74 fj40 low throttle response and running rough (1 Viewer)

[45Dougal]

No idea but I'd be surprised if it had deteriorated so badly in such a short time, if at all.
Soft lines on the other hand can shed fragments - worth replacing them all if you haven't recently

 

[nitroid13]

No idea but I'd be surprised if it had deteriorated so badly in such a short time, if at all.
Soft lines on the other hand can shed fragments - worth replacing them all if you haven't recently

I can agree there, I need to re run all the hard lines too. This time I'll get ethanol rated line as well for the soft bits. Also to put in return lines as well

 

[nitroid13]

Ok I found some things, I put a in line fpr and set it to 2 psi and no change really. However when I pulled the carb off, the gaskets are wet with raw fuel and there is raw fuel in the intake. I know even after running it, it should be dry in there. Which leads me to believe it's running REALLY rich. I'm in the process of cleaning the carb now. Was just something I found interesting

 

[nitroid13]

Some more things I found was the idle up screw on the linkage was WAY too far in and was basically holding the throttle open. So that is probably why the idle screw had no effect. That would probably also cause it to run rich in turn. Now I do know if I drop the idle it won't run and won't start. Therfore it's not idling at all and it's only really running because you are "holding the peddle down".

Now something I did notice was the float was not level with the top of the carb. And I know from other types of carbs this needs to be level

I'm going to clean it tomorrow and see if it improves. I know i need to pay paticular attention to the idle circuits. Now the jets in the bottom of the bowl should the secondary jet be sticking out that far?

 

[45Dougal]

Ok I found some things, I put a in line fpr and set it to 2 psi and no change really. However when I pulled the carb off, the gaskets are wet with raw fuel and there is raw fuel in the intake. I know even after running it, it should be dry in there. Which leads me to believe it's running REALLY rich. I'm in the process of cleaning the carb now. Was just something I found interesting

View attachment 3388007View attachment 3388012

Looks like it's flooding.
How does the needle valve & seat look if you pull the float out?

 

[pb4ugo]

If the idle mixture screws are ineffective, then it's pulling fuel from somewhere else.

When your checking/setting timing are disconnecting and capping the vacuum line?

 

[nitroid13]

Looks like it's flooding.
How does the needle valve & seat look if you pull the float out?

It looks good and will seal to pressure with just gravity, if you blow through the fuel inlet

 

[nitroid13]

If the idle mixture screws are ineffective, then it's pulling fuel from somewhere else.

When your checking/setting timing are disconnecting and capping the vacuum line?

Yes

 

[nitroid13]

I made sure the float was level and this is where the fuel level is at currently

 

[nitroid13]

Just did a full vavle adjustment and some were too lose and some were a bit on the tight side but all had some movement so that's good and now they are set right. But it's still sputtering and running really rough and especially under load it backfires a bit as well.

 

[45Dougal]

Are you still getting a puddle of fuel in the manifold?
Maybe that was a one off thing when you disassembled it??

Have you checked your spark plugs yet? Good strong blue spark?

 

[nitroid13]

Are you still getting a puddle of fuel in the manifold?
Maybe that was a one off thing when you disassembled it??

Have you checked your spark plugs yet? Good strong blue spark?

It could have been a one off thing tbh, however I have seen it do it before in the past even when it was running ok. And I have looked at the plugs, and I gapped them, they did have alot of black soot on them so I cleaned them. the spark is definitely not blue, but the coil cap rotor and wires are all new. If this is an ignition issue, could it be the igniter box on the coil? If so I know its kinda difficult to test if it has failed

 

[45Dougal]

If its a weak yellow spark then that's probably the first thing to fix.
That would explain why timing it 30 degrees off the mark makes it run better - your spark isn't being blown out by the compression.

Try refitting your old coil?

 

[nitroid13]

If its a weak yellow spark then that's probably the first thing to fix.
That would explain why timing it 30 degrees off the mark makes it run better - your spark isn't being blown out by the compression.

Try refitting your old coil?

One other thing speaking of the coil is mine hooked up right?

Remember this is an 83 fj60 coil setup.

I also have a 80 fj40 one but it'd different and has more wires.

 

[nitroid13]

If its a weak yellow spark then that's probably the first thing to fix.
That would explain why timing it 30 degrees off the mark makes it run better - your spark isn't being blown out by the compression.

Try refitting your old coil?

Now I got the spark bright blue now and I think it may have been a grounding issue. So I got the coil a good ground directly to the battery.

 

[nitroid13]

I made sure the float was level and this is where the fuel level is at currently

View attachment 3388651

View attachment 3388652

Since I did this, I think the fuel level is too low and the accelerator pump in the carb is not getting enough fuel and won't pump now so I got to readjust it

 

[nitroid13]

Made this video to show sound and a few other neat things lol, but I swaped my fj60 dizzy for a hei unit from a 235 chevy i6. But the issues are the same and persistent regardless of ignition set up. So the only thing I can think of at this point is I have a bad intake/exhaust gasket and or bad carb gaskets. I also miss spoke about the vacuum lol and it's less than it's been being