1988 Allergo motorhome 454 timing.

Chuck

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Nov 24, 2006
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Location
Billings, MT
Make
Chevrolet
Model
Allegro motorhome
Year
1988
Miles
97,900
Engine
454
Hey everyone, I'm back. I was getting ready to adjust the timing on this motorhome and none of the marks line up. It also has 2 timing tabs. One at 1 o'clock ( I think) and another at 5 o'clock. When I shoot the light on it the timing mark is above the 1 o'clock tab completely. The engine is completely original. Is there something I'm missing or is the distributor clocked wrong, etc. ?
 

grcauto

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Can you take a picture of the timing tabs? I have the info but need to see what you have.
 

Mobile Dan

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You might have to disconnect the "timing connector" which stops the computer from advancing the timing. At that point the engine is running at "base timing" and the timing can be read and adjusted, if necessary. Best to try this with a warm engine...a cold engine may stall if you want it to idle at "base timing". "Where is the Timing Connector?", you ask.........Mobile Dan shrugs shoulders.
 

billr

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That connector should be an inline single-wire connector in the harness to the dizzy; within a few inches of the dizzy.
 

grcauto

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Are we sure the ignition timing is computer controlled?
I think this may have mechanical timing advance.
 

Chuck

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Are we sure the ignition timing is computer controlled?
I think this may have mechanical timing advance.
Sorry I didn't reply sooner. No the timing isn't computer controlled. I will take pictures as soon as I get home today.
 

billr

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Are you disconnecting the vacuum line to the dizzy while checking timing?
 

Chuck

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Hello again. Here are the pictures of the 2 timing tabs. Yes, I unplugged the vacuum line from the distributor and put a screw in the line.
 

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billr

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Why not just bring it up on #1 TDC and see which tab lines up with a mark on the damper?
 

grcauto

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I remember these being at the 2 o'clock position or there abouts. I don't see the lower one in your picture.
 

billr

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Well, I see two tabs in the RH picture but only one in the LH picture. Since we read/write left-to-right, I'm thinking the LH one is the "first" one.,,

Regardless, the pictures are not much help, except to show that the "2 o"clock" one is bent and needs to be recalibrated. Again, just put it on #1 TDC and find where the tab should be!
 

Chuck

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As far as I know I did. I only saw 1 and each time I tried lining it up it corresponded with the intake and exhaust stroke.
 

Chuck

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Location
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I pulled the distributor today and reclocked it pointing at cylinder one, then reassembled the cap and plug wires to the corresponding hookups on the cap. It started up faster than it used to. After it warmed up, I keep the vacuum line off and plugged and set the timing at 8 degrees BTDC according to the upper tab. It does run alot better and more responsive.
 
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