This A-1 guy nails the top 5, heater core, LIM, etc, maybe nothing new if you've passed 100,000 miles. then at 7:15 he explains how a bad switch in the transaxle can push fluid up the vacuum hose into the actuators in the HVAC so doors wont open.

 

I'm kinda surprized he didn't mention the stupidity of putting that large actuating vacuum servo UNDER THE FRIGGIN' BATTERY! It gets battery gunky-stuff dripped on it, and that corrodes and causes a lot of troubles to the front axle actuator.

Also -- the 4.3 has a plastic distributor --- it's "good" GM plastic and therein lies the oxymoron; "good" plastic is still plastic and is generally OK but not as a distributor housing!

Many people find the 4.3 drinks gas too fast to be considered an economy engine --- and it's basically in the locked-down distributor where the economy fails.

You might notice the distributor cannot be turned to set the timing --- and YES -- there is a scanner-viewable timing value, but you cannot get it to be set where a normal intelligent person would like to set the distributor. As it comes from the factory, it cannot be moved and maybe some people think 23° RETARDED isn't - er, retarded --- well I dunnow!

When you run the basic crankshaft timing test, you'll find it's strange --- like 23° ATDC (retarded) - and you think: "hopefully the computer" can assist to get it to a better location once it's running (it does, just a little, but not much) and the computer sets the timing itself - electronically. However - here's the big fly in the pudding problem --- the Cal/EPA settings are at a retarded 23° ATDC, and they don't get much advance at all -- well, unless the engine gets overheated and then it will throw some advance into it like a life preserver to a drowning man.

If you remove the distributor hold-down foot or clamp or whatever you want to call it, leaving the distributor where it is for this modification - and carefully grind the flat spots on it --- (you'll know what I mean when you see it) --- and make it so you can rotate the distributor inside that hold-down - you can actually get the basic crankshaft timing to +7° BTDC to +10° BTDC --- that's ADVANCED before TDC!

You'll find your gas mileage might come up (as it did for me) a solid 7-10 MPG!

FTR - in a 2000 Astro Van 4.3, I went from 12.5 MPG to 22.6 MPG with that change alone! This was a fairly slinky - airflow version van body but it was still a huge loaf of bread pushing a lot of air outta the way on the road at 60 MPH. Aerodynamic, it was not --- and I suspect a smaller S-10 should be cleaner going through the air.

......... just sayin' .............

 

Bass Surfer, timing cannot be set by turning the distributor. That is determined by the crank sensor and the PCM. Distributor only distributes the spark from the coil to the correct cylinder. Sounds like you are setting cam sensor retard, which is accomplished by turning the distributor. However it should be set to zero +/- 2 degrees.

 

The problem - as you don't see it - is that the distributor is locked into 22.5° retarded - and then the computer is supposed to take over once the key goes into crank mode.

From there - if the engine starts, the timing is always carried by the computer - but it works off the base-timing value and afterwards can advance into zones where it is never gonna go if you don't advance the whole distributor.

It works --- it bumped the power and fuel mileage 'way up and for years I was dumb and stuck with that lousy performance before I noticed this changed it.

It boils down to setting the timing in the "usual" way by revving the engine in neutral up to just before the Fuel Cutoff and then the timing is "learned" - but this time in a whole different ballfield.

Base-timing is what it's all about --- as I fouhd when I had to certify cars coming into California for emissions - and even California cars that had lapsed their registration date. The whole vehicle then had to be inspected and brought to CalEPA / CARB standards - and with the clamped/locked distributors, it was not easy.

That's when I figgered that by rounding-out the hold-down bracket, I could set the base timing where I wanted and the computer would hold it retarded as coded-in while the engine was 1. running 2. below overheat 3. under 35 1/2 MPH (this is where the VW got themselves jammed up 'cause they let the engine get decent performance and timing after the road speed indicated over the upper-limit threshold set by the EPA --- but VW must've missed delivering some plain brown envelopes because every manufacturer did that --- after 35 1/2 MPH --- emissions be damned!)

I know you don't "get it" but that's how it worked.

 

You can't set base timing by turning a distributor that has no pick up coil. Think about it.