Holley Sniper adjustments (1 Viewer)

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I did the desmog and added the Holley Sniper. I made some minor adjustments but haven't gotten in detail yet with the programming so it's pretty much out of the box as far as set up. I am getting pre detonation with whatever fuel type I run when I lug the motor. I have the stock dizzy, wires and ignition coil. So I am considering upgrading these things before I go any further however I really don't want to if I don't have to.

I haven't checked the timing yet either that is on the bucket list. Do you think that a timing adjustment and adjustment to the Sniper can fix these problems or will I just be beating my head off the wall without the other upgrades. ?

Thank you !
 
I suspect you need to recurve your dizzy to account for the lack of EGR, but I'm not sure how much impact that would have on an EFI conversion.

I actually need to ship my dizzy off to Jim to be recurved for my EFI build.
 
If your ignition is completely stock and you did a full desmog and you are getting pinging:

1: verify your base timing is set to to 7 deg btdc
2: try swapping the two vacuum on the vacuum advance.
3: because you removed the EGR you will likely need to have the dizzy recurved.
 
I suspect you need to recurve your dizzy to account for the lack of EGR, but I'm not sure how much impact that would have on an EFI conversion.

I actually need to ship my dizzy off to Jim to be recurved for my EFI build.

efi cannot compensate for ignition problems.
 
For now, put in 91 octane and retard your timing a couple degrees at a time until it stops. If I remember right, you want to use the inner port on the distributor.
 
For now, put in 91 octane and retard your timing a couple degrees at a time until it stops. If I remember right, you want to use the inner port on the distributor.
Yes inner port . I’ll check timing later today . I’ve been using 92 it helps a little . Also tried ethanol free that didn’t help
 
It feels good to free yourself from all the excess plumbing. How is your start up and idle? The turn around on a recurve is a couple months unless you DIY. You might want to get a DUI HEI, or non-smog dizzy for the meantime.
 
It feels good to free yourself from all the excess plumbing. How is your start up and idle? The turn around on a recurve is a couple months unless you DIY. You might want to get a DUI HEI, or non-smog dizzy for the meantime.
It starts right up and idles fine . It’s in the high side 850rpm but I think that’s a minor adjustment
 
It starts right up and idles fine . It’s in the high side 850rpm but I think that’s a minor adjustment
I settled for 750rpm. I had it at 650 but had stalling issues when engine braking before a stop. It still stumbles in that situation until it's coolant temp is about 180°. I need more tuning but have a valve or compression issue I need to get sorted first.
I'd be curious to see everyone's tuning numbers.
 
Setting time on these seems a little different than I'm used to and I haven't used a timing light in 20 years... lol Is there a good guide on here start to finish ??
 
It's on the flywheel, passenger side. There should be a shutter held on by a single bolt.
On the flywheel, there is a line for TDC and a divot (called a beebee). The beebee is 7° before TDC. It should be on the money. Mark it with some white paint. Your new timing mark will likely be somewhere between TDC and the beebee.
 
Oh! Disconnect the vacuum hose. You need need to set your idle down to 700 or less so the centrifugal advance isn't giving you a false reading.

(Something you should know: the advance limiter in your dissy had a plastic cap that likely disintegrated allowing you to get too much advance, hence the pinging)
 
7416D08F-A448-4755-AD7D-BD8DEF22C3C4.jpeg

Just painted mine actually, so if you need a photo reference, here is timing mark and bb.
 

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