johnt365

Hi all,

I'm a long time Chevy fan and recently bought a 95 GMC g2500 with a 350 to take some road trips with the family. My other Chevy is a 74 Corvette that I have restored and rebuilt. I mention this because even though I am comfortable around an engine, this van is a different animal.

I know the procedure for checking and adjusting ignition timing. I am hoping for some guidance from the van community on how to point the light at the tab!

I am hoping there is a trick to it or a magical tool that will let you check it without having to pull the shroud off etc. Everything is just a little bit tricky on a van it seems.

Thank you for any help
.

Best regards,
John

tech2

distributor are b4 my time but I remember my instructor setting his using a vacuum gauge; he could not see the timing marks.

turn the distributor until you achieve max vac...back it off 2" of vac and he was done.

mountainmanjoe

You can also hook up a scan tool and read the Cam Retard Offset.

johnt365

Thanks for the suggestions.

I think this 95 is going to be a challenge. The sticker says to set the timing to 0* which makes me think the computer is controlling the advance. And, this thing is OBD1 so it wont let me hook up my scan tool.

I gotta think about this one.

Thanks again

kevinkpk

You can set the advance with a vacuum gauge. I prefer a timing light. Piece of chalk on the balancer, mark the line, and set it with the light, and timing tab.

johnt365

How are you guys using a light? The tab is completely hidden and under the power steering.

Are you removing the shroud and fan? Even then looks like you’d need a mirror.

kevinkpk

Use a vacuum gauge.

oilcanhenry

Yeah, that's how I always did it too. Man, I am no fan of vans. Everything is a pain in the *** to do with those vehicles. Never owned one in my life, but I've worked on them.

oilcanhenry

Back in the day I saw guys time the engine by keeping the distributor hold down bolt loose enough to turn by hand hard. Then they would hit the road with it until the motor knocked. Then they would back it off until no knocking was heard, then tighten the dist. bolt down to spec. Those were the days!

johnt365

Finally got a chance to set the timing and wanted to report back.

So a 95 wants to be set at zero. To do that:

1. I recommend getting some white paint on a toothpick or something and get under the van and mark your timing line on the balancer.
Just makes it easier to see.
2. remove dog house and disconnect the advance connector. Its a brown wire with black stripe found in the wiring harness by the distributor.
3. remove the washer fluid reservoir. Key step.

Now when you shoot your light down you can juuuust barely position your head and the light so you can make out the tab. The make your adjustment to get to 0.

Hope this helps someone someday.

John