Hello All

I just bought a 1986 G20 carbureted 5.7L Van. My first Chevy. I know shes old but its in great shape and 147,000 KM's !! Its got a heavy duty emission exhaust and i believe 3/4 ton chassis. I am looking for any shop manuals or service manuals for this van. It needs engine work as it wont start. I believe the timing is out of whack and may have jumped a tooth. So i have a series of questions:
1) Any advice on replacing the timing gears and chain
2)I want this motor to run sweet so what else should i do to it to get the best running results. I am looking for a reliable somewhat fuel efficient engine. Any upgrades to consider?

thanks in advance for any advice

 

Start with a Haynes or Chiltons manual. As for fuel efficient, not gonna hapeen with a G20.

 

Hi bruisermac,

Welcome to the Chevy Forums.

It sounds like a cool truck. "G" denotes 2WD van, "20" denotes 3/4 ton suspension.

Metal double-roller timing chain and gears to replace those manky nylon gears and that stretched chain. The additional cost is negligible compared to the scope of the overall job.

While nauticastar is right about general fuel savings, that's no reason to give up the ghost on gas mileage. A whole range of small things effect drag on your vehicle and your overall fuel economy. With a cross-section in the wind as big as your van, believe it or not, a good wax job will save you some gas money, especially on long trips.

If your shocks are shot, get a good set of stiff gas shocks. Increase the inflation of your tires a couple pounds.(NOTE: ONLY two or three pounds!!) A good tune up will work wonders.

Have you changed the transmission filter yet? This gets ignored a lot, and could be holding you back from gas savings.

Visit Ecomodders.com for 100 fuel saving tips.

Record your MPG now, and start keeping track as you make improvements. You'd be surprised.

 

thanks for the advice wolf. i will definetly change the tranny filter when i do a complete fluid change on the machine. she needs a bit of loving thats for sure.

 

I'll be posting a similar reply in another thread. The older harmonic balancers can be a bit tricky. With this style engine be very careful to keep an eye on the rotor and distributor vacuum. Also, if the timing mark doesn't show up where it should under the timing light, there's a distinct possibility the harmonic balancer has slipped, and the original timing mark isn't accurate.

One low tech solution: Set the timing by ear. Tools include a heavy, clean, dry rag, your distributor wrench, and what God gave you:

1.Set the transmission in park,let the engine warm up to a low idle. Shove a plug or a pencil in the distributor vacuum advance hose.
2.Carefully loosen the distributor hold down clamp.(you may have to do this prior to starting the engine , if it's idling too rough.)
3. Grip the entire distributor body from the top with that heavy, dry,rag. Turn clockwise till you hear it start to misfire, then back it slowly in the opposite direction until it just starts to run smooth. After you've done this a few times you can sort of "feel" a sweet spot.
4. Tighten the distributor hold down clamp and reconnect the vacuum line. The timing may not be perfect, but it should be very close.

 

Factory service manuals are sold on Ebay and are normally priced the same as the off the shelf stuff with tons more info in them.

 

A couple of our pros here also swear by alldata.com...