Timing issue on 86 gm 350

[Cmal7]

I am trying to set the timing on my 86k1500 it has a 350 and I can see the timing tab and the mark on the harmonic balancer but it barley runs and has no power at all if its set to 6-8 degrees advanced. It runs smooth and has normal power if the mark on the balancer is about an inch left of the timing tab when #1 is firing.. Which looks like its way advanced. Could this be right? Or was the harmonic balancer mark just out somehow? Thanks.

[grampadirt]

Are you setting the timing with the vacuum advance hose disconnected & plugged?Has the distributor been removed?Might have been reinstalled a tooth or two off.Is the #1 spark plug wire in the right hole on the cap?

[Cmal7]

Yes the vaccum advance is disconnected and plugged. #1 is installed to the right spot on thr distribbutor. I just bought the vehicle and yes the distributor could have been installed off one tooth off but why would that matter? Shouldn't the timing stay the same as long as it is corrected by rotating the cap to make up for the one tooth off?

[diyer2]

I think the distributor only goes in 2 ways, the right way and 180 degrees off.

If the dist. is 1 tooth off the timing mark on the harmonic balancer will be off.

You can check by removing #1 spark plug(remove coil wire) and turn it over so #1 piston is at top dead center, if everything is in time the timing mark will line up or be close.

[grampadirt]

You say it runs fine when you move the distributor it's just that it's not at the correct mark on the dampner...you ''corrected'' it.

 

Bare with me on this,if you would rotate the dampner to ''0'' at the pointer on the compression stroke.Remove the cap and take a pic of where the rotor is pointing.I know it's a pain but that's all I can think of at the moment.There are other members here that can help further.

 

 

lol,diyer2 beat me to it.

[Cmal7]

Ya that's right. If I set the timkng to a few degrees btdc according to the balancer mark and timing mark. it runs rough at about 5-650rpm and won't even respond to wot it almost stalls out. But if I advance the timing by rotating the distributor so far that the vaccum advance hits the fuel rail the idle smoothes out and Rpms increase to about 8-900. Rpm it responds to wot but if I look at the timing marks its way out. I will check the rotor position with #1 @ tdc that's a good idea. Thanks.

[Cmal7]

It's tough to get a pic that shows anything but with 1 @ ttdc and at 0 degrees on the timing marks the rotor is well past 1 on the distributor cap it's acctually about half way to the next plug to fire being 8 ... Does that sound like it has skipped a tooth?

[Cmal7]

It doesn't make sense to me why it would want to run so advanced... Shouldn't it run like crap? It's almost time to start replacing parts..

[desrtrat]

It's tough to get a pic that shows anything but with 1 @ ttdc and at 0 degrees on the timing marks the rotor is well past 1 on the distributor cap it's acctually about half way to the next plug to fire being 8 ... Does that sound like it has skipped a tooth?

pull all your plugs,(just makes it easier) and rotate engine over to tdc by hand. reverse rotation and watch how much degrees of crank moment you get before rotor moves. you can do this a couple of times and check movement and timing mark at tdc. sounds like your timing chain needs to be replaced..

 

good luck

[Cmal7]

Thanks for the reply.... I'm no expert on these motors but that is the only thing that make sense to me. If I can time it by ear and have it run well. Is it a big deal to leave it that way for a bit?

[diyer2]

Timing chain may have slipped or was replaced and assembled wrong, out of time?

Set it by ear.

[grampadirt]

Thanks for the reply.... I'm no expert on these motors but that is the only thing that make sense to me. If I can time it by ear and have it run well. Is it a big deal to leave it that way for a bit?

Probably be fine as long as there's no pinging.

[Cmal7]

Won't the cam, lifters, valves all be out of time? So when I replace the timing chain and reset timing should I expect the engine to perform quite a bit better?