Sniper/stiff sticky pedal

[McChargue]

So I installed a sniper system and it's worked flawlessly since day one. I'm still trying to dial in a few things on it tuning wise, but all in all I'm happy with the results. It does have a stiff or sticky spot right off the bottom. It's kind of a pain in the neck to try and leave a light, or pull out into traffic smoothly. It doesn't seem to be sticky when the engine is shut off, and the return spring I have installed isn't a factor. So I am leaning towards the suction of the engine running is creating a vacumn against the butterflies? Anyone else have any sort of issues similar to this? The only other thing I've pondered is a geometry issue coming into play, I have a Windsor and with the increased deck height the angle of the linkage is slightly uphill from the firewall to the throttle body. I am running the stock throttle linkage system. I've learned to deal with it pretty well but it tends to piss my wife off when she drives it.

 

[DirtDonk]

Yeah, sticky pedals and responsive engines do not mix well!
I agree totally with either the geometry or throttle blades. Which linkage type are you using currently? Stock mechanical with the early bell-crank setup? Later with just a straight shot off the firewall? Cable operated?

How is the Sniper set up initially? Do they allow for a slightly open throttle blade at idle? Usually when an EFI throttle blade is all the way shut against the bore, it will stick for that initial moment. But it still idles because the idle-air bypass valve (IAB) takes care of that when applicable.
Not sure how the Sniper is set up, but if this is the issue then you should be able to open up the throttle just slightly and still have a normal idle.

Got pics you can share?

Paul

 

[bronconut73]

Oh man I moved away from that linkage arm a long time ago. Lokar makes a throttle cable that's practically a bolt-on, very few mods.

Like butter, Homie.

 

[rguest3]

BC Broncos makes a direct bolt-on Throttle Cable set-up that would probably cure your Problem.

 

[Broncobowsher]

The geometry can get weird. You really need the pull to be 45° either side of perpendicular. At half throttle, if you draw a line between the throttle shaft and the pivot the pull needs to be perpendicular. If that perpendicular point happens at ¾ throttle, tip in will be jumpy.

 

[blubuckaroo]

I've had several different carbs connected to our '77s factory carb linkage. Never an issue.
I can't see how FI would make a difference.
I'd say a photo is needed.

 

[bronkenn]

I've had several different carbs connected to our '77s factory carb linkage. Never an issue.
I can't see how FI would make a difference.
I'd say a photo is needed.

If the Sniper is like the Fitech then in takes a lot more effort to actuate the throttle than a carb.

 

[OX1]

If the Sniper is like the Fitech then in takes a lot more effort to actuate the throttle than a carb.

Why?..............

 

[bronkenn]

Why?..............

The built in spring Fitech put in there. Very heavy duty.

 

[JWMcCrary]

I found the same to be true with the Holley Terminator, installed in 2013. after a lot of different configurations I just decided to live with it. I ended up using a cut down kickdown cable for a C4 as throttle cable, works fine. No big deal after you get used to it. It's all a matter of duplicating the same tension as you had with a carb, which I gave up on. I have another bronco with a carb, when I get in it now it seems weird and too soft until I've driven for a few minutes and adjust myself for the feel.

 

[jwhit]

sniper fix

i had same problem with my sniper i swap to progressive linkage on sniper unit
you can buy the linkarm from summitt or other source then change settings on sniper unit to match i have my secondary real close to 40% before they open
this fixed my issue . fyi here is link to details

https://www.efisystempro.com/image/...justable-Progressive-Linkage-Instructions.pdf

 

[Broncobowsher]

Why?..............

The secondaries open in unison with the primaries. Each set of throttle blades has a return spring. That unison part also plays with tip in response since you are opening 4 throttles instead of just the primarys. When you get on the throttle hard enough to open the secondaries, the pedal gets a lot stiffer. But you never notice since you are just mashing it to the floor anyway.

 

[McChargue]

Thanks for all the ideas guys. I think I am going to chase that progressive linkage and also move towards a cable throttle instead of the bellcrank linkage. I'll post some results here after I get that all in place.

 

[Broncobowsher]

I really liked the progressive upgrade back on my old Projection 4-barrel.

I'm thinking about the Sniper Q-jet replacement. It is unique in the secondaries are progressive. They are like a normal carb in they don't start opening until ~75% throttle, then they open quick (and BIG). Saw one at the Holley booth at SEMA.

 

[AZ73]

Anyone got a Lokar part number for the Sniper and a Ford pedal? There seems to be a lot of choices.

 

[74 Bronco Billy]

i had same problem with my sniper i swap to progressive linkage on sniper unit
you can buy the linkarm from summitt or other source then change settings on sniper unit to match i have my secondary real close to 40% before they open
this fixed my issue . fyi here is link to details

https://www.efisystempro.com/image/...justable-Progressive-Linkage-Instructions.pdf

Exactly the type of remedy I was looking for, but no link on where to buy it? Or did I miss something?

Anyone got a Lokar part number for the Sniper and a Ford pedal? There seems to be a lot of choices.

X2

 

[AZ73]

Exactly the type of remedy I was looking for, but no link on where to buy it? Or did I miss something?




X2

i purchased the linkage kit from here. You have to chose the adjustable one from the right side pull down menu. They're back-ordered through mid Feb. Still looking for the correct Lokar

https://www.efisystempro.com/sniper/sniper-efi-system-components/sniper-efi-progressive-linkage-kit

 

[jwhit]

get the non adjustable link from summitt part #QFT-43-2QFT
you can bend yourself to adjust very easy i dialed mine in right at 40%
i have done this my sniper and a buddys who had same issue

 

[Broncobowsher]

OK, screw the Q-jet version. I'll be doing one of these. I almost have the Sniper on order. I just need to sell the tractor first.

 

[bknbronco]

so the sniper will work with a stock fuel tank?