Frustrating

[shawnfj40]

I thought that as well. When I rebuilt the carb I did the carb dip and cleaned everything very well used carb cleaner to make sure nothing was plugged. I looked in the carb and when it's idle I can see fuel from the main jet streaming in and give it a little gas and you can see fuel from the accelerator pump streaming in. When it first started issues I checked timing and it was far advanced to where you couldn't see the bb in the window at all. I'm thinking I may need to pull the timing cover and make sure it's not off a tooth

These motors don't get off a tooth.

 

[shawnfj40]

It sounds to me like you have your firing order mixed up. Check that out i.e.. "no power and backfiring"

 

[jstairwalt]

Well your definately getting idle fuel. I've read where guys snip of the end of the IS. But if you can see the booster nozzle participating in idle fuel delivery, it might be worth figuring out. If your idle cucuit's not clogged, is your idle speed screw holding your primary throttle plate too far open. Perhaps back off that screw and advance your timing some and see. Maybe that will pull idle fuel from the right location.

I don't think you would regret switching to Pertronix. Perhaps try that before you go Weber. As you know spark is very critical and I like the fact I don't have to tinker with my points. Or wonder if they are dialed in. But they will be in my glovebox as a spare.

Fuel level in your sight glass good?


Have you checked your valve lash?

The fuel level in my sight glass is just a tiny bit above half. And it does look like it has been snipped off. Any ideas why people would snip them off. I will check the dwell and try advancing the timing and backing off the throttle screw. If the vsv is not working can I eliminate it and if so what do I do with the emissions line from the charcoal canister. I wouldn't mind eliminating all the emissions stuff and get rid of the vapor thing in the back of the middle seat

 

[Hack]

Can we all assume that when you replaced the distributor parts, you checked the position of the rotor with regards to TDC (compression) on Number 1? And all the wires are in the correct order?

Firing Order: 1, 5, 3, 6, 2, 4
Ignition timing/idle speed – 7deg. BTDC / 650 rpm

 

[jstairwalt]

Can we all assume that when you replaced the distributor parts, you checked the position of the rotor with regards to TDC (compression) on Number 1? And all the wires are in the correct order?

Firing Order: 1, 5, 3, 6, 2, 4
Ignition timing/idle speed – 7deg. BTDC / 650 rpm

Yes I made sure the rotor was pointing at the number one spot on the cap and the firing order is correct it is timed to the bb at 650 rpm. It's runs perfect until I drive it when it's a load the weight of the vehicle is when it does the backfire from the carb and lacks power

 

[Hack]

How's the mating surface where the carb bolts to the manifold? Possible leaks? Could do a propane test, but since it only occurs under load, that won't be practical.

 

[jstairwalt]

I will bet dollars to donuts your dwell is way below spec at that setting. Don't be surprised if your vacuum improves with the hotter spark as well.

Best

Mark

www.marksoffroad.net

It's looking like you are correct I'm pretty sure the bushings in the dizzy are worn and I'm getting to much play in the shaft. When it's running I can move it back and forth enough to where one direction it's right at 40 degrees and the other way it's like 20 degrees

 

[Trollhole]

Bad dizzy

 

[jstairwalt]

Bad dizzy

Yes I do believe the dizzy is bad. Any ideas where I can get a good one for a reasonable price. The local parts house can get me a rebuilt one for 103

 

[GHalll]

Yes I do believe the dizzy is bad. Any ideas where I can get a good one for a reasonable price. The local parts house can get me a rebuilt one for 103

@Trollhole can get you a good electric Dizzy..

^

 

[sggoat]

I will check the dwell and if it's way off should I set it to dwell specs?

Dwell will not help if your points are not gapped correctly--in fact dwell is NOT the best indicator--your point gap IS. Did you replace the points with OEM? If not, you may be experiencing decreased point gap due to a worn phenolic piece that rubs against the dizzy lobes--it will slowly wear away, causing timing issues just as you have described--check the point gap--see if it has changed--

 

[sggoat]

Bad dizzy

Need some info here to help my learning about these trucks--
If the dizzy shaft(or bushings) are worn causing the shaft to "wobble", I would think that the engine would idle very poorly(as it is not under any appreciable load, and just kind of 'floating')? When the engine is loaded(increased RPMs), seems like the shaft would "walk" to a quadrant in it's rotation and stay there(wherever "there" is)-simply due to centripetal force-might be advanced, or retarded, but seems it would stay there until the engine load changed. Does this make any sense?

