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The Big Money
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Discussion Starter · #1 ·
Got a problem with my 89 Silverado. When I go to stomp on the gas it bogs like an outboard motor and doedn't give me full power. In first gear its ok, in second it gets a little worse and in third its just wants to die. Checked the timing and its at 32 degrees, replaced the plugs, checked both fuel filters and fuel bowls in the carb. There is plenty of fuel pressure on the gauges, in neutral there isn't much of a problem its just when its under load

Here is the rundown on my engine:

1970 350 block (no computer)
12:1 compression
solid lifter cam
Holley 750 DP
Full MSD Ignition
Turbo 400 tranny
10" 4000 stall


Thanks in advance
 

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Sounds like a classic case of running out of gas...................if you have good fuel pressure, it's got to be in the carb...plugged up, floats too low,
 

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The Big Money
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Discussion Starter · #3 ·
Fuel bowl levels are fine and I can see the fuel level from the sight plugs. What do you mean by plugged up?

Squirters are fine and there is nothing stuck in the jets (had that happen once)
 

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The Big Money
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Discussion Starter · #7 ·
I'm not too mechanically smart. Sometimes I think I am

When I point the timing gun at the harmonic balancer it flashes at 30-32 degrees on the timing tape when it is idling
 

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Well, if you really have 30-32* of timing at idle that could cause some problems. Do have your vacuum advance hooked to full manifold vacuum or ported? If its hooked to manifold vacuum thats why your timing is at 30 at idle, if not you have a problem. Take the distributor cap and rotor off and check to make sure the advance springs havent broken or came off. Ive also seen the wieghts so rusted and full of gunk that they got stuck at or near full advance.
 

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timing problem

You should be running about 8-10 degrees initial advance. Loosen your distributor hold clamp, and with the timing light on, retard the distributor by turning it clockwise, til you get back down to 8-10 degrees initial advance. Disconnect your vacuum advance hose first, and put a small plug in the hose, so you dont have a vacuum leak.

After you get the initial advance set, then rehook the hose and see what you have. If your advance jumps up a lot, that indicates you have your vacuum hooked to the wrong port. there is a metered vacuum port on your carburetor for hooking the distributor to. The metered vacuum port should be on the right side of your carb, toward the front.

On some models it will be sticking out of the base plate and on others it will be sticking out of the metering block, just above the idle mixture screw.

If that doesnt work, then we can persue other avenues.

With 32 degrees initial advance, I am surprised you can get the engine to turn over with any speed. With that much advance it should want to act like you have a near dead battery, when you try to turn it over.
 

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The Big Money
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Discussion Starter · #11 ·
nitrous383 said:
Well, if you really have 30-32* of timing at idle that could cause some problems. Do have your vacuum advance hooked to full manifold vacuum or ported? If its hooked to manifold vacuum thats why your timing is at 30 at idle, if not you have a problem. Take the distributor cap and rotor off and check to make sure the advance springs havent broken or came off. Ive also seen the wieghts so rusted and full of gunk that they got stuck at or near full advance.
I have an MSD distributor and there is no vacuum advance on it. There are no vacuum hoses coming off my carb as they are capped off. I run a hose from my manifold vacuum to my power brake booster. I'll take the distributor cap off tomorrow and have a look. I think I have a vacuum leak between the carb and the manifold

Thanks again

Charlie
 

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timing

Kewl. Go loosen the clamp on your distributor, only enough that you can turn it, and with the timing light hooked up, start the engine, turn the distributor clockwise, which retards it, until you come up with 8-10 degrees initial advance.

Then tighten the clamp, and take it for a test drive.
 

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The Big Money
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Discussion Starter · #13 ·
I think I found why my truck was running bad. I found a hole in my intake right by where the carb mounts to the intake. Plugged it up with a little JB Weld and when its dry I'l set up my timming right
 
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