Author Topic: Trouble kepping truck running after rebuild  (Read 5814 times)

Offline stevieray36

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Trouble kepping truck running after rebuild
« on: July 30, 2007, 07:43:51 am »
We just rebuilt a 1982 350 for my son-in-law's pickup and are having trouble getting it to run properly. We positioned the #1 piston TDC and installed distributor at proper location, turned flywheel until oil pump engaged and rechecked distributor location. Truck will only run with distributor rotated as far counterclockwise as possible "towards center of intake. When it runs its seems sluggish engine requires you to raise rpms to keep running. I dont know if it makes much difference but we are trying to get running with open headers,once its running we were going to complete exhaust.

We then pulled the distributor and tried to move "one tooth" counter clockwise and it will not start just backfires shooting flames out end of headers.

To position distributor in center of adjustment should we have rotated "one tooth" clockwise  from original position were it would start?

I wonder if we are having carb issues? The carb was working prior to the rebuild.

Offline ccz145a

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Re: Trouble kepping truck running after rebuild
« Reply #1 on: July 30, 2007, 09:05:16 am »
Ensure that you have the distributor just as described in your first description, then pick it up and rotate it 180 degrees. The piston reaches tdc twice in the cycle.

good luck!
1975 C10 Silverado LWB, 454CID, TH400, 10bolt 3.42
11MPG Downhill w/tailwind (but there ain't no hills here)

Offline 123 pugsy

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Re: Trouble kepping truck running after rebuild
« Reply #2 on: July 30, 2007, 09:11:43 am »
Are you sure you had #1 on the power stroke. Remember the crank goes around twice to the camshafts 1 rotation. Make sure both valves are closed when you find TDC. You should be able to turn the crank back and forth a bit and the rocker arms won't move when you are in the proper position. Then drop the distributor in and line up to # 1. Make sure the distributor can rotate both directions equally from the #1 position so you have no problem with timing.

The open headers won't cause a problem. It sounds like a timing issue.
Pugsy
76 C10 LWB
TPI 350

Offline Lt.Del

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Re: Trouble kepping truck running after rebuild
« Reply #3 on: July 30, 2007, 07:30:04 pm »
I agree...it is a common mistake....a 50/50 shot....you are firing the #1 cylinder on the exhaust stroke--the #6 cylinder should be firing when #1 is TDC on exhaust stroke. 180 degrees off.   Been there, done that.



Online VileZambonie

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Re: Trouble kepping truck running after rebuild
« Reply #4 on: July 31, 2007, 06:35:56 am »
I don't think he's out 180° - sounds like you're off a tooth and need to adjust the timing. Make sure the advance is working properly
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Offline stevieray36

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Re: Trouble kepping truck running after rebuild
« Reply #5 on: July 31, 2007, 09:55:23 am »
Vial, how much rotation in the distributor per tooth, is it equivalent to the distributor cap spacing? I tried to move "one tooth" and it appeared to move about the same distance as the post on the distributor cap. I believe I moved it "one tooth" in the wrong direction.

Online VileZambonie

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Re: Trouble kepping truck running after rebuild
« Reply #6 on: July 31, 2007, 10:06:28 am »
Just lightly pick it up and pay attention to distributor poistion and rotor position. On TDCC pointing at the terminal #1 in the cap the vac advance should also be just inward from the back corner of the valve cover. You'll get it right.
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Offline stevieray36

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Re: Trouble kepping truck running after rebuild
« Reply #7 on: August 02, 2007, 09:40:18 am »
We got it running, it will not idle but we will work on that. I initially rotated the distributor one toothe in the wrong direction.

Offline stevieray36

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Re: Trouble kepping truck running after rebuild
« Reply #8 on: August 02, 2007, 02:01:46 pm »
Were should the vacuum supply for the distributor come from? The manifold tee, thermostatic manifold tee, or the carburetor?

Online VileZambonie

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Re: Trouble kepping truck running after rebuild
« Reply #9 on: August 02, 2007, 03:00:32 pm »
You can hook it directly to manifold vacuum if you want which may seriously help improve your idle quality or you can hook it to a ported vacuum tap at the carburetor. Did you set the timing with a timing light?
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              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10