 

[thebigredrocker]

I've seen a number of engine photo's with D.U.I dizzy's. Guessing they are decent.

Sticking with OEM is usually a safe move. Seem's like OEM dizzy's are in FJ40Jim's wheel house if you want a better than when new Nippondenso.

It is true.
There is not a thread to explain this.

For more info, write your name & address on a $100 bill, tape it to the dissy, mail the dissy to me and it will be fixed.

 

[Trollhole]

Need some info here to help my learning about these trucks--
If the dizzy shaft(or bushings) are worn causing the shaft to "wobble", I would think that the engine would idle very poorly(as it is not under any appreciable load, and just kind of 'floating')? When the engine is loaded(increased RPMs), seems like the shaft would "walk" to a quadrant in it's rotation and stay there(wherever "there" is)-simply due to centripetal force-might be advanced, or retarded, but seems it would stay there until the engine load changed. Does this make any sense?

It doesn't work that way because of the type of shaft the oil pump uses. Makes it walk really side to side. Plus the counter weights come on at different RPMS. Thus it is really unpredictable as to what it will do.

 

[65swb45]

Dwell will not help if your points are not gapped correctly--in fact dwell is NOT the best indicator--your point gap IS. Did you replace the points with OEM? If not, you may be experiencing decreased point gap due to a worn phenolic piece that rubs against the dizzy lobes--it will slowly wear away, causing timing issues just as you have described--check the point gap--see if it has changed--

For the most part I do not consider it my job to correct all the misinformation on the Internet. But every once in a while I am moved to do more than just bite my cheek.

Please share the source of your statement Gary.

The strength of the spark is fundamentally a product of how long the coil can buildup voltage before a break in the circuitry causes the voltage to discharge into the main spark lead. The longer the duration, the hotter the spark. This length of time is measured in degrees and is called dwell.

 

[jstairwalt]

It doesn't work that way because of the type of shaft the oil pump uses. Makes it walk really side to side. Plus the counter weights come on at different RPMS. Thus it is really unpredictable as to what it will do.

I don't consider myself a mechanic I have been tearing things apart and fixing them my whole life. When I rebuilt the carb I used pin heads videos on YouTube as a guide and all looked up the specs for the carb. I could tell that the carb had been taken apart before probably several times. The idle solenoid rod has been snipped off. And the spring for the accelerator pump was 3 little springs all pulled on top of each other I have several other springs for that that I have changed and not sure if I'm using the correct one but the one I found to work best is fairly stiff. As far as the dizzy I could tell it has been taken apart a few times had some stripped screws on it. I did fix everything that has been abused on it but there is definitely play in the shaft and the springs for the mechanical advance don't match. At this point I am thinking I'm gonna get the rebuilt dizzy for 100 bucks from oreily to see if that will work. I'm not sure what else to try

 

[jstairwalt]

For the most part I do not consider it my job to correct all the misinformation on the Internet. But every once in a while I am moved to do more than just bite my cheek.

Please share the source of your statement Gary.

The strength of the spark is fundamentally a product of how long the coil can buildup voltage before a break in the circuitry causes the voltage to discharge into the main spark lead. The longer the duration, the hotter the spark. This length of time is measured in degrees and is called dwell.

So when I set my points gap to 0.018 and the dwell reading is way off unless I pull up on the front (diaphragm side) of it and it will read 38 degrees but when I let it go it goes back down to about 20 would you say that the play in the dizzy shaft is a problem

 

[emac]

On my rig, I had an aftermarket carb and dizzy. I bought Trollholes electronic dizzy and carb and they have worked out pretty well. I dont know your time/money situation but T-holes products are pretty well proven to work. It may be something to consider, especially if you have doubts about your carb rebuild.

 

[jstairwalt]

On my rig, I had an aftermarket carb and dizzy. I bought Trollholes electronic dizzy and carb and they have worked out pretty well. I dont know your time/money situation but T-holes products are pretty well proven to work. It may be something to consider, especially if you have doubts about your carb rebuild.

I have heard nothing but good about trollholl. I am definitely interested in getting a carb and dizzy

 

[stevebradford]

Spark plug wires on the right cylinders, two could be crossed? Sounds dumb but it happens...