Meet Tatanka, my 99 Suburban K1500

[tedly]

Now we get to the part that drives people nuts when they work on cars with me. See that glob of dried gasket goop on the end of the bolt? Buildup of that can cause a bolt to bottom out before it is actually tightened down. All that crud on the threads? Makes it more difficult to get in and out.The rust build up on the head? Makes it a pain in the ass to get a socket on there solidly and can lead to rounding off. Normally I like to clean hardware thoroughly with a wire wheel, then run a tap and die through everything to clean the threads. On top of making reassembly easier and more accurate, the next person to work on my cars is probably going to be me, so might as well make things easier on myself then. I wasn't at home, so I didn't have a wire wheel to chuck in a drill, or my tap and die sets. What I did have was a wire brush, a green scrubby pad, and some picks. I got everything cleaned as best as I could, including the mating surfaces, ran a bead of grey RTV around the cover, making sure to get all the way around the bolt holes, and stuck it back on.

I had looked at the cover before, checking the mating surface for flatness and seeing if the bolt holes had been deformed. It wasn't perfect, but the imperfections were small enough that RTV could handle it no problem. I found no leaks after filling the dif back up, so all appears well there.

Popping the dif cover and inspection took me way less than 30 minutes. Cleaning everything up took me over 2 hours. That's what drives people nuts. Maybe it's anal retentive. Maybe it's not necessary. I'm still going to do it though.

3 quarts of 80w90 ran me roughly $30, so total is now up to $2036.

[tedly]

That dizzy gear got me thinking, I need to get a better idea of what's going on internally. 220,000 miles is a lot, and there's a lot of preventative maintenance that gets skipped. Popped open the rear dif last night to look around and do a fluid change. I was expecting to find the spider gears or the ring and pinion chewed up but was pleasantly surprised. They are worn but not excessively. The fluid was sparkly and glittery, but no big chunks. There's a lot of metal on the magnet, but again, all very fine, small pieces. Wear and tear for 200,000 miles, but no damage. Cool.

[tedly]

While putting everything back together and buttoning it back up, I did find this:



This is the plug for the switch that was fubar-ed. Think it got a little hot?

I'm going to snag a pigtail from a scrapyard soon and swap them out. Meantime I made sure all the pins were secure with contacts bent down far enough to get good solid contact with the prongs on the switch. The wiring on the back was solid as well. I really don't like having that plug in use, but I got no choice right now. Just gotta keep an eye on things until I can get a new one.

[tedly]

Looks like there's barely enough room for a 1/4 drive ratchet and a shallow socket in there. Well, doesn't really matter because that's a 7mm bolt and I can't find my shallow 7 mil socket anyway. Got a wrench though. It was a pain in the ass, only turning it a little bit at a time. After getting one bolt halfway out I had the bright idea that maybe I should plug everything up and see if changing the switch solved all the problems or not.

It did.

I proceeded to do a happy dance.

And I could return the resistor.

I haven't been able to wipe the grin off my face for the last 2 days. There is something deeply satisfying about having things work the way they are supposed to instead of working just enough to get by. Plus it's saving my hearing, I don't have to have the fan on full blast every time I have the truck started. Plus I can hear the radio better now as well!

Up to $2006 now.

[tedly]

Done with that, now lets look at the blower motor resistor. Pop out the glove box and...

Holy s#*t there's not a lot of room in there. This is going to be fun.

[tedly]

After a lot of digging, I was finally able to find just the fan selector switch. I do mean a LOT of digging. You have to know the right question to ask the inventory computers to get the answer you are looking for, and the way everyone has this piece worded is very odd. Most parts guys don't even know it exists, but it's on the shelf of most stores. I wish I could give a part number or what I specifically searched for to find it, but I don't remember. If I find the box or receipt I'll update this.

The good news? Less than 25 bucks for it, and the blower motor resistor was $20ish.

Here's the back side of the unit with the offending switch circled and the replacement below it. I've gotten pretty good at taking that unit out and can have it out of the dash in about 5 minutes. Drop the steering wheel to the lowest it will go. Key on engine off, pull the gear shift all the way down into 1. Pop instrument panel bezel loose, you should be able to do it with your fingers. Maneuver the top out and clear of the dash. Pull out unit. Disconnect the 3 electrical plugs. Done. The retainer for the switch is held in place by one 5.5mm bolt and 4(?) latches, I can wiggle it out fairly easily once the retainer is removed.

[tedly]

By the way, here's Werner's solution for this when he had it: "I just punched the stupid thing until it worked again".

[tedly]

Since we've made it a week or two without any major car related emergencies, I thought I'd address some of the comfort and aesthetic issues on Tatanka. One of the things that has been driving me nuts but is not necessary for the truck to function was the ac/heater fan switch and blower motor resistor. The fan switch was just worn out and only worked on high. If I hit a bump, there was a 50/50 shot the fan would cut out. Hell, touching the selector knob would often be enough to cause it to go out. Putting sideways torque or pressure on the switch would normally (not always) get it to work again, but I just left the damn fan on high and would usually crack the window to regulate the temperature rather than risk pissing off the fan when adjusting the temp knob. It was serviceable, and I developed a light enough touch to adjust the temp without tripping the fan, but fiddling with that stupid switch while in rush hour traffic is not fun.

Initial searching around yielded only the whole control unit at $185 new and $80ish used from a scrapyard. No way I can justify $185 right now since it does still function, and getting a used one might mean I get the same problems.

[tedly]

Where are you tapping in to check fuel pressure? Our ‘90 doesn’t seem to have a schrader valve anywhere. Fuel filter looks identical to your setup, and it actually came apart and went back together without leaking or breaking.

Schrader valve is at the back of the intake on the driver's side on mine. The Vortec motors have a lot of differences from the small block before it. Heads, intake, injection system, and a lot more.

