When you get ready to do it, there are several do's, don'ts and tips that we can help you with. Starting with the gasket set: Felpro MS98002T. Keep us posted.

Ok I did the lower intake gaskets no change in the way it's running but once it was back together I could hear a vacuum leak near the top of the plenum I sprayed quick start around where the spider injector sticks out of the plenum and it changed the revs so the gasket on the spider injector is obviously not set in place so I will have to take off the plenum again and try and get it on where it should be. I wish I saw your last post before I did the intake gasket hook what are the do's and dont's incase i didn't use enough gasket maker and have to do it again

#1. DO NOT use starting fluid, (ether) on an internal combustion engine! One stray spark, or a backfire, and you have an instant flash fire in your face. Use carb cleaner spray.


Did you use the Felpro MS98002T gasket set?


Clean all gasket sealing surfaces. Clean 'em again.


These next steps are VERY important: Clean and chase the threads on the intake bolts, and in the cylinder heads, with a tap & die. Then apply thread sealer to the bolts. Follow the tightening sequence and torque specs listed here:
Attachment 30934
Notice that the bolts are torqued in INCH pounds, NOT foot pounds. Due to the low torque, thread sealer must be used to keep the bolts from loosening up and "walking out".


Apply clean motor oil to the oval shaped O ring on the fuel metering block to help it slide up into the plenum, and fully seal, so you don't end up with a vacuum leak ;)

I think you need to be more specific Captain so you said there is do's and don'ts but I must have thought you said do the don'ts lol cause that's what I did. I didn't use the Felpro Gasket but not because I didn't want to take your advice. Only because when I ordered the spider injector gasket when I first did the spider injector I could only order the whole intake gasket set so they came with it and I already had them and since I'm on a limited budget I just had to use what I already had. They were whatever NAPA gives you when you walk up to the counter and ask for the intake gasket set for a 99 Blazer 4.3

What did it look like?


This is the MS98002T. It has a metal frame sandwiched in rubber: http://www.carid.com/images/fel-pro/...s/ms98002t.jpg




This is the MS95817. It has a plastic frame and silicone seals: http://ecx.images-amazon.com/images/...eL._SX425_.jpg

it looked like MS95817 BUT BLACK PLASTIC WITH BLUE SILICONE OR RUBBER

That's the OEM style:( Prone to leaks.

Here is a link with detailed instructions on how this guy cleaned his own poppets.


Poor Mans Repair Guide For Chevy,GMC Vortec Fuel Injector spider or CSFI System

Alright Captain so I think I might have to re do my intake gaskets I took off the Plenum today to try to re seed that spider injector gasket when I took it off I noticed creamy sludge inside if the intake gasket was not done right could it spray coolant up in the plenum from the lower gasket? I'm not sure because at the same time I blew a coolant hose and had sprayed coolant all over my engine and because there was that vacuum leak it's possible that it sucked in in through wherever the vacuum leak was.

Never seen coolant inside the plenum before, not on a 4.3L anyway. If the plenum gasket, throttle body gasket, or the oval shape O ring was leaking vacuum, and coolant got sucked in, that would be about the only way possible. If the creamy sludge is under the lower intake manifold, yes, a leaky intake gasket would definitely cause it.