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Discussion Starter · #1 ·
I bought a 67 camaro and it has dual vacum secondary holleys on a high rise intake. I know my way around holleys, but am still new at it, and have no idea where to start with it.

Right now the thing runs terribly, and constantly backfires through the carbs. It will idle fine when warmed up, but has a pretty bad hesitation and still backfires through the carb if you nail it...I'm thinking I need larger accel pumps?

I know how to set the butterfly's on the primary butterflies, but don't know how I should set them on the secondary side.

Do both carbs need to be tuned the same, or does one have the be tuned different than the other.

How will I know how big of an accel pump I need to get?

It has an adj. fuel pressure regulator on there now and its set to ~9psi
 

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66 El Camino 57 Chevy pickup 2004 Tahoe
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dark,

posting the same question on multiple forums is spamming, please refrain.

9 lbs is too much, turn it down to 6 till you get stuff worked out. then you could bump it up to 7 if needed.

don't open the secondary butterflies at all. factory adjustment is to screw it in to contact plus 1/4 turn. Leave it there until unless it's necessary to change it.

Put the stock jets and PVs in both carbs. if the carbs have #28 accelerator pump shooters change them to 31 and buy 33 and 35 just in case.

If this is a tunnel ram you may end up needing to install 50cc pumps, but try to get it dialed in without those faucets first. THe problem with running TR on the street is that they were never meant for this, made to drag race at full throttle. Most likely by the time you get it fattened up enough to drive decently it will be so rich it will foul the plugs regularly, causing it to lay down and "shoot ducks" when you try to hammer it. In fact, it's doing that now, sounds like. Have you changed the spark plugs lately?
 

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Discussion Starter · #4 ·
dark,

posting the same question on multiple forums is spamming, please refrain.

9 lbs is too much, turn it down to 6 till you get stuff worked out. then you could bump it up to 7 if needed.

don't open the secondary butterflies at all. factory adjustment is to screw it in to contact plus 1/4 turn. Leave it there until unless it's necessary to change it.

Put the stock jets and PVs in both carbs. if the carbs have #28 accelerator pump shooters change them to 31 and buy 33 and 35 just in case.

If this is a tunnel ram you may end up needing to install 50cc pumps, but try to get it dialed in without those faucets first. THe problem with running TR on the street is that they were never meant for this, made to drag race at full throttle. Most likely by the time you get it fattened up enough to drive decently it will be so rich it will foul the plugs regularly, causing it to lay down and "shoot ducks" when you try to hammer it. In fact, it's doing that now, sounds like. Have you changed the spark plugs lately?
i just got the carbs identified and I do have a weiand tunnel ram. The carbs are

450cfm
mech secondary
single accel pump
31cc squirters
4160 series.

what do you mean by shooting ducks? Is that when you get a HUGE puff of smoke and a backfire out of the carbs when you rev quickly...cause its doing that.

as far as plugs go, I just bought this so I havent changed anything yet.

I went to adjust the fuel pressure and just tightened it a little bit, now the guage is at 0 and no matter how much I tighten/loosen the regulator it won't move :confused:

I'm going to tear into the carbs tommorow to figure out what size jets I have and see if the PV's are blown
 

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Sorry to tell you this but you're likely wasting your time. those carbs are not suitable for use on anything, especially a TR. with no secondary accelerator pump and mechanical opening it's always going to lean out and bog. I have no idea why the vendors would sell that setup as a kit, they never run right and would not be expected to.

Best idea? If you want to retain the TR buy a pair of #1850 vacuum secondary carbs. get the secondary vacuum diaphragm lids that have a tube sticking out the back so the secondaries can be equalized and install them.

Again, don't waste your time and energy trying to make that setup with those carbs work, it won't.
 
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