Hesitation and Rough Idle

Project 64 Impala Wagon · 06-09-2009, 04:17 PM

Hey guys sure you remember when I had the "stalls everytime I let of the gas", thread.

Well the cars up and running now with a TH350, on the column.

My symptons now are that it has a rough idle and if I dont baby the gas pedal upon take off it will try to stall on me.

NEW PARTS:
plugs

points and condesor(adjusted w/ dwell meter)

timing checked and set

vacumn lines(from trans to intake and pcv line also)

fuel filter

air filter

Once I am at cruising speed I dont notice anything but anytime I accelerate, you can hear and feel it missing and sputtering.

I am still not sure what the two screws on the front of the carb are and if they need adjusting so if someone and educate me on those that would be great.

Also my thought is to rebuild the carb and go from there.

What are your thoughts

Thanks in advance

Bernie

**77Impala** · 06-09-2009, 08:37 PM

Carburetor accelerator pump is not giving enough fuel.

With the engine shut off and the air cleaner top removed you should be able to move the throttle and see it squirt a stream of gas from the jets in the throttle horn. That burst of fuel with the opening of the throttle plate gives you the acceleration you are needing. By babying the throttle you are gently opening the throttle plate at a rate that allows the engine to run, but not anywhere near what you want from it.

You may want to go ahead and do a full carb rebuild. The rebuild kit will have all parts including a new accelerator pump in it.

dintymoore · 06-10-2009, 07:39 PM

Is this a Rochester 4 barrel carb?

Have you adjusted the mixture?

I'd probably rebuild the carb since cars run great after you do and I'm sick so I find that kind of stuff fun. The guy that wrote the book on Rochesters said that only about 1 in 50 carbs actually need a rebuild kit, and I believe him - as long as the gaskets don't fall apart when you take it apart.

Parts do get worn out but more often it's old gas that congeals and makes a mucky paste that clogs up the carb.

I bought a steamer (cheap $40 KMart made by Shark) that is bad quality but the best thing I've ever had for cleaning carbs.

If you don't have a steamer, really hot water works great. Blow it out with compressed air when you're through.

But first I'd try a can of carb cleaner and adjust the mixture needles and set the idle to specs; that's ground zero.

Have you ever done that before?

Project 64 Impala Wagon · 06-12-2009, 07:37 PM

Quote:

Originally Posted by dintymoore

Is this a Rochester 4 barrel carb?

Have you adjusted the mixture?

I'd probably rebuild the carb since cars run great after you do and I'm sick so I find that kind of stuff fun. The guy that wrote the book on Rochesters said that only about 1 in 50 carbs actually need a rebuild kit, and I believe him - as long as the gaskets don't fall apart when you take it apart.

Parts do get worn out but more often it's old gas that congeals and makes a mucky paste that clogs up the carb.

I bought a steamer (cheap $40 KMart made by Shark) that is bad quality but the best thing I've ever had for cleaning carbs.

If you don't have a steamer, really hot water works great. Blow it out with compressed air when you're through.

But first I'd try a can of carb cleaner and adjust the mixture needles and set the idle to specs; that's ground zero.

Have you ever done that before?

No its the Rochester 2bbl
I bought the rebuild kit this morning, but after opening it and see the instructions, I think I am going to ask a friend of mine to do it while I watch and ask questions.
It looks very intimadating
I will report back once done to let you guys know if that was the root of my problems.
It will prob be Monday or so
thanks
Bernie

**77Impala** · 06-13-2009, 06:51 PM

Quote:

Originally Posted by Project 64 Impala Wagon

No its the Rochester 2bbl

Is it the Rochester 2GC?

Project 64 Impala Wagon · 06-13-2009, 08:45 PM

Still havent dont the rebuild but did buy new wires and no change so far.

Today on the way to work I started getting a ton of white smoke out the tailpipes upon take off. After getting out of first gear the white smoke either goes away or I just dont see it because i am moving, not sure
Any ideas what that is?
Thanks
Bernie

**77Impala** · 06-13-2009, 09:28 PM

May be oil burning if the smoke is blue/gray color. Bad valve guide seals and/or worn piston rings would cause that.

White usually means that you have coolant getting into the combustion chamber. Could be a bad head gasket. Have you checked the coolant and oil lately? If the oil is a tan creamy color then you have a problem. Or if your coolant has oil in the top of the radiator then another clue of a problem. You can also look and see if you get air bubbles in the radiator while the engine is at operating temp and the cap is off which is a clue that you have either a blown head gasket, head or cylinder wall.

Project 64 Impala Wagon · 06-14-2009, 04:28 PM

Quote:

Originally Posted by 77Impala

May be oil burning if the smoke is blue/gray color. Bad valve guide seals and/or worn piston rings would cause that.

IF this is the case can I drive it or will it hurt the motor??

