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| Slant six running rough/lean and not performing right. SOLVED!! https://slantsix.org/forum/viewtopic.php?t=63294 |
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| Author: | JukkaK [ Thu Feb 14, 2019 9:14 pm ] |
| Post subject: | Re: Slant six running rough/lean and not performing right. |
Quote: 1966 carb with pcv tube on drivers side of carb ?? early manifold had extra hole and gasket to line up to pvc port. Later manifold, pcv on passenger side of carb, did not have extra hole. Need to notch gasket if using late manifold, see if pcv has strong vacuum. https://www.slantsix.org/forum/viewtopi ... ole#p55239
It has the PCV port in the driver side of the carb and there is a strong vacuum all the time, enough to kill the engine right away if I pull the hose off.I also tested to drive it with that port plugged, didn't do any good. I'll take the carb out of the car tomorrow and check the float level and condition, while in there I'll check the jet size and install the size 58 into it if it is anything smaller than that. I adjusted the accelerator pump linkage so that it squirts all the fuel faster, it helped a little with the stumbling when accelerating so it kinda tells me that it doesn't get enough fuel overall.
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| Author: | matv91 [ Fri Feb 15, 2019 3:15 am ] |
| Post subject: | Re: Slant six running rough/lean and not performing right. |
Looking down into carb from front, on left there is a paper clip size hole. That is idle air bleed hole. May be too big. https://www.slantsix.org/forum/viewtopi ... re#p439992 |
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| Author: | matv91 [ Fri Feb 15, 2019 3:19 am ] |
| Post subject: | Re: Slant six running rough/lean and not performing right. |
https://www.slantsix.org/forum/viewtopi ... bleed+wire |
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| Author: | JukkaK [ Fri Feb 15, 2019 8:55 am ] |
| Post subject: | Re: Slant six running rough/lean and not performing right. |
I got the size 58 jet from the parts store, took out the old one only to discover that it was a size 58 already. I roughly checked the float level while in there although I'm going to take the carb off the car tomorrow and set it to spec properly. In some "Mikes carburetors" video he mentions that basically if the float is horizontal you're about ok, mine was clearly lower. I adjusted it a very tiny bit higher than it was and noticed that it actually got a bit better but there still is the light throttle miss when cruising down he road and stumble if I punch the pedal to the floor fast. Could the float level really be that critical? |
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| Author: | JukkaK [ Fri Feb 15, 2019 9:10 am ] |
| Post subject: | Re: Slant six running rough/lean and not performing right. |
Quote: Looking down into carb from front, on left there is a paper clip size hole. That is idle air bleed hole. May be too big. https://www.slantsix.org/forum/viewtopi ... re#p439992
I'll also test to restrict that airbleed and se if it helps.
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| Author: | matv91 [ Fri Feb 15, 2019 6:23 pm ] |
| Post subject: | Re: Slant six running rough/lean and not performing right. |
Could the float level really be that critical? Simple answer yes, the wet fuel level in bowl if too low- too lean and flow in venturi starts too late. If too high - rich, flow starts early. |
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| Author: | matv91 [ Fri Feb 15, 2019 6:31 pm ] |
| Post subject: | Re: Slant six running rough/lean and not performing right. |
https://www.slantsix.org/forum/viewtopi ... level+1920 |
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| Author: | matv91 [ Fri Feb 15, 2019 8:47 pm ] |
| Post subject: | Re: Slant six running rough/lean and not performing right. |
https://www.slantsix.org/forum/viewtopi ... ring+block In the 4th linked picture, the main jet hole. Just above and to the right in that second well is small hole, make sure its open. Its feeds fuel into main system air well. |
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| Author: | matv91 [ Fri Feb 15, 2019 9:34 pm ] |
| Post subject: | Re: Slant six running rough/lean and not performing right. |
https://www.slantsix.org/forum/viewtopi ... ring+block In the picture with screw driver in main jet hole. The jet sits at bottom of main well.The air well is just to the right of main well. The main system air bleed delivers air to air well. The small hole at bottom of air well delivers fuel. |
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| Author: | matv91 [ Fri Feb 15, 2019 10:17 pm ] |
| Post subject: | Re: Slant six running rough/lean and not performing right. |
When the carb is built 2 holes are drilled to connect the air well to the main well. Depending on engine speed and load, fuel level will rise or fall in air well.At low load fuel level is low so holes deliver air, as load increases fuel level goes up starts to block lower air hole, sort of a mix less air more fuel. As load goes up fuel level goes up to second hole, so instead of all air its mixture of fuel and air. |
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| Author: | matv91 [ Fri Feb 15, 2019 10:43 pm ] |
| Post subject: | Re: Slant six running rough/lean and not performing right. |
In that picture under the white power valve link there are 2 plugged holes. After the cross holes were drilled the outside hole was plugged. Fuel level at 27/32 puts fuel level some where close to those holes |
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| Author: | matv91 [ Sat Feb 16, 2019 12:32 pm ] |
| Post subject: | Re: Slant six running rough/lean and not performing right. |
http://www.tocmp.com/manuals/Carbs/Holl ... _53B5.html Not a 1920 but shows main and air wells connected |
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| Author: | matv91 [ Sat Feb 16, 2019 1:02 pm ] |
| Post subject: | Re: Slant six running rough/lean and not performing right. |
1966 100 percent gasoline original float setting gave correct fuel level. Current day fuel may not,density of fuel is different. |
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| Author: | JukkaK [ Sun Feb 17, 2019 1:34 am ] |
| Post subject: | Re: Slant six running rough/lean and not performing right. |
Thanks, I'll take a look at all these things you mentioned, altough the carb seems quite clean but of cource it's not possible to see into those tiny holes. I intented to take the carb off the car yesterday but I ran into other problems friday evening and I had to use the saturday for taking the transmission out and inspect the clutch and it's actuator mechanism because it wasn't all of a sudden disengaging properly, it turned out to be some rivets gone bad in the clutch disc, hammered the rivets back so that they'll stay on. All good now. |
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| Author: | JukkaK [ Sun Feb 17, 2019 9:17 am ] |
| Post subject: | Re: Slant six running rough/lean and not performing right. |
I did some rough testing by restricting that idle air bleed hole. I put a few tiny copper wies from electrical conductor together and slid the other end to that idle air bleed hole and tied the other end into the metal part which the air filter housing is attached to. It actually seems to work a bit better at highway at light throttle, still not smoothly though. I'll try to add couple more tiny copper wires to restrict it even more and see if that further helps. It just seems that the restriction I'm doing is quite huge, could the idle air bleed hole really be that much too big. Also, I'm not 100% sure but after driving, the surroundings of the idle air bleed hole seems like there has been fuel coming out of it which I believe is not the purose of it. Then again, could it be because I restricted the air bleed but didn't adjust the idle air/fuel mixture... |
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