Carb Tuning /ignition question 78 2F ignitor (1 Viewer)

[Ambrew]

Hi All,

I've been reading multiple threads about carb tuning and ignitors for the past few days and would like a bit of help. Engine idles but misses, black/brown smoke at idle and under hard accel. I did leave the ignition on once, and the coil got warm, but if I understand correctly with the ignitor it's not an issue... Here's the deal:

Re sealed bottom end
rebuilt head, new HG
New plugs, wires, cap, rotor, manif gasket
New exhaust valves, valve seals
Head planed
Valves adjusted
new 3mm vac hoses
PCV cleaned and jiggles freely
pulls 13 in/hg at rough idle
idle mix screw has no effect
No detectable vacuum leaks, choke/stall method and carb cleaner method confirm no vac leaks
Timing is on the bb, 7 deg TDC

So I was trying to adjust the carb,(using this method: Carb Works Great! ) and really no effect on Idle. If i unscrew the idle mix at all, vacuum drops. It then dawned on me that the "miss'' and unburnt fuel may be caused by poor spark

Coil resistance test ok.
Engine ground is good
Coil/ignitor bracket ground is good
12+V to coil
Coil polarity properly hooked up: + from batt to + coil, - coil to igniter unit

Therefore I ran the igniter test from the FSM below, and it failed. question is:

• can the igniter fail the test and the truck still run ok, but smokey?
• Is this the correct test for a 78 FJ45? I do not have the resistor as in the diagram, so power was measured going into the coil.
• Is there a secondary test for the igniter i can run?
• Is this all a carb issue?
• Is there a known ''Factory setting'' for the idle speed screw? ie: 4 turns out from bottommed out?

I know the carb needs adjustment, and a possible rebuild, but the truck ran way better before the refresh of the engine with the same carb, at the same altitude. Regardless a carb kit from Bryce at Cruiser Outfitters is on the way.

 

[FJ40Jim]

What kind of vehicle, where was it sold new?

 

[FJ40Jim]

The FSM shows testing a points ignitor for 1975 USA 2F.
The picture looks like a 1978 solid state ignitor.

2 different things.

 

[Ambrew]

It's a Canadian FJ45, 78.... I had a feeling it was the wrong test...

 

[FJ40Jim]

The ignition is fine. If ignition is weak, it will break down under load, but idle OK.

Sounds like the idle is slobbery rich, based on the low vac and black smoke. Either the secondary barrel is cracked open a hair, or the bowl level is too high.

A normal idle mix screw setting is 3-4 turns out.

 

[Ambrew]

Bowl level is smack in the middle. I will check the secondary and report.

 

[Ambrew]

Alright. Got some time in tonight, removed the carb, did a dummy check for cracked manifold, ensured insulator was in correct orientation, checked solenoid function/power, sprayed a can of carb cleaner through it and put it back together. Funny thing, there was no spark when I tried to start it. Took coil and igniter off, re checked, cleaned grounds again and spark is back. Did not have time to adjust so that will have to be tomorrow. BUT, i got a pic of the bowl level: it seems a little high. there was also some crud that may have had the secondary slightly open. Still seems to run rich.

I will search bowl float adjustment, or am I better to leave this until i rebuild the carb?

Also, what is the easiest/cheapest way to take RPM? I don't have a tach so will have to get one. Timing I have light is basic and doesn't do rpm.

 

[Dizzy]

Bad EGR?

 

[Ambrew]

This is a Canadian truck, so only a pcv valve, and it's good...

 

[FJ40Jim]

Bowl level is acceptable.

Get a cheap digital tacho/volt/dwell meter from Princess auto.

 

[Ambrew]

I went and got a tach Multimeter from PA, Unfortunately it does not pick up rpm reliably under 800 or so. Using the red wire to the dizzy, and as it smooths out at around 1200 it seems to become accurate. Perhaps a better quality tool? Or is my pickup not functioning correctly? I checked the gap and it's within spec (0.008 to 0.016)

Re adjusted the valves, and if I have the idle mix all the way in it idles without smoke, albeit missing once in a while. Smokes heavily when revving the engine. Driving to the store it missed 3 or 4 times and then ran like a champ. by the time i got home black smoke again, but not as bad as before.