White usually means that you have coolant getting into the combustion chamber. Could be a bad head gasket. Have you checked the coolant and oil lately? If the oil is a tan creamy color then you have a problem. Or if your coolant has oil in the top of the radiator then another clue of a problem. You can also look and see if you get air bubbles in the radiator while the engine is at operating temp and the cap is off which is a clue that you have either a blown head gasket, head or cylinder wall.

I know that if its a head gasket I have to get it fixed ASAP. That would require new head gaskets and what ever other gaskets I need due to having to disassemble the top part of the engine correct?
Thanks
Bernie

**77Impala** · 06-14-2009, 04:39 PM

You can still drive it. If just from the valve guide seals you will notice at start up and after a few minutes most if not all will go away. I have driven my car for over 50K miles this way. You may want to run SeaFoam or other high quality combustion/fuel injection cleaner through the tank to help clean out any carbon that builds up from burning oil.

If it is from the rings then though you can drive it it will not be long before you will have to overhaul the motor. Now the more you drive it with bad rings the more likely you will have a bigger overhaul bill if you rebuild the current motor.

If it is only oil burning smoke that you are seeing right now the worst case would be that you will have to clean the plugs every 1 to 3 thousand miles and use fuel/combustion cleaner more often.

**77Impala** · 06-14-2009, 04:40 PM

Quote:

Originally Posted by Project 64 Impala Wagon

That would require new head gaskets and what ever other gaskets I need due to having to disassemble the top part of the engine correct?
Thanks
Bernie

Yes you are correct.

Project 64 Impala Wagon · 06-22-2009, 05:24 PM

I went back out today and used some carb cleaner and sprayed the middle gasket area on the carb and it bog down just a little. That means there a vacum leak right there correct?

Still havent rebuilt it yet and I drove it on Sat and Sun and it drove decent(i adjusted the idle up some) Didnt stall but still cant stand on it on take off.

Also found out today that I am getting a 1990 350 block to freshen up and my buddy has some heads for it and really all I need to get is the intake and carb. Its a 4bolt main out of a truck. I am going to disassemble it prob Wednesday this week to make sure its good to use. Friend of mine called in a payback favor to another guy so I think I am getting it for $50.
Well see I will check back in sometime after Wed with pics and what not.
Thanks for the help
Bernie

dintymoore · 07-01-2009, 03:09 PM

Good news on the engine Bernie!

I'm not sure which gasket you mean but most carbs are attached to the intake manifold by four (I think 1/2") bolts and sometimes they are loose. It doesn't hurt to check them.

06-09-2009, 04:17 PM	#1 (permalink)
Project 64 Impala Wagon Member Join Date: Feb 2009 Location: FL Posts: 93	Hesitation and Rough Idle Remove this ad! Hey guys sure you remember when I had the "stalls everytime I let of the gas", thread. Well the cars up and running now with a TH350, on the column. My symptons now are that it has a rough idle and if I dont baby the gas pedal upon take off it will try to stall on me. NEW PARTS: plugs points and condesor(adjusted w/ dwell meter) timing checked and set vacumn lines(from trans to intake and pcv line also) fuel filter air filter Once I am at cruising speed I dont notice anything but anytime I accelerate, you can hear and feel it missing and sputtering. I am still not sure what the two screws on the front of the carb are and if they need adjusting so if someone and educate me on those that would be great. Also my thought is to rebuild the carb and go from there. What are your thoughts Thanks in advance Bernie __________________ 64 Bel Air Wagon - Parts Car 64 Impala Wagon a.k.a "Project 64" http://www.cardomain.com/ride/3275008 95 Impala SS a.k.a "1RawSS" (SOLD) http://www.cardomain.com/ride/263617

06-09-2009, 08:37 PM	#2 (permalink)
77Impala Administrator Join Date: Nov 2007 Location: North TX Posts: 2,696 View My Garage 77Impala	Carburetor accelerator pump is not giving enough fuel. With the engine shut off and the air cleaner top removed you should be able to move the throttle and see it squirt a stream of gas from the jets in the throttle horn. That burst of fuel with the opening of the throttle plate gives you the acceleration you are needing. By babying the throttle you are gently opening the throttle plate at a rate that allows the engine to run, but not anywhere near what you want from it. You may want to go ahead and do a full carb rebuild. The rebuild kit will have all parts including a new accelerator pump in it. __________________ 1977 Impala Sedan, 5.0L, TH200, 3.25:1, 82K miles, 27 Lifetime Warranty Parts. Does not like Dodge Pickups rear bumpers! 1997 Dodge Ram B2500, 5.2L, 36RH, 3.21:1, 352K miles, 10 Lifetime Warranty Parts.

