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Roy
Roy, import/domestic specialest
Category: Chevy
Satisfied Customers: 6197
Experience:  ASE master tech for 40 years
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I replaced the PVC valve and the truck stays "on". When I

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Roy, I replaced the PVC valve and the truck stays "on". When I place my hand over the carburetor the idle goes up. The idle on the truck surges up and down when the truck is at idle. What should I try next?

hello, my name is ***** ***** I will be glad to assist you. please allow me a couple of minutes to gather some basic info.

Roy

good morning

by doing that tells me it is running lean. you need to adjust the idle mixture screws at the bottom of the carb.

Roy

Customer: replied 1 month ago.
Should I take the truck to my local mechanic to adjust the idle mixture screws?

no, you can do it your self. remove the air filter assembly. use a light and see if the screws have regular flat heads or torx heads. you may need to get the tool for them if they do. parts stores carry them for about 10 bucks.

then with the engine warm, adjust one side at a time out a little bit. the engine rpm will rise. back out the screw until the engine does not increase rpm any more. do it to both sides.

Roy

Customer: replied 1 month ago.
Ok Roy, I will go to my house where the truck is located and see if I can find these screws on the carburetor. I thought you said the screws would be capped? Can I send you a picture of the carburetor?

you bet. send me the pictures

like I said before, you may have to remove the carb and remove the caps to access the screws.

it is not that hard

Roy

Customer: replied 1 month ago.
I have too remove the whole carburetor (that's scary). Did I tell you I called the distributor (Summit Racing) and they said the mixture screws did not need adjustment and that this is a simple carburetor that only needs the idle screw adjusted? I'm nervous but, then excited at the same time because I have never removed a carburetor. What can go wrong? How do you remove it? Does the placement have to be exact? Will I have more vacuum leaks? I trust you can help me.

yes you did and I responded to that saying they cannot adjust a carb to your engine without it being on the truck.

you will need a 5/8 line wrench to remove the fuel line.

a 3/4 wrench to remove the line for booster in the rear.

flat head screw driver to remove vacuum lines and choke wire.

3/8 rachet, 3 inch extension and 1/2 inch socket to remove the 4 bolts that hold it to the manifold

Roy

Customer: replied 1 month ago.
after I remove the carburetor, I make the adjust on the mixture screw for one side, then place the carburetor back on the intake and see how the truck runs. Then remove the carburetor again, adjust the other mixture screw, place the carburetor back on the intake and see how the truck is idling?

after you remove it, the caps have to be removed and then re install the carb. then you will adjust the carb with the engine running

Customer: replied 1 month ago.
I guess I'm getting confused with the location of the mixture screws. Will go to my house and get pictures for you. Thanks.

they are on the bottom of the carb in the front

Customer: replied 1 month ago.
Roy, I tried sending you my pictures but, it says the file is too big (when I do Add files). Now the truck takes some time to stay "on" because I have to keep pumping the gas and then the engine gets warmer and the engine stays "on" at high idle. Also, I'm worried about letting the engine run because I don't have a way to tell the oil pressure or temperature (sure would like to send pictures of my engine)? When I put the truck on Drive or Reverse the idle gets way low.

yep, I hear you. we will deal with that once you get the caps off.

Customer: replied 1 month ago.

nice camaro

Customer: replied 1 month ago.
Wrong picture.
Customer: replied 1 month ago.
Do you have an email address?

the site will block it. cannot give out personal info. I know what the carb looks like. I have rebuilt hundreds of them over the years.

Roy

Roy

Customer: replied 1 month ago.
Is there a gasket between the carburetor and intake? What keeps the gas from going all over the place?

yes there is.

the fuel enters through the venturi in the carb. the gasket does not seal off fuel, just vacuum

Roy

Customer: replied 1 month ago.
Roy, I don't know how to remove the carburator idle mechanism stuff? See the cable going into the firewall there are no screws to remove.
Customer: replied 1 month ago.
Roy, do you see the black cap on the left next to the fuel line port to carb and on the right front of the carb a small and large black cap? Are these the caps to be removed or are the caps underneath the carburetor?

the accelerator cable has a clip you remove and it comes right off.

the trans cable underneath you have to slide the black connector forward to remove it from the linkage.

no need to worry about the black caps. they are vacuum blocks

Roy

Customer: replied 1 month ago.
Roy, frustrated!! I cannot remove the cables. I pulled themout of their holders. Do you use a screwdriver to undo the tabs? Is it a solid piece of plastic? Where is the separation point on each cable?

the trans cable on the bot***** *****nkage, take the black piece, hold the throttle closed and slid it forward to release. you need 2 hands to do it.

