Thanks Neil!
What was the question ? :notsure: ( i was wondering about the hole in the throttle plate )
The question is, "What can I do to obtain my desired idle speed and maintain the function of the Idle adjustment needles?"
Google, or look in your Holley book, for detailed info :)
Quote from: Strawdawg on May 16, 2018, 03:09:36 PM
The question is, "What can I do to obtain my desired idle speed and maintain the function of the Idle adjustment needles?"
Google, or look in your Holley book, for detailed info :)
When I spoke with Neil today we discussed the problem I am having with the idle fuel adjustment screws and what I can do short of
a new carb.
Quote from: 71-440 on May 16, 2018, 04:21:58 PM
Quote from: Strawdawg on May 16, 2018, 03:09:36 PM
The question is, "What can I do to obtain my desired idle speed and maintain the function of the Idle adjustment needles?"
Google, or look in your Holley book, for detailed info :)
When I spoke with Neil today we discussed the problem I am having with the idle fuel adjustment screws and what I can do short of
a new carb.
Ok. But what is the hole in the throttle plate for? Thanks.
Quote from: GY3R/T on May 16, 2018, 05:57:21 PM
Quote from: 71-440 on May 16, 2018, 04:21:58 PM
Quote from: Strawdawg on May 16, 2018, 03:09:36 PM
The question is, "What can I do to obtain my desired idle speed and maintain the function of the Idle adjustment needles?"
Google, or look in your Holley book, for detailed info :)
When I spoke with Neil today we discussed the problem I am having with the idle fuel adjustment screws and what I can do short of
a new carb.
Ok. But what is the hole in the throttle plate for? Thanks.
Lets in air so it will idle on engines producing low vacuum
Exactly Steve , Thanks :bradsthumb:
the problem with low vacuum engines is you have to open the throttle a lot to keep the engine running , in some cases you have to open it so much that the idle circuit no longer works & you end up idling at 1500 rpm off the main jets , by drilling a hole you can get enough air into the engine without uncovering the idle transfer slots & usually create a decent idle around 850-900 rpm & the idle slots still work .
I actually had answered in more detail but I hit something by accident and it all disappeared. LOL
It is all good !
Great to see you here too :bigthumb:
I'm glad to still be able to be seen :) Usually, when I read the new posts, a bunch of people have already replied so I don't add another 2 cents :)
I have been playing with Holleys on and off since the '60's and, to me, they are the most logical carbs out there. With a couple fo the better books, they are really easy to understand and work on.
I agree although the Proforms are more adjustable for a lower price .
we are getting into tuning season so hopefully there will be a lot more posts like this to get our teeth into !! :woohoo:
yes, I should have said Holley style...:)
Quote from: Chryco Psycho on May 16, 2018, 08:23:00 PM
I agree although the Proforms are more adjustable for a lower price .
we are getting into tuning season so hopefully there will be a lot more posts like this to get our teeth into !! :woohoo:
Sounds like an invitation, so here goes.
Have a SB360 with mild 340 like cam. Recently swapped out the 600 edelbrock for a brand new 670 Proform, vac sec, 4 corner idle. Straight out of the box I could not screw the idle speed screw below 1400rpm, it ran out of adjustment at that idle speed. Ok, I thought, I'll adjust the idle mixture screws & then reset idle speed. Ended up with all 4 corners about 1 1/4 turns out but idle at 1700rpm, no good. Grabbed trusty vac gauge & reset mixtures to highest vac reading ~17-19hg, still cannot turn idle down below 1600. Finally pulled carb off & checked transition slot in 2ndary barrels & was correct (square shape ~.025" showing). Replaced carb & tried again, only way to get idle below 1000rpm was to uncover more transition slot which then results in only front 2 idle mixture screws having any (minimal) effect, & richening mix until black smoke stinging my eyes. Read up on internet about power valve symptoms, haha I thought I had it solved, but $25 later no different. As it runs now, it will idle at around 850 rpm, light acceleration from idle flutters & dies without more acceleration & then at speed a giant bog on W.o.t before it opens up & takes off. This thing is doing my head in I'm ready to throw it in the bin & go back to the eddy, although that had a sloppy primary shaft, it ran reasonably well & would idle right down to 550-700rpm no problem. Timing is set at 14* initial, not sure on max,36 maybe ? with vac can disconnected (plugged). Plugs are black, black, black all the way around. One thing I did note on carb arrival it was missing a base gskt & the proform decals on the fuel bowls say "650" not 670 as per the box, maybe a shop return that someone had played around with ? It's a bit hard to return this stuff when you've gotta ship it back across the pacific at own cost. That's where I'm at, anyone have a magic bullet ? Seriously appreciate any input that might help.
