4 barrel roch. carb question

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bill

Royal Smart Person
Jul 11, 2008
2,332
11
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southside va/lake gaston
cutlassguy said:
http://www.youtube.com/watch?v=TDNd_YwXa5A&context=C43033eaADvjVQa1PpcFNK0MJ41ubcSQ-5dFM9tY819SBVqMjHGE0=
That looks pretty good to me on the gauge. When you pulled the plugs, did they all look similar? Can you show one on video/pic? Your distributor may have broken a spring in the advance...or it may have a bad module? Just throwing things out there for you to check. Advance/AZ can check the module to make sure its good. Check the rotor button for play in the shaft. And, if you have access to a vacuum pump, put vacuum on the advance on the carb to see that its working right....shouldnt take much to make it move...10inches
 

cutlassguy

Master Mechanic
Dec 15, 2011
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That looks pretty good to me on the gauge. When you pulled the plugs, did they all look similar? Can you show one on video/pic? Your distributor may have broken a spring in the advance...or it may have a bad module? Just throwing things out there for you to check. Advance/AZ can check the module to make sure its good. Check the rotor button for play in the shaft. And, if you have access to a vacuum pump, put vacuum on the advance on the carb to see that its working right....shouldnt take much to make it move...10inches

yah all the plugs had a simular look to them...a lil carbon on the flat cirle part and a little yellow-ness to the metal tip, but nothing id consider abnormal. im gonna change them to AC's tomorrow so i'll take a pic of all of them and post it on here. ill check out the spring cuz when i changed the cap and rotor i noticed it all looked a lil rusty and shitty looking so i guess its a possibility. is the module the white plastic thing inside the dist.? i know what your talking about but id need a few more details to do it myself...ive never learnt too much about carbs an vacuum so ima noob when it comes to this. by rotor button do you mean the metal tab that sticks up on it? "put vacuum on the advance on the carb to see that its working right." do you mean hook vac up to the line that goes to the vac. adv. on the dist,? or something on the carb?
 

bill

Royal Smart Person
Jul 11, 2008
2,332
11
38
southside va/lake gaston
cutlassguy said:
..... when i changed the cap and rotor i noticed it all looked a lil rusty and shitty looking so i guess its a possibility. is the module the white plastic thing inside the dist.? i know what your talking about but id need a few more details to do it myself...ive never learnt too much about carbs an vacuum so ima noob when it comes to this. by rotor button do you mean the metal tab that sticks up on it? "put vacuum on the advance on the carb to see that its working right." do you mean hook vac up to the line that goes to the vac. adv. on the dist,? or something on the carb?
The module is in the distributor, under the rotor button. Should be plugged into two other parts on each end. Usually has two screws holding it in. The vacuum advance is the cone shaped thing on the distributor. Gotta look inside the distributor while you put a vacuum on it with a vacuum pump to see it moving. The rusty distributor is not a good sign. There shouldnt be water getting in it at all to make it rust. The rotor button is under the cap when you take it off....its round, with two screws holding it on.
 

cutlassguy

Master Mechanic
Dec 15, 2011
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after a good look i decided to just buy a brand new billit accel HEI distributor today. popped it in along with new ac delco plugs and a fuel filter and its still doing the same thing. now theres a new dist.,cap, rotor, coil, module...etc, wires, plugs, fuel filter, air filters clean and fairly new. pvc isnt plugged...no vac leaks...do you know how i can test my fuel pump with that gauge i have? i dont have any other attchments just the plastic cone one so i cant really attach it to any lines, just hold it there. i ripped oped the old f filter and it had a little bit of shavings and gunk but nothing un-usual, ive definately had and seen worse that didnt cause any issues. i have a fairly new fuel pump in the closet so im almost thinking of just changing it for the hell of it. i cant really even think about what else to replace to eliminate the problem. does a mechanical fuel pump gradually lose pressure or does it just flop out. also now my temp gauge isnt working all of a sudden...wierd i changed the plugs and filter and now no gauge. theres a wire that goes from a clip on top of the thermostat housing to the 2 prong plug on my carb. could that have anything to do with it? i can take a pic of it if you need. also do you still wanna see the old set of plugs i just pulled out of it? they're all pretty much the same so i dont think there any issues in a piticular piston. the only other thing i can think of is that the choke seems to open pretty fast so its fully opened way before the motor warms up but even if i let it fully warm up it doesnt make a difference. now it boggs out with any acceleration unless i hammer it or feather it. i still have to set the timing exactly at 8 again but i know i pretty much have it where it was before and i triied a few different places just by ear and it made a minimal difference. what the hell else could be causing this? lol its seriously making me crazy, cant sleep...old ladys talkin and im thinkin about atmosheric pressure...and last question would it make sense that my mixture screws went out on they're own? it feels like a bad miss or a bad vac leak but everything ive done says its good... :blam:
 

cutlassguy

Master Mechanic
Dec 15, 2011
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i cant remember if i mentioned this before but theres a vacumm tree thing thats screwed into the intake and it has a black plastic piece on top that has a rubber fitting with probaly 6 or 7 different vac lines running into it from the carb and heading to the vac. adv., EGR, etc...anyhow the plastic piece can rotate in the part thats screwed into the intake...should that be? or should it be a solid piece. actually now that i think about it if it was leaking it would have probaly showed up on the guage test eh?
 

bill

Royal Smart Person
Jul 11, 2008
2,332
11
38
southside va/lake gaston
Are you getting vacuum to the distributor advance? You can tell by pulling off the vacuum hose and the motor will change tune and act like its running rough. Make sure you set the timing with that vacuum hose disconnected and plugged and the engine warmed up. What altitude are you at? If your above 5k ft, that would make a difference w/ the fuel/air ratio. The carb may still be part or all of the issue too. The power valve may be sticking or the diaphram in it may be bad.
 

cutlassguy

Master Mechanic
Dec 15, 2011
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yep its getting vac and i timed it with it disconnected and plugged. i dont think the altitude has much to do with anything cause it was running good then all off a sudden started acting up. have you ever heard of the mixture screws just going out on they're own? last night i came home for about 15 minutes then went back out and it ran pretty good for a few minutes so i figured the choke spring cooled a bit and it was closing the butterfly enough to allow a good mixture. is there a chance the choke spring got weak and now its opening too fast and doesnt have enough resistance? still kinda strange tho considering even when its fully warm it still feels like its bogging out unless i giver atleast half pedal...from everything i see im still kinda assuming it has something to do with the choke or carb but im not sure of how i can test it.
 

bill

Royal Smart Person
Jul 11, 2008
2,332
11
38
southside va/lake gaston
any updates? did ya fix the problem?
 
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