Sputtering at high speeds.

guevara42

Member

Dec 28, 2006

68

0

6

Jacksonville, Fl

Dec 11, 2011

#1

• Dec 11, 2011

• #1

Hey folks, I have a 66 coupe, 289. Car sputters at speeds starting at 65-70 and gets worse if I try to go faster. I have changed everything I can think of. Fuel filters, fuel pump, I put in an electronic ignition about a year ago. New gas tank tank and sending unit. Anything else you guys can recommend I try? I did notice that I need new exhaust manifold gaskets because i can hear a leak and visually confirmed it. TIA.

 

M

MitchGT

Member

Apr 1, 2005

204

0

17

Dec 11, 2011

#2

• Dec 11, 2011

• #2

guevara42 said:

Hey folks, I have a 66 coupe, 289. Car sputters at speeds starting at 65-70 and gets worse if I try to go faster. I have changed everything I can think of. Fuel filters, fuel pump, I put in an electronic ignition about a year ago. New gas tank tank and sending unit. Anything else you guys can recommend I try? I did notice that I need new exhaust manifold gaskets because i can hear a leak and visually confirmed it. TIA.

Click to expand...

Clean out the filter in the carb. some have them. exhaust leak would not cause this.

 

guevara42

Member

Dec 28, 2006

68

0

6

Jacksonville, Fl

Dec 11, 2011

#3

• Dec 11, 2011

• #3

MitchGT said:

Clean out the filter in the carb. some have them. exhaust leak would not cause this.

Click to expand...

Fuel filter has been replaced recently. Thanks,

 

HookandLadder

Founding Member

Feb 17, 2001

261

0

17

St Louis

Dec 11, 2011

#4

• Dec 11, 2011

• #4

Check your coil. Could be cutting out at higher speed.

 

rbohm

Founding Member

Apr 12, 2002

6,698

550

204

tucson,az

Dec 12, 2011

#5

• Dec 12, 2011

• #5

start with the basics, and dont take anything for granted, even the new parts you put on as it is possible that even they are defective.

1: check your fuel pressure at speed

2: check your initial timing as well as your advance curve

3: check your fuel flow

4: check your air filter

5: check your plug wires and plugs

6: check your coil

7: check for vacuum leaks

 

gikort

Member

Nov 26, 2010

82

1

9

Dec 12, 2011

#6

• Dec 12, 2011

• #6

What about the float level in your carb?

 

guevara42

Member

Dec 28, 2006

68

0

6

Jacksonville, Fl

Dec 12, 2011

#7

• Dec 12, 2011

• #7

I will check the fuel pressure and the flow. This only started happening about a week ago. I did put in a new coil about 6 months ago and I think I will try new plugs and wires next. That's the only thing I have not done. Thanks.

 

WTFO

Member

Nov 20, 2011

53

1

8

Clarks-Vegas

Dec 13, 2011

#8

• Dec 13, 2011

• #8

What carb and distributor are you running?

 

guevara42

Member

Dec 28, 2006

68

0

6

Jacksonville, Fl

Dec 13, 2011

#9

• Dec 13, 2011

• #9

WTFO said:

What carb and distributor are you running?

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Carb and distributor are original. Motorcraft 2bbl carb and the original distributor with electronic point system. Carb was rebuilt less than a year ago and it's been a few years since dist. has been rebuilt. Opened up carb and it's as clean as can be. Thought I may find gunk but it was good. Thanks.

 

WTFO

Member

Nov 20, 2011

53

1

8

Clarks-Vegas

Dec 14, 2011

#10

• Dec 14, 2011

• #10

It's vacuum advance then? Bad vacuum pot on the distro maybe? Does the car idle okay? Could be a vacuum leak on the carb somewhere. Bad accelerator pump? Easy way to find a vacuum leak is to start your car and let it warm up completely then using an un-lit propane torch, slowly pass the torch nozzle by anything on or near the intake. If the idle goes up at a particular spot, you've found your leak. It's a pain with a mechanical fan blowing under the hood. Good luck!!