I tried getting the lines out the easy way first. The connector just disintegrated with any kind of torque. It wasn't coming off without a fight.

[SuperBuickGuy]

Where are you tapping in to check fuel pressure? Our ‘90 doesn’t seem to have a schrader valve anywhere. Fuel filter looks identical to your setup, and it actually came apart and went back together without leaking or breaking.

his is a 99, totally different fuel system. Your 90 has 11 psi, the 99 has 45-60..... vortec baby.

[STINEY]

Where are you tapping in to check fuel pressure? Our ‘90 doesn’t seem to have a schrader valve anywhere. Fuel filter looks identical to your setup, and it actually came apart and went back together without leaking or breaking.

[tedly]

Spend some time looking into the fuel system specs. Key on engine off prime should be 60psi minimum, idle should be 50-55psi. I get hold of a fuel pressure gauge a day or two later. Prime is difficult to get accurate because I can't see the gauge from inside the truck and it's falling by the time I get over to it. No way it can be higher than 58 though. Start it up, 48psi at idle. The computer can shut things off if pressure is below 50 from what I've read.

Wonderful.

OK, lets look around, see it there's any pinched lines or anything. Get to the fuel filter and the connections are rusted all to hell.



I guess it's been awhile since it's been changed. Probably clogged up. I wonder if it's 2psi worth of clogged?

Go out, grab a new filter, $14. Those lines are not going to come off there, so I might as well get the fuel line repair kits for them, $16 each. I'm probably going to lose one of the ferrules from the splice, so better pick one up as well, $4. Get the relay as well, $25. $75 total, so I'm into it for $1981 at this point. Picked up a mini tubing cutter for $11 as well, but that's a tool and doesn't count toward total for the car.



The filter is in an awkward location, and it took about 2 hours for me to cut through the old lines, splice in the new ones, and install the filter. It wasn't that terribly difficult, just took a lot of patience. It took a couple times of starting the truck, checking the connections, turning it off, then tightening the splices to get all them leak free, but it got done.

Put the gauge back on, primed it, 60psi. Cranked it up and got just under 50psi at idle. Like not even halfway to 49, but just a hair shy of 50. Close enough for me. Swapped the relays for added insurance and called it a day.

Runs beautifully and no more issues starting. I know I'm going to have to change the pump out soon because it is getting week, but this bought me some time and needed to be done anyway.

[tedly]

On my way to work a few weeks ago, I stopped at the local gas station to get some caffeine. Jumped back in the truck, cranked it and nothing. It turned over but not even close to catching.

Dammit.

Tried it again. Tatanka has always fired off right away, no hesitation. Same thing. OK... Is the pump working? Turn key on engine off, and nothing.



Son of a...

OK, lets look under the hood. Coil wire is still attached solid. Nothing has worked itself loose. Nothing unplugged. Fuel pump relay is not the same as any other relay in the fuse box, so no swapping it out to check that. Oh this is going to be fun. After about 15 minutes it just randomly starts on the first crank, like nothing ever happened.

Great. Fuel pump or the relay is going.

[tedly]

I live on the end of a 1/8th mile private road. There are 8 houses on our road and my house has 100% of the 4x4s. I also have a tractor - I like most of my neighbors (and I like getting the mail when it snows) so I plow our road.... that said, it would need to be a pretty rough situation if I couldn't get out.

I'm at the point in my existence where, if the plugs are missing, I won't buy the motor. A bit of coolant isn't really a big deal but flushing the rearmost cylinders could really keep it going for a lot longer. Really that motor isn't in terrible shape, but the days of garden-variety gas in it is over. I also would consider running several injector cleaner bottles through it. Around here, a 6 pack of Chevron injector cleaner is 12 bux at Costco - I'd run them all through, maybe even doubling up after the first bottle/tank. Don't double the first one, if there's big stuff in the system, it will mess things up.... by the second tank, the big stuff is gone and what's left needs soaking to get loose.

Perfect plugs - should be a light tan color.

And to help you read what you have, consider:

Tan is perfect
Grey means light oil getting into the motor (including from a bad PCV)
Grey speckled means knocking (all of this is on the white part) - and this is, literally, aluminum being blown off the piston...
black means soot - running rich
shiney black means you're laying down a smoke screen
Red/Rust means water is getting into the cylinder
missing tip means lean
white means excess antifreeze/water (also white built up like a calcium deposit)

there's a lot more but those are the majors - you can tell how a motor is running by how the color changes from the tip to the base of the insulator. A proper running Vortec will have tan on one side and white on the other.... because it burns the mixture so well that the flame path doesn't make it all the back around the cylinder... pretty cool, huh?

Thank you for the info on plug reading! That is massively helpful!

As for the fuel system, funny you should mention that... It's had a couple cleaners run through it in the last year, and the next installment involves the fuel system.

[tedly]

Thanks for documenting this adventure Tedly. Our '90 4.3 manual shift 1/2 ton 2wd has taken to hiccups (or lean mis-fires?) on occasion with no apparent pattern. Although lugging the engine by an early shift you can get it going almost every time, and if it does it once it will do it worse and worse once it starts.

And other times it never does it at all, on the same drive to work.

You have given me a place to start. Have already done the fuel inj cleaner and new filter, no permanent change although I did think there was a brief improvement after the filter. Might have been my imagination.



Your property is really cool....though I sympathize with your driveway. I grew up back a 1/4 mile drive - they definitely have their good and bad points.

That sounds real familiar. Pop the cap and wires off and turn the crank at the pulley. Go back and forth. If there's a dead spot, you know what to do. For a long time the misfire was intermittent and showed no real pattern other than flooring it for a few seconds would often clear it up. The closest thing to a pattern was it got steadily worse until it was constant. It was infuriating.