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PostPosted: Thu Jan 25, 2007 2:44 pm 
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2 BBL ''SuperSix''

Joined: Wed Dec 07, 2005 4:27 pm
Posts: 21
Location: honolulu, hawaii
Car Model:
hi guys.

here's the problem: when i turn the ignition, it revs a bit, then stops. doesn't even drop to idle before it dies.

a bit of work history on the engine: in july i had a really bad oil leak; the oil pan gasket was practically nonexistent, and oil was also pouring out of the crankshaft seal. we yanked the engine, and resealed all these areas, but since the engine was already out, we also did a few more things: new gaskets to the intake/exhaust manifolds; new timing chain, new timing chain cover gasket; new water pump gasket; hi-temp gasket sealer wherever applicable. there were also a few rusted out cracked studs on both ends of the intake (because the water passes behind the studs), which were retapped with slightly larger stainless studs before reattaching the manifolds. we added also a 2 barrel carb, and the super six intake/exhaust manifolds, and a homemade kickdown that we had pulled off another guy's car. the one thing we were worried about when putting the engine back together was that the rubber gasket between the outer and inner ring of the damper was brittle and cracking.

everything was working great when we test drove the car. lots of power, mileage was even really great (18 mpg!). car would start up after two pumps of the pedal. about a week later, it started to become difficult to start up the car. 3, 4, 8 pumps, or more, and occasionally it would start up on 2 if i held down the pedal to the floor. mileage went down, power went down, and occasionally whenever i tried to accelerate, it would stutter.

a few weeks ago, it started to run extremely rough. it would always sound like it would die on idle, and occasionally would die. as i was extremely busy with work, i didn't have time to mess with the car. the only thing i really did was adjust the throttle cable to idle higher. seemed to work for awhile, but i went to my friend who helps me with my car sometimes, and he thought that maybe it was a vacuum leak. we checked the bolts on the manifolds. one on the edge was loose, and there was a black streak coming out from that area. we tightened up the bolt.

about a week ago, the car started to exhibit the problem as i first described it. won't even idle, won't even let me rev it. it just dies. thinking it was a carb problem i switched out to another carb that we knew was working on another car. same problem. i marked inner and outer ring of the damper but the car won't even run long enough to tell if the rings are shifting and the timing is getting off.

does anyone have any ideas? i'm a bit at a loss.


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 Post subject: Vaccuum leak?
PostPosted: Thu Jan 25, 2007 4:39 pm 
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Joined: Tue Oct 29, 2002 8:27 pm
Posts: 9714
Location: Salem, OR
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Sure sounds like you aren't getting enough fuel, or there is a place some nice air is getting into your setup...basically, instead of just tightening...you should have your buddy spray around the manifold set with some carb cleaner/ether/etc...(I prefer carb cleaner)...if he sprays an area and it stays running you have a leak there (or if it's running and the idle suddenly gets better...bingo)...

You may also find your carb base gasket may be a bit old and letting in some un metered air too...the spray will tell.

If it's more than one place on your manifold, it may be time to pull it and have it planed at a machine shop so you know it's "flat".

good luck,

-D.Idiot


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PostPosted: Thu Jan 25, 2007 5:06 pm 
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Joined: Tue Jun 27, 2006 8:21 am
Posts: 1614
Location: Orlando, FL
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I ve heard of the balast resister causing this starts then stops condition. But I have never heard it cause a rough running condition. Maybe if the resister was not open but a very high resistant and causing very weak spark?

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PostPosted: Thu Jan 25, 2007 5:30 pm 
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Joined: Mon Oct 14, 2002 4:32 pm
Posts: 4880
Location: Working in Silicon Valley, USA
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It sounds like a fuel problem.
If so, you need to figure-out if it is getting to much fuel or not enough.
Does it start faster if you prime it with a little fuel and shut the choke flap?
DD


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PostPosted: Thu Jan 25, 2007 6:19 pm 
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Turbo EFI
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Joined: Tue Feb 22, 2005 5:35 pm
Posts: 1044
Location: Maine
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My 68 Dart had the exact symptoms you are describing... Turned out that the points had slipped out of adjustment somehow and there was just a very, very tiny gap when they were open. Adjusted the points, ran perfect.

-Mac


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 Post subject:
PostPosted: Mon Jan 29, 2007 7:46 pm 
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2 BBL ''SuperSix''

Joined: Wed Dec 07, 2005 4:27 pm
Posts: 21
Location: honolulu, hawaii
Car Model:
no points. electronic ignition w/ MSD box & coil...

and both carbs seems to squirt out the right amount of fuel into the intake.

it was be really difficult to test the vaccuum leak now, as the car doesn't run long enough to test anything. :(


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 Post subject:
PostPosted: Mon Jan 29, 2007 8:25 pm 
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Joined: Thu Oct 31, 2002 5:39 pm
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Location: North America
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Quote:
I ve heard of the balast resister causing this starts then stops condition.
Not quite, no. A dead ballast resistor causes the engine to fire and run as long as the key is held in the 'start' position, but stall as soon as the key is released to 'run'.
Quote:
Maybe if the resister was not open but a very high resistant and causing very weak spark?
This condition usually is not found.

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 Post subject:
PostPosted: Tue Jan 30, 2007 3:57 am 
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2 BBL ''SuperSix''

Joined: Wed Dec 07, 2005 4:27 pm
Posts: 21
Location: honolulu, hawaii
Car Model:
Quote:
It sounds like a fuel problem.
If so, you need to figure-out if it is getting to much fuel or not enough.
Does it start faster if you prime it with a little fuel and shut the choke flap?
DD
if by shutting the choke flap u mean holding the pedal down to the floor — yes. 2 pumps on the pedal, and on the third, held the pedal to the floor for 10 sec. on ignition, turn key while holding the pedal down halfway. typically it does start faster, but it almost always ran rough and died.


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