 

horseballz

10 Year Member

Sep 30, 2009

824

19

49

Las Vegas, NV

Dec 15, 2011

#11

• Dec 15, 2011

• #11

I use a 6-12 inch piece of hose on the nozzle of the propane torch. It allows easier access to the tight spots. I'm guessing your sputtering is due a timing curve issue. Try disconnecting and plugging the vacuum advance and go for a drive. If the sputter goes away or changes, you'll know if you're on the right track. Does the problem happen at the same/similar engine RPM/load regardless of what gear you are in?
My $.02,
Gene

 

PoppyMod

Member

Jun 27, 2010

617

6

19

Severna Park, MD

Dec 16, 2011

#12

• Dec 16, 2011

• #12

Hi,
Check the wires to the "+" and "-" or "Dist" or "Bat" are correct. A polarity issue will cause your sputtering, as well.
As noted, you can be experiencing a lean condition as others have mentioned. Check all of your plugs too.
Good Luck!

 

Hack

15 Year Member

Mar 23, 2004

1,945

13

69

Minneapolis

Dec 16, 2011

#13

• Dec 16, 2011

• #13

I noticed that you didn't mention plugs/wires/cap/rotor condition. I have had vehicles with a miss-fire on the highway that was caused by worn ignition parts.

 

A

azduffee

New Member

Dec 18, 2011

5

0

1

Dec 18, 2011

#14

• Dec 18, 2011

• #14

guevara42 said:

Hey folks, I have a 66 coupe, 289. Car sputters at speeds starting at 65-70 and gets worse if I try to go faster. I have changed everything I can think of. Fuel filters, fuel pump, I put in an electronic ignition about a year ago. New gas tank tank and sending unit. Anything else you guys can recommend I try? I did notice that I need new exhaust manifold gaskets because i can hear a leak and visually confirmed it. TIA.

Click to expand...

I once had a little piece of gasket in the fuel bowl that would get sucked into one of the jets at freeway speeds causing the same thing you are experiencing.

 

guevara42

Member

Dec 28, 2006

68

0

6

Jacksonville, Fl

Dec 22, 2011

#15

• Dec 22, 2011

• #15

I finally gave in and took the car to a pro. I did everything stated by everyone. I changed everything, coil, wires, plugs, vacuum advance, filters. I opened up carb and looked extremely clean. The timing was dead on. Im waiting for a response from the mech. I'll let you guys know what it was. Thanks fellas. P.S.

 

PoppyMod

Member

Jun 27, 2010

617

6

19

Severna Park, MD

Dec 22, 2011

#16

• Dec 22, 2011

• #16

guevara42 said:

I finally gave in and took the car to a pro. I did everything stated by everyone. I changed everything, coil, wires, plugs, vacuum advance, filters. I opened up carb and looked extremely clean. The timing was dead on. Im waiting for a response from the mech. I'll let you guys know what it was. Thanks fellas. P.S.

Click to expand...

Hi,
I would advise, you to request the mechanic, to return any replaced parts and provide a detailed explanation. It can only benefit you in the future.
Good Luck ......Merry Christmas!

 

guevara42

Member

Dec 28, 2006

68

0

6

Jacksonville, Fl

Jan 2, 2012

#17

• Jan 2, 2012

• #17

After all that, it was a bad distributor. I swapped with a new one and car runs great. Thanks for all your help.

 

PoppyMod

Member

Jun 27, 2010

617

6

19

Severna Park, MD

Jan 2, 2012

#18

• Jan 2, 2012

• #18

guevara42 said:

After all that, it was a bad distributor. I swapped with a new one and car runs great. Thanks for all your help.

Click to expand...

Glad to hear it's fixed.
....and to think in could have been a $3 capacitor?
Happy Motoring!