Re: Holley question - Idle
[Re: 68Bullit]
#138179
10/23/08 08:55 PM
10/23/08 08:55 PM
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Joined: Jul 2007
Posts: 531 Virginia
JimG
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Quote:
And if this Holley is burning excessively rich at idle, would that have a negative effect on the fuel economy as well?
heck yeah!
OK, we're back where we started with the Holley...which was checking your timing and being sure that retarded ignition timing wasn't causing excessive curb idle throttle plate opening...
Check the timing and let's be sure that's where it should be before we decide the carb is the culprit.
Jim
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Re: Holley question - Idle
[Re: JimG]
#138180
10/23/08 09:19 PM
10/23/08 09:19 PM
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Joined: Mar 2008
Posts: 571 Western NC
68Bullit
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Okay. Haven't put a light on there yet, but I'm almost certain the timing is good. I know that it HAS been advanced, just after it's recent build, and about every other time when starting the engine, there is a little clunk in there (slow skip for a lack of better description), that indicates the timing has been advanced. If I don't put the light on there now, what's the next step? OR, am I hearing that I need to put the light on there anyway? If so, I gotta order one.
Last edited by 68Bullit; 10/23/08 09:31 PM.
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Re: Holley question - Idle
[Re: JimG]
#138184
10/28/08 01:28 PM
10/28/08 01:28 PM
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Anonymous
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Anonymous
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Quote:
Bullit;
It might seem like a pain, but doing things out of order, or taking something for granted can send you down the wrong path and waste lots of time and money. Please resist the urge to assume anything! Almost everyone on this board who has EVER had their hands dirty working on a car can tell you their tale of woe that resulted from taking a shortcut. Heck, I've got plenty of those stories myself!
Just remember that sometimes, the cure to the problem you're describing is drilling holes in the throttle plates of your carb. Drilling holes that you cannot easily undrill is the very last resort - we need to be sure the basics are coverd first. Hence checking the timing and knowing what you've got.
Do you have any "car buddies" from whom you can borrow a timing light? If not, look on eBay. You don't need anything fancy due to the fact that you have a timing tape installed. A used timing light will be more than sufficient.
Did you ever try screwing the idle mixture screws in to see if the engine would stumble or stall from a lean misfire? If it will, that's a good indication that you can get rid of some of the excessive rich condition with idle mixture adjustment. If not, it's yet another indication that the throttle plates are too far open at idle.
The previous poster gave you some good info for timing setup.
Does that AED carb have 4 idle misture screws or 2?
Jim
CHECK YOUR TIMING. You probably dont have what you think you have OR what you need- ESPECIALLY IF ITS A STOCK DISTRIBUTOR
With the timing advancedto 17 degrees at idle wit hte total at 34 or so, you'll have better idle quality cause your odle speed would have picked up- allowing you to close down the idle screw and throttle plates a bit. that gives you better control over the mixture.
Trust me, Im going through the same thing right now (see my post about epoxying mechical advance slots). I had a rich idle too. timing was SUPER LOW. I adjust it higher, idle speed picked up allowing me to slow it down by closing the throttle a bit. now the mixture screws work and idle is better.
The slot adjustment I just did on the advance plate will allow me to set the initial where I need it and still have the total advance I want (without going TOO HIGH).
my distributor fooled me. it fooled me for about a month or so as I was getting this motor togehter..... CHECK IT
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Re: Holley question - Idle
#138185
10/28/08 02:10 PM
10/28/08 02:10 PM
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Joined: Mar 2008
Posts: 571 Western NC
68Bullit
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Thanks Guys. Looking at a couple of timing lights now. I know for sure the timing has been advanced but I still need to know the numbers anyway, and for future use, etc. BTW, currently using an MSD distributor with 8mm plug wires, and a MP electronic box. Should have a light shipped to me within a couple of days.
Last edited by 68Bullit; 10/28/08 02:12 PM.
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Re: Holley question - Idle
[Re: moparmarks]
#138187
10/29/08 06:43 PM
10/29/08 06:43 PM
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Joined: Mar 2008
Posts: 571 Western NC
68Bullit
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Quote:
Like said above, get the time set first. Timing is set at 800rpm. Is the carb new? Rebuilt? Used? Is an older style or newer? Does the A/F screws make a difference when turned in?
Update. Okay. Still waiting on the timing light. Just recently started the car and tried turning the A/F screws and it DID affect the idle of the car. After turning in the screws just 1/4 turn each (all 4 of them), the rpms went waaay down and the engine would stall.
