1975 FJ40 2F carberator issues. Aisan

[Kuzemkafj40]

Hello
New guy here.
I have a newly rebuilt 2F. Newly rebuilt carb. Its the original Aisan. It was dipped and very carefully reassembled. The fuel level is at half glass. The engine will start and idle perfectly. If I give it a little throttle, by hand while looking at the carb, it will immediately die. If im careful, I can slowly throttle up and it will increase rpms as you would expect. When I do a quick throttle and it dies, sometimes, most of the time , ill get a back blast up and out of the carb. I will say, I dont get the accelerator pump squirt every time. The pump is new. I put a second accelerator pump in and same thing happens.
The valves were adjusted cold at .003" over spec.The distributor is a Performance Distributors D.U.I.
Also, I can actuator the accelerator pump by hand when the engine is off and fuel at half glass and I get a sporadic stream and sometimes none. Thanks for any advice.

 

[Pighead]

When I do a quick throttle and it dies, sometimes, most of the time , ill get a back blast up and out of the carb.

What is your timing set at?

 

[Kuzemkafj40]

What is your timing set at?

Thats a great question. I dont have a scale on the bell housing to show degrees. The timing is adjusted to the indicator as it lines up exactly to the flywheel mark. I dont have a scale for adjusting to BTDC

 

[charliemeyer007]

Well I think your accelerator isn't working correctly. Did you wire and blow out all the passages after the dip? Second is how well the pump cup seals. I don't do Aisan but leather and plastic cups can take a set from being in the parts pact. I would press the lip out on a warm flat surface so it will seal in the bore.

 

[Kuzemkafj40]

Well I think your accelerator isn't working correctly. Did you wire and blow out all the passages after the dip? Second is how well the pump cup seals. I don't do Aisan but leather and plastic cups can take a set from being in the parts pact. I would press the lip out on a warm flat surface so it will seal in the bore.

Thanks...I will try that cup adjustment.

 

[Pighead]

The timing is adjusted to the indicator as it lines up exactly to the flywheel mark.

Which flywheel mark? The line is TDC, the BB is 7*BTDC.

 

[ceylonfj40nut]

Pic of your carb please without air cleaner on. Do you have your power piston port hooked up to manifold vac?

 

[ceylonfj40nut]

Did you do your own rebuild? Follow steps in this video? Especially checking for clear ports after rebuild with led flash light? This is a great reference.

 

[Kuzemkafj40]

Which flywheel mark? The line is TDC, the BB is 7*BTDC.

View attachment 4035576

After I was asked about my timing, I remembered there was some questions in my mind. I did some more reading and with the help of everyone on here....I checked the timing and found that I was way off. I timed it to the BB and made a huge difference. I still have accelerator pump issues but....one problem at a time. Thanks for your help.

 

[Kuzemkafj40]

Pic of your carb please without air cleaner on. Do you have your power piston port hooked up to manifold vac?

 

[Kuzemkafj40]

What is your timing set at?

Its timed correctly now at degrees btdc

 

[Kuzemkafj40]

Well I think your accelerator isn't working correctly. Did you wire and blow out all the passages after the dip? Second is how well the pump cup seals. I don't do Aisan but leather and plastic cups can take a set from being in the parts pact. I would press the lip out on a warm flat surface so it will seal in the bore.

Its timed correctly now at degrees btdc

7 degrees

 

[charliemeyer007]

For a dipped carb it doesn't look very clean. Either the dip was wore out, not in it long enough or some other issue IMHO.

 

[Kuzemkafj40]

For a dipped carb it doesn't look very clean. Either the dip was wore out, not in it long enough or some other issue IMHO.

I would agree that it looks questionable. The dip was brand new and we timed it as per instructions. The FJ40 sat for 15 years under a carport. I watched as a seasoned mechanic of 35 years rebuilt this carb. I know mistakes can happen. The insides of the carb look better than the outsides.

 

[ceylonfj40nut]

Power piston is not connected to manifold vacuum.

 

[ceylonfj40nut]

If it idles perfectly, means your idle circuit is clean. Way fueling works is idle circuit when idle, hit the throttle and the accelletor pump squirt gives extra fuel to transition into higher rpm for vacuum to increase to open up power piston circuit, then lastly secondary jets.

 

[charliemeyer007]

First rule to learn these days is "Just cause its new doesn't mean its good" and that goes for both parts and services these days.

I still think you got gunk in the passages or the accelerator piston cup is fitting correctly, deformed/wrong size....

Good your timing is corrected - it will start and run better. I like more advance than that.

Back in the day I learned from the aviation people "they don't fly any worse clean - inside and out. So your 35 year experience guy should know that the quality of his work is reflected in the total job. Looks like crap on the outside.... And yes big difference between making do on a trail repair vs. sitting inside a nice, warm, dry, well lighted place with a parts store just down the street.

Learn to do the work yourself - no one cares more about your rig than you.

 

[ceylonfj40nut]

^^^^ this. Try connecting your power piston first. If still sluggish, follow Martin Crawler’s video I attached. Be anal about it!

 

[Kuzemkafj40]

Power piston is not connected to manifold vacuum.

View attachment 4035850

If you have time, could you elaborate a little?
What is that for and what are the symptoms of it not being connected?
Thank you

 

[ceylonfj40nut]

Try connecting these two