Carb issue after reinstalling (California type) (1 Viewer)

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Sooo... Got my carb back on today (with my broken leg and a friends help) and it is doing something very similar to this racing idle you are experiencing. Upon starting it doesn't do it right away but if i pump the gas a few times the idle races. Marlin rebuilt my carb so I would say a reputable person did the work. What am I missing here?
 
After some further thought and a couple more tries I'm thinking it's not mechanical or the linkage... Vacuum maybe? I'm thinking this because when it starts racing after a few pumps of the pedal, if you turn the key off and on again real quick it immediately settles back down to idle. Turning off the ignition stops the engine from racing. You don't even have to start it again if you catch it before the motor dies and it's right back to normal idle... Give it three pumps and it races. Any ideas? I've gone over the emissions manual over and over and I think/hope i have all the vacuum hoses in the right location. I ordered a few new VTV's as I had a green one where a blue was called for. Other than that what should I try next?

@Mandrew have you had any luck with this? Get it sorted?

@NeverGiveUpYota Felicity, Got any ideas?
 
joebattle1 said:
After some further thought and a couple more tries I'm thinking it's not mechanical or the linkage... Vacuum maybe? I'm thinking this because when it starts racing after a few pumps of the pedal, if you turn the key off and on again real quick it immediately settles back down to idle. Turning off the ignition stops the engine from racing. You don't even have to start it again if you catch it before the motor dies and it's right back to normal idle... Give it three pumps and it races. Any ideas? I've gone over the emissions manual over and over and I think/hope i have all the vacuum hoses in the right location. I ordered a few new VTV's as I had a green one where a blue was called for. Other than that what should I try next?

@Mandrew have you had any luck with this? Get it sorted?

@NeverGiveUpYota Felicity, Got any ideas?
Click to expand...
Like Jim stated above, the VSV can act like a check valve. If you can shut the key off and on and the idle drops, odds are you have something like the AC idle up hooked to the wrong VSV/ vacuum source or the AC idle up VSV is coming on when it shouldn’t. The VSVs are the only electrically controlled vacuum switches.
Try pulling the vacuum line off the AC idle up diaghragm when it’s racing and see if the idle drops. That would help isolate the problem a bit and tell you if something is causing the vacuum to pass to the diaghragm and work backwards from there.
 
joebattle1 said:
After some further thought and a couple more tries I'm thinking it's not mechanical or the linkage... Vacuum maybe? I'm thinking this because when it starts racing after a few pumps of the pedal, if you turn the key off and on again real quick it immediately settles back down to idle. Turning off the ignition stops the engine from racing. You don't even have to start it again if you catch it before the motor dies and it's right back to normal idle... Give it three pumps and it races. Any ideas? I've gone over the emissions manual over and over and I think/hope i have all the vacuum hoses in the right location. I ordered a few new VTV's as I had a green one where a blue was called for. Other than that what should I try next?

@Mandrew have you had any luck with this? Get it sorted?

@NeverGiveUpYota Felicity, Got any ideas?
Click to expand...
Yotr not talker by AC right @joebattle1. Throttle linkage sticking. Polish all the ball and socket pivoting areas. Don’t put lube on tho cuz they collect dust. That would be my thought. Be sure the horizontal spring holder on the throttle return is tensioning the right direction. I think there’s pictures above in this thread. At work now so can’t check.
 
Fixed! She’s purring like a kitty now. It was vacuum. The Emmisions manual is a touch vague on a few connections and I had a few mixed about. It was not the linkage. The key on off was the tell if you will for me.

I’ve got the whole thing buttuned up but I couldn’t test drive it cause my leg is broken. Gotta wait for my friend to come over tomorrow and take me for a ride in it.

@Mandrew sounds like your problem could be similar to mine. Go through the vacuum system again. Let me know if you need any pics of mine.
 
68FA3CCC-5CDB-4B20-9A53-D7484689F1C7.jpeg
I failed smog today. I give up. I’m running rich. Helllp??? The rig is running so good too.
 
joebattle1 said:
bottom HAC filter
Click to expand...
Pretty sure you can’t see into the HAC, it’s an enclosed valve pictured below. So I’m guessing your talking the air cleaner filter. Is it moisture or oil?

image.jpg
 
So then your getting blow by (I believe leaking valve seals). Pull the PCV from the passenger side and see if you have good movement of the ball inside. Could be loaded up w/ crud. You can spray it well w/ brake cleaner (off the truck) and shake it up and down to clear the crud.
But that’s not going to be a make it for the emissions. The other end of the PCV attaches to a hardline. Take the rubber hose from the top of the valve and try blowing into it w/ your mouth. My hardline when I desmogged was fully closed by carbon. I ended up ditching it altogether and adding a block off plate w/ a 90 attached at the intake manifold.
Jim would be best able to direct you since you need to stay smogged. But this is just an observation of signs your finding.
 
Shoot I’m just realizing this isn’t your thread @joebattle1. Maybe move it to a new thread.
 
NeverGiveUpYota said:
Shoot I’m just realizing this isn’t your thread @joebattle1. Maybe move it to a new thread.
Click to expand...

I debated starting one but I figured all Smog info is good in a contained area. Maybe I'm wrong... Apologies for the highjack @Mandrew. If you want me to leave... Say the word.
 
Have you gone through your air injection system? Could be check valves are bad and or smog pump problems.
 
Thanks Jim. I noticed some moisture in the bottom HAC filter. I’ll look through the Emissions Manual on troubleshooting that.
Click to expand...

Yes, The filter on the bottom. Felt like oil actually.
Click to expand...

The HAC valve bottom filter can suck up PS fluid leakage, or just get saturated from oil blowing by in the slipstream.

But a dirty HAC filter is not a cause of rich running. The valve has to fail a specific way and suck fuel out of the carb HAC fitting(s) & into the manifold vac fitting.
 
FJ40Jim said:
The HAC valve bottom filter can suck up PS fluid leakage, or just get saturated from oil blowing by in the slipstream.

But a dirty HAC filter is not a cause of rich running. The valve has to fail a specific way and suck fuel out of the carb HAC fitting(s) & into the manifold vac fitting.
Click to expand...

Thanks Jim. Georg has one laying around so he’s shipping it over to me. Does anyone have a clear pic or can show me how the HAC should be plummed. The manual is vague in the photo for this. It shows 4 flat connections if you will but doesn’t define top or bottom or front/rear.

I’ve never done a valve adjustment. I’ll look into that as well.

One other thing I noticed is I’m running the exact same smog numbers as before the carb went to Marlin for rebuild.
When adjusting the fuel air mix... How do I know when ive got it right? Does this have to be done on the smog dyno?
 
You need to get the emissions FSM. It clearly shows where the vac hoses are routed for every emissions component. It also tells how to adjust idle mix for best emissions performance.

There are links on this forum to download a PDF of the emission FSM.
 
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