1978 FJ40 2F Idles ok, stalls when trying to accelerate unless high revs and other stuff!!

[numby]

Backfiring through the carb is often incorrect timing. All the unused fuel misting about says incorrect timing to me as well.

You need to set the flywheel to the BB - not the line - otherwise you'll be too retarded to run well. Make certain you're not 180º out of time as in one full rotation of the crank (360º). Set Cylinder No. 1 to TDC as best you can by confirming that both valves are closed. Next aim your rotor at the No. 1 contact inside your distributor cap. It doesn't matter which spark plug you're pointing at as you can use any wire as the No. 1 or the distributor can be rotated to any convenient position. It's just conventionally been done with the distributor in a particular position for assembly line consistency. I ran an HEI distributor for years that was rotated about 90º from a "normal" position. I just used a different connection on the cap for the No. 1 wire and pointed the rotor directly at it to get it started and then followed up with a timing light.

Yes, you can choke the carb. Most 2Fs are hard to start without a little choke. Confirm that you're seeing the accelerator pump squirting fuel into the throat by looking down the primary bore and actuating the throttle linkage with your hand - engine off of course.

I don't recognize the procedure you used to check for compatible coil resistance. Going from memory (?) all you need to do is disconnect everything from the coil and check resistance across the two studs. If it's too low add a ballast resistor that brings the total resistance into spec or the Pertronix will fry. If too high you'll need a different coil or the Pertronix will misfire.

 

[cmcmill01]

Backfiring through the carb is often incorrect timing. All the unused fuel misting about says incorrect timing to me as well.

You need to set the flywheel to the BB - not the line - otherwise you'll be too retarded to run well. Make certain you're not 180º out of time as in one full rotation of the crank (360º). Set Cylinder No. 1 to TDC as best you can by confirming that both valves are closed. Next aim your rotor at the No. 1 contact inside your distributor cap. It doesn't matter which spark plug you're pointing at as you can use any wire as the No. 1 or the distributor can be rotated to any convenient position. It's just conventionally been done with the distributor in a particular position for assembly line consistency. I ran an HEI distributor for years that was rotated about 90º from a "normal" position. I just used a different connection on the cap for the No. 1 wire and pointed the rotor directly at it to get it started and then followed up with a timing light.

Yes, you can choke the carb. Most 2Fs are hard to start without a little choke. Confirm that you're seeing the accelerator pump squirting fuel into the throat by looking down the primary bore and actuating the throttle linkage with your hand - engine off of course.

I don't recognize the procedure you used to check for compatible coil resistance. Going from memory (?) all you need to do is disconnect everything from the coil and check resistance across the two studs. If it's too low add a ballast resistor that brings the total resistance into spec or the Pertronix will fry. If too high you'll need a different coil or the Pertronix will misfire.

So set the flywheel to TDC and then used tie wrap to check cyl 1 was at the top which it was.
The rotor is pointing at contact 1 or spark plug position 4, only one way on putting the dist cap on. Also used an in-line spark tester and it is flashing. Anything else to check when I have the FJ40 at TDC all this pushing back and forth is great excerise!!!

 

[cmcmill01]

Some pics

 

[cmcmill01]

Couple of videos, I expected the spark to be more often!!

 

[cmcmill01]

Backfiring through the carb is often incorrect timing. All the unused fuel misting about says incorrect timing to me as well.

You need to set the flywheel to the BB - not the line - otherwise you'll be too retarded to run well. Make certain you're not 180º out of time as in one full rotation of the crank (360º). Set Cylinder No. 1 to TDC as best you can by confirming that both valves are closed. Next aim your rotor at the No. 1 contact inside your distributor cap. It doesn't matter which spark plug you're pointing at as you can use any wire as the No. 1 or the distributor can be rotated to any convenient position. It's just conventionally been done with the distributor in a particular position for assembly line consistency. I ran an HEI distributor for years that was rotated about 90º from a "normal" position. I just used a different connection on the cap for the No. 1 wire and pointed the rotor directly at it to get it started and then followed up with a timing light.

Yes, you can choke the carb. Most 2Fs are hard to start without a little choke. Confirm that you're seeing the accelerator pump squirting fuel into the throat by looking down the primary bore and actuating the throttle linkage with your hand - engine off of course.

I don't recognize the procedure you used to check for compatible coil resistance. Going from memory (?) all you need to do is disconnect everything from the coil and check resistance across the two studs. If it's too low add a ballast resistor that brings the total resistance into spec or the Pertronix will fry. If too high you'll need a different coil or the Pertronix will misfire.

Looks like TDC

 

[numby]

You can tell if you're at TDC on the compression stroke and not the exhaust stroke because the valves won't move until the piston is at BDC again - or thereabouts. You should be able to spin the Int and Exh pushrods with your fingers because they won't be under any pressure from the cam lobes.

