Nuthin to do with bikes

[webbcraft2150]

Scored a 97 S10, 2wd, Tahoe edition Blazer the other day for $750. Perfect interior, body and paint. Runs like ca-ca. I suspect the typical spider injection problem. I found out what the f spider injection is. Interesting if not weird way to get fuel to an engine. PO had given up on it with rough idle and lack of power. His loss my gain. Parts on order to fix er up for the daughter who used her '90 Cavalier once to many to bump stop the car in front of her. Nice thing is it is OBD 1 so I can pull the codes with a paper clip. If yall have any advice on this rig, lemme know. Unknown territory for me but I ain't sceared.

[CRXSi90]

Yup, keep an eye on the oil and coolant. The intake manifold gasket isn't that robust on the 4.3. I'll write more about my 1998 s 10 in the morning.

[CRXSi90]

I have a 1998 S10 pickup extended cab, 2wd, 4.3L v6 engine. One thing to watch out for is the failure of the lower intake manifold gasket.

For some background...
The lower intake manifold is cast aluminum and has passages for air to go to the intake ports on the heads. Also, it routes coolant to (or from?) the heads. Due to the difference in thermal expansion between aluminum and cast iron, and the use of a plastic (nylon?) gasket, sometimes the gasket can leak.

What to look for...
When the gasket leaks, it can allow coolant to (1) leak externally to the engine (2) leak to the intake passage (3) leak into the valley and mix with the oil. For this reason, it's important to keep an eye on the coolant level and the condition of the oil. If coolant mixes with it, it will look milky. It's easier to see when the engine has been running and the oil has warmed and circulated, because the water/coolant tends to sink to the bottom, leaving you to think that you have no problems. Another strategy is to look inside the oil fill cap and see if the cap/neck look like a creamy latte.

My experience...
My truck had symptoms of rough running and coolant consumption. It turned out that I had a cracked head, which allowed coolant to drain into the combustion chambers. That's how I found it, anyway. My guess is that under the care of previous owners, it had a coolant leak (intake manifold or otherwise) which resulted in the engine overheating. They probably fed it cold coolant which put excessive thermal stresses on the head and caused it to crack. After replacing the head (and along the way, the lower intake manifold gasket, which appeared to be in need of replacement), it run much better.

As far as spider injection, yes, that's another problem area. I didn't dig into that when I had the intake manifold off. Two notes that I can think of on that:
(1) Look at the fuel pressure regulator while you have the upper intake manifold off. Those are known to leak, too. You can begin to determine what's leaking by looking to see where the carbon/whatever has been washed off the aluminum casting.
(2) The recommendation I always see is to buy a new, rather than rebuilt spider. Supposedly it has a different design. The original has one solenoid valve at the center of the spider, and nozzles at the end of each leg. This system has to balance the flow between cylinders, which is a bit of a circus act. The redesign just has a manifold at the center which sends ~45 PSI (?) to each injector, where there are individually controlled fuel injectors (wires controlling all six individually). They still all pulse at the same time, like with the original system.

Best of luck with your spider replacement. I'd like to hear how it goes.

[webbcraft2150]

Thanks for the info. I looked into the injector upgrade but its a no go on a "94. I got a Delco reman spider with new pressure regulator and injector. Also got the "fuel line repair kit" to replace the the plastic pressure and return line in the plenum. I hope the extra I paid for a Delco will pan out. Has in the past. Got a Delphi fuel pump also. I had read about the fragile intake gasket so I figured if I had the plenum off, I was already half way there so it gets replaced also. The rig has to go to Colorado, a long way from my toolbox so I am going thru it with a very critical eye. Parts should be here by the weekend. I will let you know how it goes, and acts when I get done.

[CRXSi90]

It's nice of you to set your daughter up with a reliable vehicle. So it's a '94 or '97?

One other thing I had to deal with was the drive shaft center support bearing and double cardan joint. I'm not sure if you have this on a blazer. The problem was that the drive shaft would flop around @ the center support bearing. Turns out that the double cardan joint was worn out. I had a shop make me a new shaft that just uses a standard u-joint in the center. I don't think this is a particularly common problem, but it might be worth pumping some grease in the joints if you can do that. I seem to remember that it didn't have a standard zerk, but rather just a hole that you shove a tapered needle into to grease.

[webbcraft2150]

Its a 94, 4door AT, 2wd. Fortunatly the drive shaft is a one piece and the PO just had u-joints replaced, one more thing I don't have to do. Saturday is wrench flying day. New fuel spider, fuel pump, belts, hoses, lower intake gasket, rear window struts, trans and motor mounts, trans fluid/filter change. Sounds like the cat converter is rattleing so that has to go to. Lucky for me its a bolt on and not a small fortune. Hafta have it road ready by thankgiving to go to Colorado. Optimistic I can get it all done this weekend.

Oh, and I ain't "giving" it to her. She gets a title and a payment book. Daddy bought the first car, she pays up for this one. Might have about $1500-1600 in it when I am done but I think it will be a study rig. If I added my labor, she would be into it for about 6K. Things you do for your kids

[CRXSi90]

Let me guess, it all took a little longer than you expected? That's the way it always goes for me.

[webbcraft2150]

Update. Pulling plenum and lower intake took a total of 4 hours which included heavy cleaning of all parts. With upper plenum off, there was about a pint of raw gas puddled in the intake, sure sign the system was leaking. Did the lower intake gasket cause I was already there and they have a bad rap of going out, worth the $13 in gaskets. Ran better, threw a bunch of codes, 5 of em. Chased em all down 'cept the EGR solenoid/valve. Cleaned it twice, still no luck, new one on the way. Runs good till the CEL light comes on showing EGR is hanging up. So the rundown so far, fuel injection system, fuel pump, change diff fluid, trans mount, trans fluid and filter, MAP sensor, TPS, knock sensors, coolant sensor, OP sensor, motor mounts, belts/hoses/thermostat, front brakes and seals. New cat converter coming and hafta chase down the ABS problem (or pull the bulb). Between Amazon, Advance, Rock Auto and the local Wrench-a-Part, I should squeak by just under a total investment of 2k. Had the body and interior not been in as good a shape as it is, plus new tires, I would have passed on the project. 2k and no payments, my kind of rig.