06-10-2009, 07:39 PM	#3 (permalink)
dintymoore Senior Member Join Date: Jan 2009 Location: Oahu Posts: 679	Is this a Rochester 4 barrel carb? Have you adjusted the mixture? I'd probably rebuild the carb since cars run great after you do and I'm sick so I find that kind of stuff fun. The guy that wrote the book on Rochesters said that only about 1 in 50 carbs actually need a rebuild kit, and I believe him - as long as the gaskets don't fall apart when you take it apart. Parts do get worn out but more often it's old gas that congeals and makes a mucky paste that clogs up the carb. I bought a steamer (cheap $40 KMart made by Shark) that is bad quality but the best thing I've ever had for cleaning carbs. If you don't have a steamer, really hot water works great. Blow it out with compressed air when you're through. But first I'd try a can of carb cleaner and adjust the mixture needles and set the idle to specs; that's ground zero. Have you ever done that before? __________________ Have you visited the Impala Forums Store today? Thousands of cars & parts for sale!

06-13-2009, 08:45 PM	#6 (permalink)
Project 64 Impala Wagon Member Join Date: Feb 2009 Location: FL Posts: 93	Still havent dont the rebuild but did buy new wires and no change so far. Today on the way to work I started getting a ton of white smoke out the tailpipes upon take off. After getting out of first gear the white smoke either goes away or I just dont see it because i am moving, not sure Any ideas what that is? Thanks Bernie __________________ 64 Bel Air Wagon - Parts Car 64 Impala Wagon a.k.a "Project 64" http://www.cardomain.com/ride/3275008 95 Impala SS a.k.a "1RawSS" (SOLD) http://www.cardomain.com/ride/263617

06-13-2009, 09:28 PM	#7 (permalink)
77Impala Administrator Join Date: Nov 2007 Location: North TX Posts: 2,696 View My Garage 77Impala	May be oil burning if the smoke is blue/gray color. Bad valve guide seals and/or worn piston rings would cause that. White usually means that you have coolant getting into the combustion chamber. Could be a bad head gasket. Have you checked the coolant and oil lately? If the oil is a tan creamy color then you have a problem. Or if your coolant has oil in the top of the radiator then another clue of a problem. You can also look and see if you get air bubbles in the radiator while the engine is at operating temp and the cap is off which is a clue that you have either a blown head gasket, head or cylinder wall. __________________ 1977 Impala Sedan, 5.0L, TH200, 3.25:1, 82K miles, 27 Lifetime Warranty Parts. Does not like Dodge Pickups rear bumpers! 1997 Dodge Ram B2500, 5.2L, 36RH, 3.21:1, 352K miles, 10 Lifetime Warranty Parts.

06-14-2009, 04:39 PM	#9 (permalink)
77Impala Administrator Join Date: Nov 2007 Location: North TX Posts: 2,696 View My Garage 77Impala	You can still drive it. If just from the valve guide seals you will notice at start up and after a few minutes most if not all will go away. I have driven my car for over 50K miles this way. You may want to run SeaFoam or other high quality combustion/fuel injection cleaner through the tank to help clean out any carbon that builds up from burning oil. If it is from the rings then though you can drive it it will not be long before you will have to overhaul the motor. Now the more you drive it with bad rings the more likely you will have a bigger overhaul bill if you rebuild the current motor. If it is only oil burning smoke that you are seeing right now the worst case would be that you will have to clean the plugs every 1 to 3 thousand miles and use fuel/combustion cleaner more often. __________________ 1977 Impala Sedan, 5.0L, TH200, 3.25:1, 82K miles, 27 Lifetime Warranty Parts. Does not like Dodge Pickups rear bumpers! 1997 Dodge Ram B2500, 5.2L, 36RH, 3.21:1, 352K miles, 10 Lifetime Warranty Parts.

06-22-2009, 05:24 PM	#11 (permalink)
Project 64 Impala Wagon Member Join Date: Feb 2009 Location: FL Posts: 93	I went back out today and used some carb cleaner and sprayed the middle gasket area on the carb and it bog down just a little. That means there a vacum leak right there correct? Still havent rebuilt it yet and I drove it on Sat and Sun and it drove decent(i adjusted the idle up some) Didnt stall but still cant stand on it on take off. Also found out today that I am getting a 1990 350 block to freshen up and my buddy has some heads for it and really all I need to get is the intake and carb. Its a 4bolt main out of a truck. I am going to disassemble it prob Wednesday this week to make sure its good to use. Friend of mine called in a payback favor to another guy so I think I am getting it for $50. Well see I will check back in sometime after Wed with pics and what not. Thanks for the help Bernie __________________ 64 Bel Air Wagon - Parts Car 64 Impala Wagon a.k.a "Project 64" http://www.cardomain.com/ride/3275008 95 Impala SS a.k.a "1RawSS" (SOLD) http://www.cardomain.com/ride/263617

07-01-2009, 03:09 PM	#12 (permalink)
dintymoore Senior Member Join Date: Jan 2009 Location: Oahu Posts: 679	Good news on the engine Bernie! I'm not sure which gasket you mean but most carbs are attached to the intake manifold by four (I think 1/2") bolts and sometimes they are loose. It doesn't hurt to check them. __________________ Have you visited the Impala Forums Store today? Thousands of cars & parts for sale!

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