Normally, when one refuses to idle down, I think of a large air leak. It could be between the base and the body, or the metering blocks are not sealing to the body due to loose bowl bolts, bad gaskets, or warpage from over tightening. And, the simplest of all, the manifold vacuum port is not capped off when the vacuum advance is disconnected :) Some insist on capping the wrong end of the tube....
In your case, it almost sounds like the idle circuits are not supplying any fuel and you are having to open the blades and run it off the main circuit. I am wondering if one of the passages was not drilled all the way thru or one of the idle fuel tubes has some debris in it? You may try blowing some carb cleaner thru the various passages and see if it comes out on the other side.
Something seems contradictory in your description but I have learned that sometimes things are contradictory and it makes troubleshooting even more fun.
I would not be surprised if you got a returned carb altho they normally should smell like gas when you get one...
How long ago did you buy it ?
Can you return it , sounds like someone bought it swapped the carb & returned it with a bad carb in place as it is not marked correctly , who know what might have been messed with internally !
Chryco Psycho. Are you saying to add these holes on low vacume engines or to enlarge the hole?
Because most (if not all) of my holleys have that hole on primary throttle plates from factory,even two BBL's.
if you cannot get the idle working correctly you may have to add or enlarge the holes , not all carbs have them
Quote from: Strawdawg on May 17, 2018, 05:59:11 AM
Normally, when one refuses to idle down, I think of a large air leak. It could be between the base and the body, or the metering blocks are not sealing to the body due to loose bowl bolts, bad gaskets, or warpage from over tightening. And, the simplest of all, the manifold vacuum port is not capped off when the vacuum advance is disconnected :) Some insist on capping the wrong end of the tube....
In your case, it almost sounds like the idle circuits are not supplying any fuel and you are having to open the blades and run it off the main circuit. I am wondering if one of the passages was not drilled all the way thru or one of the idle fuel tubes has some debris in it? You may try blowing some carb cleaner thru the various passages and see if it comes out on the other side.
Something seems contradictory in your description but I have learned that sometimes things are contradictory and it makes troubleshooting even more fun.
I would not be surprised if you got a returned carb altho they normally should smell like gas when you get one...
Thanks for reply Strawdog,
I thought vac leak as well, but half a can of aerostart sprayed all over top end says otherwise. I did remove the bowls & blow air through all the holes in both metering blocks, replaced power valve & checked both base gskts for obvious leaks (carb sits on phenolic spacer). Even did leakdown test on brake booster & changed pcv valve, no evidence of leaks. Is 17-19hg of vacuum at idle too high ? Cam is very mild so would expect similar to stock vac number.
@Chryco Psycho (https://forum.e-bodies.org/mlist/chryco-psycho_4), probably too late for return now as I've had carb over 6 months. I did contact the seller about the anomalous decals on the bowls, but he responded that it was probably just a Proform error, nothing to worry about.
Might revert to the eddy, just a lot more sluggish up top, but no bog or idle issues. :dunno:
I would check directly with Proform , you should have a 1 year warranty , customer service might look after you
19" is good.My guess is a plugged idle fuel passage, but guesses are worth what you pay for them and I would be afraid to charge for this one.
I think Neil is correct, contact Proform directly and pray
I suspect if you had another one to try, it would work fine
Thanks for the input guys.
cheers.....
Steve.
I lived in Australia for a couple of years long ago and I have never understood why it is relatively cheap to mail/ship stuff out of Hong Kong, China, etc without much hassle, but, getting stuff in and out of Australia is such a bummer.
Yeah it can be painful, especially with the $AU bottoming out against $US.
Luckily I bought the car at about 96c to the dollar in 2014, I wouldn't wanna do it now.