building making rookie mistake of not getting timing gears installed correctly.

 

[Mace]

As a general rule, ignitions either work or they don't. It's not a part time thing..

Have you hooked a timing light up to see what your timing is actually set to?

Are you sure the wires are positioned correctly?

 

[teamdonzi]

Ya, so another test shows great spark to the dissy, no spark to the plugs. So something with the dissy or the wire connecting from the igniter to the dissy or ya, I guess could the the igniter (if with a bad igniter you can still have spark from the coil). At least I am narrowing this down, just extremely frustrating to have an ignition problem while trying to get a brand new rebuild cranked over, why would it die now. OK, I need a beer.

 

[Mace]

not the ignitior.. cap and rotor possibly or plug wires..

 

[teamdonzi]

I actually had an igniter go out on me a year or so ago, my fault as I grounded the coil wire ,which I think can kill the igniter. Anyway, when that died I had no spark out of the coil, so based on that anyway, think my igniter is good, so either wire to or the dissy.

 

[teamdonzi]

In terms of cap and rotor, I did switch those to new. I kept the old ones initially, then switched to new cap and rotor with no change to my problem. I also put volt meter on the plug wires, they show 6'ish ohms of resistance and the FSM says under 15 is good. I do have new ones that I can try but not looking likely. So I have an email into JimC regarding this issue and possible troubleshooting. It is a dissy that he recurved a year or so ago, so not sure, but might need to pull it and bench test it. The only other thing I was pondering is, could the spark plug actual spark be so small that I can't see it. I didn't see a spark but it was still light outside, so maybe I try that again at night just to be 100% sure.

 

[cwwfj60]

sounds like your carb fuel cut solenoid is disconnected or lost power....

This is the only wire running to your carb, needs keyed on 12v

 

[Mace]

Do you have a timing light?

That can let you know if you have spark.

 

[Output Shaft]

< inline ignition spark checker, spark plug checker, spark plug test light >

 

[teamdonzi]

Fuel Cut Switch on the carb was checked, I disconnected the wire with key on and heard it click, so I believe that means it is working. Not fully scientific, but think it is working and plugs seem to be getting wet with fuel and when cranking over without a plug, seeing what looks to be fuel blowing out. So think we are good on fuel, air, timing and thus are down to spark. I do have a timing light, so without it running you are saying put it on while cranking it over and it should flash if any spark goes through the spark plug wire. Good idea, we had been doing that but will do that again, as opposed to looking for that little spark plug spark. Now, that all being said, if I have good spark from coil to dizzy, good igniter and no spark to the plug wire at all, what do we think it could be. Are we then down to some internal component of the dissy?

 

[Mace]

If the coil is giving spark, you only have the cap, rotor and plug wires that can be stopping the spark from getting to the plugs. Internal parts of the dizzy just spin and tell the coil to spark..


Assuming it's timed correctly.

 

[cwwfj60]

@Output Shaft has the right idea, it's idiot proof, just get one, they are cheap and fit in the glove box or tool kit. Great thing to keep on hand.

That being said, how did you confirm you have spark at the Coil > Dizzy?

 

[teamdonzi]

Idiot proof......are you mocking me.....LOL

OK, so that is actually good info and good news. So I have spark from the coil wire, I held it with shielded pliers near a ground bolt and have big spark coming out when we turn it over. If I disconnect the igniter to dissy wire, no spark, when that wire is connected I have good spark to coil wire. So what if, I am 180 off, then no spark to the plugs right? So let me go pull on that thread again. I think to best do that I need to go buy that big 1 13/16 socket to turn the crank to help ensure I can bring up #1 piston slowly to TDC on the compression stroke and just make 100% sure I am not 180 off. That was bugging me last night, I am now 95% sure I am not, but lets be 100% sure so I will do that tomorrow and report back. I will freaking poke myself in the eye if that is what this is.

 

[Mace]

You will still have spark if you are 180 out.

It'll just be on the exhaust stroke..
And generally backfires out of the carb.

 

[Output Shaft]

You only need a 6pt socket that fits the power steering pulley nut. It's a 17 or 19mm. Can't remember. Remove all sp plugs, tranny in neutral, tighten the belt a little at the alt. Crank is easy to turn. Remember to loosen the belt to correct tension when done.

You'll be able to see the TDC scribe line up when turning from the ps nut.

 

[teamdonzi]

Great tip. I put a timing light on and did get the flashy light and did not see the 7 degree ball in the window, so gonna work that tomorrow. Hoping I am out 180 off and that will be an easy fix. The other idea is massive vacuum leak on the new header side, but I looked and it looks pretty good. I'll report back. Thanks for the additional threads to pull.

 

[teamdonzi]

OK, new twist today. JimC said check for vacuum leak and I found some suspects. Bottom of carb was hitting a bolt washer and thus not sitting flush on the manifold. And two carb nuts were loose so I fixed that. Also my manifold bolts were not torqued down by my builder, so I put 36-40 lbs on all of those. I also turned the rotor 180 degrees and got it back to TDC/7 degrees with the timing light. So when turning it over, the light flashes hooked to #1 when on the 7 degree ball is seen in the window, but it still wont start. Does the fact that I am flashing on that ball ensure that I am on the power stroke? I would think so but I could spin it 180 again to try that. My neighbor is coming over so we can turn the power steering pump and try to feel for the blow or suck from the #1 spark plug hole to validate we are on the compression stroke. Only other thing is trying to spray some starting spray into the carb to see if that does anything, under the fuel air spark package. Oh, and the fuel in the bowl is at the upper limit in the window, not to the top but at the top of the range so should be fine.

 

[teamdonzi]

OK, put the rotor back 180 and we have lift off, so it seems to have been the big vac leaks on the carb and the manifolds. All good now, working to fine tune advance, timing and carb settings on the new rebuild. Thanks for all the help.