I'm about to replace my lower intake gaskets along with the CPI spider, nut kit and plenum gasket on my 1994 4.3 Vortec.

I can only find tutorials on other generations and they all say to move the A/C bracket/PS pump bracket to get at the bolt in the corner of the intake. My engine has the alternator here and A/C on the passenger side. Do I have to move the bracket to get the intake off in my Blazer? I really don't want to because from what I can remember from replacing the P/S pump, there is a bastard of a bolt behind the pump holding the bracket and I have to loosen the P/S pump to get to it which means removing the pulley which was a PITA. From what I can tell I don't but I haven't gotten into it. Also, does the distributor go through the intake on my. Do I have to remove it? Can anyone link me to a tutorial on replacing the lower intake gasket in a CPI 1994 and older S10 Blazer? I've searched and searched and had no luck.

Thanks

 

Isint the lower gasket considered the head gasket? Unless you are leaking oil out of the block I don't think you need to do anything with it. If your spider is bad there are bolts that hold the plenum on all the way around and once you get them all out you can lift the plenum off to get the the POS/worst design for a fuel injector ever otherwise know as a spider injector and then get a new plenum gasket and torque everything down, you need a torque wrench if you wan't to do it right. Search this forum for spider injector and something will come up, there are a million posts about it.

Here is a search https://blazerforum.com/forum/search...archid=1420674

Also replace the connector that clips onto the spider. If I were you I would just replace the fuel regulator for $50 and save your money since they are really what fails most often.

 

it might just be 95 and up. you can always leave that part for last. or just look to see if you can get that bolt out. that side bolt does suck to get out, ive done intakes where that bolt was missing cause someone didnt put it back lol.

 

Crows feet are a mechanic's best friend. Probably won't need to touch any of the belt driven accessories once that bolt is out. Might be a bit tight though trying to lift straight up.

 

Before you get ahead of yourself what is your problem? IS your spider leaking?

 

I have several problems that I'm trying to address. I'm losing coolant which I suspect is leaky lower intake gaskets. I have crappy gas mileage, running really rich, oil level is rising, etc, which is likely the spider/nut kit/fuel pressure regulator. When I rev it in park, the exhaust leaves an oily black streak on the pavement. I think it is a combination of vaporized coolant and unburned fuel/rich exhaust. I know exactly what to do when it comes to replacing the injector spider, etc. I have all of the parts already to tackle this project. All I needed to know was the details on the lower intake gasket.

 

Here's a pretty good tutorial on a 99 which may help.. of course a lot of accessory drive disconnects and moves are different.

How To Replace Intake Manifold Gaskets On A GMC Jimmy 4.3 Liter V6 To Fix A Coolant Leak - GM Truck Engine Repairs

I wouldnt recommend taking a dremel sand disk to all mating surfaces, though. I plan to clean them well and spread a THIN film of high temp {400F} silicon grease to the intake surface only

 

Just an update. The project is halfway done. I got the intake off. I replaced the nut kit and injector spider. The fuel pressure regulator was toast and there was a big puddle of gas on that side along with some washing of the plenum walls. After getting the lower intake off I made a decision to hunt down the halfassed moron who worked on this thing previously and revoke his tools. For starters, the screws on the distrubutor were mismatched as were the plug wires. No big deal, but then I discover that one of the injector poppets was glued in with the same gasket sealer that was used on the entire lower intake gasket surface which was ridiculous to clean off. Most of the rest of the poppets' tabs were busted off and one was broken at the plastic bits that surround the nozzle. So now all the gasket surfaces, upper and lower intake, are nice and shiny. I took a tap to all of the intake manifold bolt holes and cleaned up the bolts with a copper wire wheel. Tomorrow I will put it all back together but I have two problems:

1. I'm doing the t-stat but the the round gasket is not fitting. It is a larger diamenter than it should be. I figured it could be trimmed down and then put it around the t-stat and stick it in the recess. But the groove isn't deep enough in the gasket and it doesn't want to go into the recess. I think I have the wrong gasket but I got it at Advance Autoparts and the guy who sold it to me has had 4 of these model Blazers. If the t-stat is 44mm then this gasket is like 60mm. Anybody know what's up with this?

2. Can anyone tell me the tightening sequence for the intake bolts as well as the torque specs for each of the 3 tightening stages?

Thanks for the help. This is my first Blazer. I rescued it from going to the junkyard for the low low price of $450. I've dumped a ton more into it but I think this is about it for now. So far I've given it new tires, battery, muffler, EGR valve, plugs, coil, trans mount, fuel filter, 2 oil changes in 1000 miles because it was low and blaaaaack when I got it, serp belt, PS pump, belt tensioner, both knock sensors, rear hatch handle/lock and window struts. Add in the injector spider, nut kit, plenumgasket, lower intake gasket, plug wires, dist. cap, and t-stat. The rear driver's side lug nuts were pretty much frozen on and had to be torched and I gave it a cooling system treatment and flush, but the coolant is still rusty looking. Can't really treat it again unless I find a product that works in freezing temps. I'm giving it one more oil change tomorrow after running it for a few miles to get any crap from this project out, and new anti-freeze. I think I'm done though. This latest fix should be it for the immediate problems. I've only owed it for 2 months, I hope it lasts me for a little while. I need it to pull a food cart till I can afford something nicer and newer.

 

Well, got it all back together but now it is beyond sluggish. I'm having trouble reaching 30mph. I'm not 100% sure I got the distributor perfectly back into the right spot, I pretty much washed off the mark I put on the intake manifod after I removed it and cleaned it up a little. It starts fine and idles but is a total dog. I know I got the distributor shaft in the right gear tooth, I etched the firewall where it pointed. I don't think I got the body of the distributor in the right spot. It won't go anymore clockwise, it's about 1mm from the touching the intake. Is my timing probably off? How do I set the timing on a 1994 S10 Blazer vin W with the 4.3 CPI V6?

 

Just give the distributor a twist & take it for a drive. I think there's a connector somewhere on the firewall, passenger side, that should be removed before adjusting the timing. I never did that so I couldn't tell you exactly.

I'd give her a slight twist one way or the other, then go for a drive & note the performance. If it gets better, then keep going that direction until it runs normally. If you twist so far that it stops (from dist. connectors hitting something) and it doesn't get any better, then you might be a tooth off.

Also make 100% sure you got every single vacuum line back where it's supposed to go. A big vacuum leak will do the same thing, but will usually idle like crap too.