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Re: Holley question - Idle
[Re: 68Bullit]
#138188
10/29/08 08:15 PM
10/29/08 08:15 PM
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Joined: Jul 2007
Posts: 531 Virginia
JimG
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Quote:
Just recently started the car and tried turning the A/F screws and it DID affect the idle of the car. After turning in the screws just 1/4 turn each (all 4 of them), the rpms went waaay down and the engine would stall.
OK, that's good.
Your entire problem might just be the idle mixture set up too rich. If you can turn any of those 4 screws in (clockwise) and not negatively affect the idle quality of your engine, you've probably helped the situation.
Go around to all 4 screws (after the engine is fully warmed up, and if you don't have intake manifold heat we could be talking 20-30 minutes) and try turning each idle mixture screw in, maybe 1/8 revolution or less at a time, then stop and give the engine time to respond. Blip the throttle now and then. As soon as the engine begins to stumble, you went a little too far with that particular screw. Back it out to the last spot where the engine idled OK, then move on to the next screw.
What I'm trying to get you to do is set the idle mixture at the leanest possible setting where you still have acceptable idle. If you do the above and still have that rich carb stench, it's a sign we need to look elsewhere for the problem.
Still check the timing when the light comes in and let us know what's going on. In the meantime, doing the above won't hurt a thing.
Jim
ETA: You know, no one has mentioned the float levels. Duh! Have you checked them?
Last edited by JimG; 10/29/08 08:19 PM.
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Re: Holley question - Idle
[Re: JimG]
#138189
10/29/08 09:53 PM
10/29/08 09:53 PM
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Posts: 571 Western NC
68Bullit
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Quote:
ETA: You know, no one has mentioned the float levels. Duh! Have you checked them?
Yeah, both levels appeared okay as far as I know. I checked them on level ground and fuel appeared to be level with the bottom of the sight opening for the FRONT, and then SOME (very little oozing) from the REAR float bowl sight opening once the screw was removed. Sound good?
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Re: Holley question - Idle
[Re: 68Bullit]
#138190
10/30/08 07:56 AM
10/30/08 07:56 AM
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Joined: Jul 2007
Posts: 531 Virginia
JimG
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Quote:
I checked them on level ground and fuel appeared to be level with the bottom of the sight opening for the FRONT, and then SOME (very little oozing) from the REAR float bowl sight opening once the screw was removed. Sound good?
Yeah, sounds good! I was worried that the levels were way high, but you're OK.
OK, back to the idle mixture screws.
Jim
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Re: Holley question - Idle
[Re: JimG]
#138191
10/31/08 04:17 PM
10/31/08 04:17 PM
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Joined: Mar 2008
Posts: 571 Western NC
68Bullit
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Quote:
Hello Bullit.
Yes, just check it in park. Be sure to disconnect the vacuum advance, if it's connected.
If you reconnect the vacuum advance and the timing advances at idle (assuming it's plugged into ported vacuum, on the passenger side of the primary metering block), that's another clue that the throttle plates are too far open at idle.
Nothing is hooked into my carb except a PCV from both valve covers. I have a T-fitting to accept both hoses from the valve covers and it is routed into the single fitting at the back of the carb. The carb is a mechanical secondary. When I check the timing, Do I just unhook the hose at the back (where both valves run into the carb)? Still waiting on the light but thought to ask about this anyway. Getting ready to go outside and check the A/F screws........
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Re: Holley question - Idle
[Re: 68Bullit]
#138192
10/31/08 04:20 PM
10/31/08 04:20 PM
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Anonymous
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well thats a problem. you are sucking from BOTH valve covers.... where is the inlet to the crankcase.
you want 1 PCV valve on one side valve cover and a breather on the other....
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Re: Holley question - Idle
#138193
10/31/08 04:27 PM
10/31/08 04:27 PM
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Joined: Mar 2008
Posts: 571 Western NC
68Bullit
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Quote:
well thats a problem. you are sucking from BOTH valve covers.... where is the inlet to the crankcase.
you want 1 PCV valve on one side valve cover and a breather on the other....
I've done both. Had the PCV on the passenger side with a breather on the driver's side, then just recently hooked up both PCV's. I can set it back to the PCV/breather setup, but it's really rich either way. BTW, the only reason I did both PCV's was because the breather was putting out a little bit of smoke.
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Re: Holley question - Idle
[Re: 68Bullit]
#138194
10/31/08 04:54 PM
10/31/08 04:54 PM
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Anonymous
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Anonymous
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put the pcv on the side opposite the fill cap.make sure there is suction at the pcv, else find out why. make sure the vlave cover is tight.
to check the pcv system, let the car idle with pcv in VC. remove breather and hold a stiff piece of paper up against the grommet. it should be sucked up against it (albeit lightly). if it doesnt, you dont have enough vacuum or too much blowby or the oil fil or VC is leaky
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