Setting timing on 95 454

[Arcticsierra95]

Hey everyone have a couple of quick questions. First off, I've forgotten how to do timing on dizzy engines. Been in modern engines for over a decade now lol. I just finished assembling and got running my 95 454 gmc k2500, and need to know what to set the timing to, and if having a mild cam, ported heads, and 10.5cc dome pistons will require less base timing or just leave it to what stock is and have a chip burned

 

[GoToGuy]

What reference did you use for assembly? Doesn't it have timing and ignition? The factory service and repair, all the info you need are here, this forum free to download.

 

[Erik the Awful]

Mark your distributor housing with where the rotor needs to be to be spot on for #1.

Turn the balancer to 0°.

Check to see if the #1 valves are closed. If not, rotate the crank once and line the balancer up to 0° again. You're at TDC #1.

Check your oil pump driveshaft and make sure it's close to where it needs to be when you stab the distributor.

Stab the distributor so the rotor settles right onto your mark on the housing. You're at 0° on #1.

If the distributor doesn't sit all the way down, you've likely missed the slot in the oil pump driveshaft. Pull the distributor out, check the shaft, and re-stab.

The engine should start up just fine with 0° timing, and it's a quick and easy way to get it running. Do your initial break-in, check for leaks, etc.

Once you have it running solid, set the timing where you want it. Put a vacuum gauge on it and adjust the timing for the highest vacuum.

From there you'd likely need a dyno to realize more gains, but somebody else probably has more insight.

 

[Schurkey]

Adjusting timing for highest (idle) vacuum is almost guaranteed to get you overly-advanced timing.

Start with the factory-specified timing, experiment if desired from there.

 

[PlayingWithTBI]

Original timing was +4* with the EST wire disconnected. Then get your chip tuned from there.

 

[Arcticsierra95]

Original timing was +4* with the EST wire disconnected. Then get your chip tuned from there.

This is what I wag looking for. Thank you!

 

[Arcticsierra95]

Ok. So I "set the timing" to +4*, however I don't know what the connector is I have to disconnect? (sorry I haven't had a tbi engine since my 89 s10 when I was 14 lol)

 

[eran tomer]

if it's not stock engine you have to set it for the highest vacuum and then back it off until it doesn't detonate.

 

[grampadirt]

Ok. So I "set the timing" to +4*, however I don't know what the connector is I have to disconnect? (sorry I haven't had a tbi engine since my 89 s10 when I was 14 lol)

You'll find that connector inside the cab protruding from a bundle of wires hanging down below the glovebox,disconnect it before starting the engine(you'll notice it idling lower),set the timing @ 4° BTDC,shut the engine off,re-connect the connector.The idle should be higher.BTW,the wire is tan in color.Hope this helps

 

[Arcticsierra95]

Will try this tomorrow! Thank you.