Re: Idle speed changing, what would cause this?
[Re: KnuckleDuster]
#1786064
03/22/15 10:35 PM
03/22/15 10:35 PM
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Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
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I would clamp the PCV hose and PB hose with vice grips with a rag to protect the hose from the serrations & retry it just to elim those vac leak potentials. got another carb you can borrow/sub in for an hour to test? that would confirm/elim the carb but that'd be my guess (carb) expecially with it being P/T & that severe. Is the linkage hanging up anywhere?
live every 24 hour block of time like it's your last day on earth
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Re: Idle speed changing, what would cause this?
[Re: KnuckleDuster]
#1786067
03/23/15 01:30 PM
03/23/15 01:30 PM
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Joined: Dec 2009
Posts: 1,023 pa.
dan9
super stock
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super stock
Joined: Dec 2009
Posts: 1,023
pa.
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Re: Idle speed changing, what would cause this?
[Re: dynorad]
#1786070
03/23/15 08:18 PM
03/23/15 08:18 PM
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Joined: Jul 2005
Posts: 1,723 North Austin
KnuckleDuster
OP
top fuel
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OP
top fuel
Joined: Jul 2005
Posts: 1,723
North Austin
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Pretty much eliminated the possibility of vacuum leaks. It's surging about 100 rpm. Played with the mixture and timing. Couldn't get a good vacuum reading on it as I dont have an adapter to hook my mityvac to the 3/8 full manifold vacuum fittings. Thinking this mallory distributor is crap like Rick Ehrenberg says,timing is erratic. Frustrated...it was running strong enough to smoke the tires 150 yards yesterday,then it ran 230° on the way home and the idle jumped up when I got there.I have till Thursday night to figure this out, before a 2 hour trip to Ennis.
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Re: Idle speed changing, what would cause this?
[Re: KnuckleDuster]
#1786074
03/23/15 11:42 PM
03/23/15 11:42 PM
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Joined: Jan 2003
Posts: 15,829 Omaha Ne
TJP
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 15,829
Omaha Ne
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Quote:
Thinking this mallory distributor is crap like Rick Ehrenberg says,timing is erratic.
Frustrated...
Blaming the distributor manufacturer is like blaming anything that was not installed or applied correctly. IE: Holley, Carter, Edelbrock, Rochester, Carburetors are all Junk because I could not get it to work out of the box and someone agreed with me. When modifying things (installing aftermarket parts), to be successful it takes more than buying the part to understand how it will work in your application. There are a ton of variables involved none of which the manufacturer can be blamed for if the end user does not understand and adjust it to his application. NO Offense meant to you but if we are going to help solve the problem you are describing it may require some effort / learning on your part. STEP 1. Get a good timing light and find out if the advance "Curves" are stable below 1500-2000 RPM. (Both Vacuum and mechanical). I say this as this, IMO is your most likely candidate based on the description. Again not trying to be a smart a-- or offensive just HELPFUL. Once it is established that the advance curves are not bouncing around we can them move onto other possibilities.
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Re: Idle speed changing, what would cause this?
[Re: TJP]
#1786076
03/24/15 06:35 PM
03/24/15 06:35 PM
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Joined: Jul 2005
Posts: 1,723 North Austin
KnuckleDuster
OP
top fuel
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OP
top fuel
Joined: Jul 2005
Posts: 1,723
North Austin
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I swapped in a original Mopar distributor and tried timing with a vac guauge. Most I can get is about 10hg and its flickering an bouncing about 2hg. What should I be seeing on the light at 1000rpm idle in park? The best it ran was showing about 30° on my old Suntech light. Tightened the idle mixture screws to light bottom,came 1-1/2 turns out and started backing out 1/4 turn at a time on both sides looking for a vacuum change. Nothing noticeable. Having a hard time finding a spot where the idle does not drop in gear. Feeling pretty lost here. To top it off the trans, which I just paid a shop to reseal is leaking badly in the rear and either the pan or front seal, plus now my 8-3/4 is dripping too. Guess the car is not going this weekend. ...yeah I know, just not a good day. ...and no offense taken I come here to learn.
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Re: Idle speed changing, what would cause this?
[Re: KnuckleDuster]
#1786079
03/24/15 11:51 PM
03/24/15 11:51 PM
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Joined: Jan 2003
Posts: 15,829 Omaha Ne
TJP
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 15,829
Omaha Ne
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STEP One, Disconnect and plug the vacuum advance. Step Two, Check and verify what the timing is doing at or near idle. IE: Initial timing is just that and it should immediately return to the same setting when blipping the throttle. If it floats IE: slowly comes back down the mechanical advance inside the distributor is too loose and will drive you nuts while trying to establish a repeatable idle RPM. WHY??? Because the mechanical advance curve is not snapping back to its starting position. Hope this makes sense ?? Start with the basic steps 1 & 2 and report back
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Re: Idle speed changing, what would cause this?
[Re: KnuckleDuster]
#1786081
03/26/15 01:32 AM
03/26/15 01:32 AM
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Joined: Feb 2003
Posts: 10,294 Someplace you aren't
SomeCarGuy
I Live Here
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I Live Here
Joined: Feb 2003
Posts: 10,294
Someplace you aren't
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Disconnect the msd. Wouldnt be the first one of those to go on the fritz. Ive seen them cause strange issues multiple times.
I want my fair share
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