My '78 with a Pertronix unit in a Toyota distributor fires up almost instantly. All I need is a couple of pumps on the accelerator pedal and the choke pulled out just past half way (just past the detent). Make certain you have the coil bypass wire connected to the starter or it can be tough to fire when cold. You'll need the extra juice but it's only temporary. It comes off the starter solenoid as a small black wire with a white stripe and - in the factory wiring diagram - turns magically black/yellow and connects directly to the coil positive. Mine was hacked so I just ran a standalone wire rather than try and trace it through the harness. The coil positive is the same place you run the red wire to the Pertronix unit from and where the normal larger black w/ yellow stripe wire also connects. The larger B/Y wire is already resisted (buried in the harness) and is the Ign ON wire. That means there should be three wires at the coil positive post.

If you know you're getting fuel (fuel cut solenoid on carb working - accelerator pump squirting fuel down the throat of the carb) then it's either a spark issue like timing or maybe a weak battery? or it's an oxygen issue as in a badly clogged air filter or crazy timing because you're 180º (360º @ crank). I keep saying the timing thing because of the way your engine sounds on the videos. It reminds me of a time when someone I knew had that issue and it sounded the same. It's been a lot of years so I may be remembering wrongly. Good luck. I'll check back in a week when I get back to town.

 

[cmcmill01]

You can tell if you're at TDC on the compression stroke and not the exhaust stroke because the valves won't move until the piston is at BDC again - or thereabouts. You should be able to spin the Int and Exh pushrods with your fingers because they won't be under any pressure from the cam lobes.

My '78 with a Pertronix unit in a Toyota distributor fires up almost instantly. All I need is a couple of pumps on the accelerator pedal and the choke pulled out just past half way (just past the detent). Make certain you have the coil bypass wire connected to the starter or it can be tough to fire when cold. You'll need the extra juice but it's only temporary. It comes off the starter solenoid as a small black wire with a white stripe and - in the factory wiring diagram - turns magically black/yellow and connects directly to the coil positive. Mine was hacked so I just ran a standalone wire rather than try and trace it through the harness. The coil positive is the same place you run the red wire to the Pertronix unit from and where the normal larger black w/ yellow stripe wire also connects. The larger B/Y wire is already resisted (buried in the harness) and is the Ign ON wire. That means there should be three wires at the coil positive post.

If you know you're getting fuel (fuel cut solenoid on carb working - accelerator pump squirting fuel down the throat of the carb) then it's either a spark issue like timing or maybe a weak (battery?) or it's an oxygen issue as in a badly clogged air filter or crazy timing because you're 180º (360º @ crank). I keep saying the timing thing because the way your engine sounds on the videos. It reminds me of a time when someone I knew had that issue and it sounded the same. It's been a lot of years so I may be remembering wrongly. Good luck. I'll check back in a week when I get back to town.

Okay, cheers. I'll have another look and follow the video below, which I think explains it pretty well.

 

[cmcmill01]

With the continuing saga of trying to fix and do some preventative maintenance, I decided to replace the gaskets around the manifold!!
I think I have managed to strip the bolts going up into the manifold!!!!
Any ideas on how to fix, Helicoil?? Longer bolts, as there is still some thread at the end?

Additionally, as you can see below, the Remflex gasket is significantly thicker than the one that came with it. Maybe why the bolts didn't get a good fix!

 

[65swb45]

IH8Remflex.

 

[numby]

I haven't had any real issues with Remflex gaskets but have only used them a few times. I currently have one on my 40. They do seem soft and like they would distort if your exhaust system is putting any pressure on them during frame twist.

Maybe just pick up a replacement manifold and repair yours later?

 

[cmcmill01]

So Update!!!
So did the Helicoil fix on the manifold, which worked, and I was able to torque up the Remflex gaskets up to 25ft-lbs as per the spec. Refitted everything, including Petronix points and ballast, and also followed the above video on fitting the distributor. I had it fitted a revolution out, but I had missed the mark on the wheel flyby while rocking it back and forth. Only with the cover off was I able to tell!

Tried to start, but the FJ40 was having none of it. However, I could notice something was different from before; it was definitely trying to get going. A couple of more tries until then, I turned the distributor, and she fired straight up.

I then went about tuning it using the timing light, tacho, and a vacuum gauge.

See the video below. I set the timing to 10 BTDC, went for a drive, and it ran very well.


Video of FJ40 running


So conclusion, on why it wasn't running well originally, I think the last bolt on the manifold gasket near the bulkhead was loose (maybe, not 100% but when i went to replace the gasket it was very loose, and dont think i had already lossend it, should have checked this at the very beggining!!), that bolt also had a nut on it, is that correct??? Seems a little strange!

Anyway, I will supply an update if any other issues happen, and any feedback on the video is welcome. Thanks for all the help as well, cheers

 

[numby]

Good work. Now you know what it sounds like when a distributor is timed to the intake/exhaust stroke instead of the compression stroke. That knowledge will come in handy to save one of your buddies whose scratching his head listening to his engine go poketa-squee-poketa-poof-poketa-boing-poketa-bang poketa...