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Discussion Starter #1
Greetings,

I have a Holley EFI installed on my 65 Mustang 289 and have a "jerky" response when applying pressure to the gas pedal. By that I mean instant acceleration when applying light pressure in traffic. Its at the point, where I have to apply pedal pressure with my toes compared to entire foot to receive a slow increased take off. I had one mechanic "play" with new springs but have read this is what comes with EFI installation.

Anyone else experience this or have a fix? Thank you ! MD
 

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You are experiencing a common issue with the Holley Sniper EFI system. When I first installed mine, I could not accelerate from a dead stop without breaking the tires loose. I initially tried the progressive linkage and did not like it. It helped, but had it's own problems. I ultimately fabricated a throttle linkage extension that totally cured the issue.
750884
750885
 

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Discussion Starter #3
You are experiencing a common issue with the Holley Sniper EFI system. When I first installed mine, I could not accelerate from a dead stop without breaking the tires loose. I initially tried the progressive linkage and did not like it. It helped, but had it's own problems. I ultimately fabricated a throttle linkage extension that totally cured the issue.
View attachment 750884 View attachment 750885
Thank you for the info and time! So you're back to the same feeling the car had when it was on a carb? Is this something I could purchase somewhere or from you? What engine do you have and is your spring a Im seeing a standard one? Would love to be able to get the car back to a smooth driver bc it does take away some fun when behind the wheel currently.
 

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It is a 302 and it does now accelerate like a carburetor. Using the drawing I attached to my first response, you can easily make one yourself. The three holes are the only important part. The perimeter shape is up to you. The material is just a scrap piece of 1/16" (.0625) steel. The diameter of the top hole may vary, depending on your linkage rod.
The spring is one of two that come as a set made by Holley. They are available at most good parts stores.
 

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Discussion Starter #5
It is a 302 and it does now accelerate like a carburetor. Using the drawing I attached to my first response, you can easily make one yourself. The three holes are the only important part. The perimeter shape is up to you. The material is just a scrap piece of 1/16" (.0625) steel. The diameter of the top hole may vary, depending on your linkage rod.
The spring is one of two that come as a set made by Holley. They are available at most good parts stores.
Im going to post a picture of my set up today and see if you think what you made may fit. I'll probably outsource the creation of just to make sure its done correctly. Can I ask how this corrected the issue? Did it change the angle of the assembly?
 

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The Sniper out of the box really sucks for the linkage. Not sure what they were thinking. I installed the progressive linkage (opens 2 BBL first then eventually all 4 BBL). It is like night and day for actually using it. I only have a few miles on my car but very driveable.

I bought my parts at EFISystemPro.com.
 

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Discussion Starter #7
Thank you for the info. Ill update some pics of what my set up looks like today because I paid to have it installed. Id be open for any improvements really. Mine is the 2BBL.
 

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Discussion Starter #8
The Sniper out of the box really sucks for the linkage. Not sure what they were thinking. I installed the progressive linkage (opens 2 BBL first then eventually all 4 BBL). It is like night and day for actually using it. I only have a few miles on my car but very driveable.

I bought my parts at EFISystemPro.com.
Is this what you purchased? Did you buy the adjustable one?
 

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Can I ask how this corrected the issue? Did it change the angle of the assembly?
The part increases the length of the linkage by about 75% while still achieving full throw.
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Discussion Starter #11
The Sniper out of the box really sucks for the linkage. Not sure what they were thinking. I installed the progressive linkage (opens 2 BBL first then eventually all 4 BBL). It is like night and day for actually using it. I only have a few miles on my car but very driveable.

I bought my parts at EFISystemPro.com.
What do you think about this as a solution?
 

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Discussion Starter #12
The part increases the length of the linkage by about 75% while still achieving full throw. View attachment 750886
What do you think about this as a solution?
 

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The throttle lever on the 2bbl is virtually the same as the 4bbl.
 

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Forgive my lack of knowledge here but this added part doesnt look like it changes the distance of anything (before vs after pic)? Am I missing something? Whats the meaning of bolting this piece on?
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1587135136755.png
 

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The progressive linkage delays the secondary ports of the 4bbl from opening until afterr the primaries have begun to open. You do not have secondaries and therefore will not have the benefits that the linkage can offer.
The linkage in the second image you posted does the same thing as my solution!
 

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Discussion Starter #16
The progressive linkage delays the secondary ports of the 4bbl from opening until after the primaries have begun to open. You do not have secondaries and therefore will not have the benefits that the linkage can offer.
The linkage in the second image you posted does the same thing as my solution!
Im not understanding he difference from picture 1 and 2 I posted how this makes a difference? Is everything not connected in picture 2 because I just see that piece added on but nothing looks to have changed with the angle. Think its worth purchasing to try?
 

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Forgive my lack of knowledge here but this added part doesnt look like it changes the distance of anything (before vs after pic)? Am I missing something? Whats the meaning of bolting this piece on?
View attachment 750887 View attachment 750887
If you look closely, you'll see it does move the attachment past the end of the original linkage. The upper nut/bolt is in the original linkage mounting hole.
 

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The two picts look like they are different scale so hard to see what is going on.
Looking at the top nut on the pict to the right, it looks like it goes into the hole shown on the top of the left linkage. The arm then provides an extension, which seems to be what you need.
 

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The blue line in each image represents the linkage from the pedal. The red line in each image represents the length of the stock throttle lever. The green line shows the "additional" length added to the lever.
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Is this what you purchased? Did you buy the adjustable one?

Sorry just realized you have 2 BBL version. Sounds like the 2BBL has the same "stiff" issues as the 4 BBL, so Rhutt I think has the solution for you.
 
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