Roy

Customer: replied 1 month ago.
What? Are you talking about this cable? What does the little ball do? How does it separate? There isn't much travel on this cable. What do you mean by hold the throttle closed?
Customer: replied 1 month ago.

you have the accelerator cable off.

the bottom cable that goes to the bracket. the end that is on the carb linkage slides forward to remove.

yes that is the cable. the black end on the carb linkage slides forward to remove. it is tight but slides forward.

Roy

Customer: replied 1 month ago.
OMG, I thought you meant the little black ball on the bracket slides forward. Its not, it's this one. Whew!! Ok, what about this cable?

just take a screw driver and pry it off. it goes over the rubber on the carb mount

Roy

Customer: replied 1 month ago.
Are you saying to pry this end of the cable off with a screwdriver?
Customer: replied 1 month ago.
Got it, couldn't see the baby c-clip. Ok, now I can remove the 4 bolt down screws?

yes

got kid duty. be back on around 3

Customer: replied 1 month ago.
No problem, its 12:58pm here in Kyle, Texas. I'll be going back to work at the IRS starting Monday so my time on this truck will be less.
Customer: replied 1 month ago.
I'm guessing the 2 with gel stuff need to be unsealed. I took a front picture of the carb and it shows to 2 holes with some kind of pin looking thing in each. Are those the mixture screws?
Customer: replied 1 month ago.
Bottom of carb.
Customer: replied 1 month ago.
More bottom pictures

nice, caps are already off. they are the screws.

you need the tool for adjusting.

let me see if I can find it

Roy

https://shop.advanceautoparts.com/p/thexton-carburetor-adjusting-tool-thx350/22983647-P?searchTerm=carb+adjusting+tool

Customer: replied 1 month ago.
I really didn't need to remove the carburator?

now you have a great view of the screws you will be turning.

also, good experience for you.

Customer: replied 1 month ago.
I'm waiting for the carburetor adjustment tool to arrive on Wednesday. Can I paint the intake manifold while it is on the engine?

yep, paint away

Roy and other Chevy Specialists are ready to help you

thank you

Customer: replied 1 month ago.
Roy, I think I might have cross threaded the nut for the fuel filter because the nut keeps turning and turning. Can it be fixed?

is it the line or the carb that is stripped??

Customer: replied 1 month ago.
I sent you some pictures showning you the big nut that screws onto the carburetor and one showing you the housing on the carburetor looks like I did a number on the carb housing?

yep, that is a problem. you are going to need to find a fitting with longer threads to grab the good ones inside. you can try NAPA.

Roy

Customer: replied 29 days ago.
Roy, I would like to remove the water pump to paint it, also. Is it hard to remove? Should I buy a new one?

easy to remove. remove the belts, fan assembly lower hose and heater hose at the top. the alternator bracket and power steering brackets have to be moved. then 4 bolts and it is off.

a new one is cheap. a rebuilt is about 30 bucks

Customer: replied 29 days ago.
do you recommend I buy a new one ?Since it isn't that expensive, it's already painted, more reliable because old on looks like its been there awhile. The bolts are so tight, is that normal? I'm considering buying an air compressor with a ratchet. Or should I do everything manually?

no, the new pump will come un painted. you can paint it prior to installation.

yes, air compressor and ratchet are good tools. good addition to your tool box

Roy

Customer: replied 29 days ago.
Was looking at a California compressor online. What HP? How much PSI? Will use it mainly to work on my cars.

ok harbor freight has a 21 gallon stand up with 125 psi. more than enough for you. only 149

Roy

Customer: replied 29 days ago.
I want a very quiet compressor since I have anxiety and depression. What compressor do you recommend? Please send me a part number or link. Something that my son will use in the future.
Customer: replied 29 days ago.
I have decided to build a garage/workshop.

compressors are not quiet at all. they have a motor running to produce the air pressure.

https://www.harborfreight.com/catalogsearch/result/index/?dir=asc&order=EAScore%2Cf%2CEAFeatured+Weight%2Cf%2CSale+Rank%2Cf&q=Air+Compressors

Customer: replied 29 days ago.
Ok Roy, I bought the compressor. What attachments will I need to remove the water pump? Thanks.

attachments???

Customer: replied 29 days ago.
I have never used a compressor. What air lines or ratchet fits this compressor. Can you send me part numbers? Is there a kit that has all the accessories?

you will need a 25 foot air hose. you will need fittings to attach the air hose to the compressor and also to the air equipment you are using. you can get them at any parts store as they are extremely common. not expensive at all.

as far as the air tools, I would go to a harbor freight and they have kits that have air gun, ratchet and hammer in one kit. you will need sockets as well.

Roy