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 Post subject: Wont idle in gear
PostPosted: Sat Mar 22, 2008 8:32 pm 
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2 BBL ''SuperSix''

Joined: Thu Apr 05, 2007 12:33 am
Posts: 14
Car Model:
Hello is have a 75 scamp my problem is when i put the car in gear it runs rough then dies and only does this when vehicle is at operating temp.

Here is a list of what i have done already.

Adjusted valves to spec
Replaced cap rotor wires plugs and pcv all with quality napa parts
Rebuilt the 1945 carb
Replaced the alternator and voltage regulator (fixed my low voltage problem at idle)
Replaced all vacuum lines and hooked vacuum advance straight to carb
I also checked engine vacuum and it was jumping rapidly from about 10-15

Any ideas or thoughts are welcome.


Last edited by 75scamp on Sun Mar 23, 2008 12:07 am, edited 1 time in total.

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 Post subject:
PostPosted: Sat Mar 22, 2008 8:54 pm 
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Supercharged
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Joined: Mon Jan 15, 2007 5:05 pm
Posts: 3767
Location: Black Diamond, WA
Car Model:
What is your timing set at?

If it is a zero degrees per spec that year, try 5 degrees. Sometimes you can run up to 10 with out recurving the distributor but you may need to adjust the vacuum can to compensate by turning it out 3 or 4 turns.

More initial should keep it running unless you have a massive vacuum leak in the carb. I finally had to retire my 1945 after several rebuilds because of this problem.

Tell us more.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG


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 Post subject:
PostPosted: Sun Mar 23, 2008 10:27 am 
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2 BBL ''SuperSix''

Joined: Thu Apr 05, 2007 12:33 am
Posts: 14
Car Model:
Any other ideas on this problem? could it be the distributor or coil?


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 Post subject:
PostPosted: Mon Mar 24, 2008 6:09 pm 
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2 BBL ''SuperSix''

Joined: Thu Apr 05, 2007 12:33 am
Posts: 14
Car Model:
Ok so i did some more testing and found that i only have 1.9v at the coil while running in park. What should it be at?


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 Post subject:
PostPosted: Mon Mar 24, 2008 7:25 pm 
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Supercharged

Joined: Sun Jun 04, 2006 4:53 pm
Posts: 4295
Location: Gaithersburg MD
Car Model:
It should register 7-8 volts at idle at the coil. You have found the symptom. Now you need to figure out why the voltage is low. Track the voltage from the alternator, through the firewall, and back out and see where it drops off. The alt should put out 13.5 at idle. Ignition switch, connectors, amp meter, voltage regulator? Check your gound and see if it is good. The high side of the ballast resister should read no less than .5 to 1 volt below the alternator. Even one volt drop is a sign of insipient problems.

Sam

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 Post subject:
PostPosted: Mon Mar 24, 2008 9:01 pm 
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Supercharged
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Joined: Mon Jan 15, 2007 5:05 pm
Posts: 3767
Location: Black Diamond, WA
Car Model:
The resistor mounted on the fire wall could be bad too. Some are not potted and will deteriorate faster or break. Try to find a new one that is potted on the back so you don't see the coils that is about 1 ohm, 1.5 ohms max.

Like Sam said you should have the same voltage at the input side of the resistor as the alternator output and about 7 to 8 volts on the other side of the resistor which is the output to the coil. So the output side and the coil should both read the same. If not you have some burned wires or bad connections.

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG


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 Post subject: Re: Wont idle in gear
PostPosted: Mon Mar 24, 2008 9:28 pm 
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Board Sponsor
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Joined: Tue Jun 27, 2006 8:21 am
Posts: 1614
Location: Orlando, FL
Car Model:
Quote:
I also checked engine vacuum and it was jumping rapidly from about 10-15
What does your vacuum do if you increase the rpm from idle to 1500 or 2000rpm? It sound like you've got ignition problems but something more to consider. If the vacuum smooths out, this could be a indication of worn valve guides. If it doesn't smooth out, broken or weak valve spring(s), or sticking valve(s). Or the ignition low voltage your finding.

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67Cuda,FAST EZEFI,340cu,CR=10.25,RollerCam&Rocker (XR268HR,#20-810-9)(#1622-16)(EddyRPM#60779,#7576), (MSD6AL,#6425) A904, GearVendorsOD, 8 1/4,3.55:1, ClassicAir
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 Post subject: Updated***
PostPosted: Sun Mar 30, 2008 4:11 pm 
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2 BBL ''SuperSix''

Joined: Thu Apr 05, 2007 12:33 am
Posts: 14
Car Model:
Well I fixed my problem with not idling in gear. It was the coil ,so i also installed a MSD 6AL and a msd coil man she runs smooth as ever accelerates well and runs smooth at stoplights. I can hardly believe its the same car.


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 Post subject:
PostPosted: Sun Mar 30, 2008 4:18 pm 
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Supercharged
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Joined: Mon Jan 15, 2007 5:05 pm
Posts: 3767
Location: Black Diamond, WA
Car Model:
Most excellent to news! Congrats :D

It's always nice to have a good flow of electrons!

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG


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