Secondary seems to stay closed at idle, sprayed carb cleaner and it pools on top.

I guess the next step is to wait for the carb rebuild kit? Or should i be able to get it running better before adding variables?

So how does a guy from Ohio know about PA? Travel much?

 

[DougAustinTx]

Intermittent loss of power sounds like either fuel or ignition. Switching out parts is the sure way to narrow down the problem.
Your vacuum is lower than normal at 13. It should be closer to 20. Make sure your brake booster is holding vacuum (suck on the hose and see if you can pull a vacuum).
In regard to the loss of power while driving, you can monitor the voltage at the coil under load. Run a wire from the + terminal on the coil into the cab and connect to your meter. Ground the negative of the meter to complete the circuit. Sometimes a circuit will have correct voltage, but insufficient current to get the job done.....usually caused by a bad connection (possibly in the electrical contacts of the ignition switch.) If the connection is bad enough under load, it will begin to pull the voltage down.

 

[FJ40Jim]

If the idle mix screw is turned in all the way, then there is way too much fuel coming in somewhere else. Most likely is through the second barrel idle circuit. When the carb is off post some pics of the bottom of the carb so we can see how the throttle plates are situated.

I know PA and CT because I'm a car guy who's been to Canucistan a few times. It's just across the pond from us, dontcha know.

 

[Ambrew]

Doug,
I suspected the ground of the coil/igniter to be faulty so I tried with a jumper, no difference. I have a new coil on the way from rockauto so I will try that this week. On the bench, the coil ohm test seems within spec, but on truck, it varies. Makes no sense I know, connections have been cleaned several times.

Yes vacuum is low. I am using the BBooster hose as the source for vacuum. I have replaced all the small hoses and trimmed the rough ends of the larger diameter ones. They seem in good enough shape otherwise. Seems to me if there was a vacuum leak it would cause a lean condition vs a rich one? Right now i have to screw the idle mix in all the way to get it to run decently.

I replaces the ignition switch (oem) to re-key the cruiser, it came with different keys for the doors. Connection seemed clean and in good condition. I've also replaced the fuses so those connections got looked at. Even checked the engine ground since it was out. See here:2F compression numbers - how deep to go into engine?

Jim, I'll take it off and post pics. Can't say I know much about Ohio other than having spent a couple weeks in Columbus years back. Pleasantly surprised how nice it was! that and a couple runs accross I64.

 

[Ambrew]

In case Captain obvious is around and i'm missing something, here's a few pics:

As it was on the truck:

block orientation:

As it came off the truck:

After some jiggling:

So: Sticking secondary is a probable cause? I'm going to go look at servicing it without taking the carb apart....

When I drove it yesterday, it was running great when i left the house and poorly when i came back. Also, rpm's would sometimes stay high despite nothing on the accelerator pedal. So I'm thinking this would be copacetic with a sticking secondary... do you concur Dr?

 

[FJ40Jim]

Yes, sticking secondary.

Disconnect the rod from the secondary diaphragm, then move the secondary throttle. It should move easily through 90* of travel.
This is not what will be found. It will be draggy & sticky. Soak the ends of the shaft w/ PBblaster, twist the shaft to& fro, also move the shaft axially in the bore with the throttle open (there is no axial play w/ throttle closed). This is an attempt to break up the varnish & rust that has glued the shaft into the throttle body.

 

[Ambrew]

Wasnt that bad. I guess maybe just enough to cause a headache. we'll see tomorrow when I run it again.

 

[FJ40Jim]

If you were 'Murikan, I'd tell you to use a .32 cal pistol brush to clean out the bore in the T-body.

Make sure the throttle blade is oriented correctly upon reassembly.

 

[Ambrew]

Well... I did use a brush, just not a .32 one specifically...... Voila!!! after adjustment, 19 inch at 650rpm. Happy with that. Thanks for the help! Let me know if ever you're in Ottawa. Test drive tomorrow.