Hi guys. I replaced my loer intake gaskets. 2001 blazer. all went pretty well.
Got it all back together now it runs rough like a miss. Now the only reall trouble I had was getting the upper plenum back on where the connection for the spider goes. If it doesnt seal would that be a source for a possible vacuum leak?

 

The Manifold has gaskets on it for that very reason.
It has to be air tight. You have a Manifold Air Pressure(MAP Sensor)
that is taking constant readings that is attached to your Upper Manifold.

The Gaskets all have to seal properly.

An air leak will cause you nothing but grief.

Mark K

 

If you coat the oval shaped O ring with clean motor oil before you install the plenum, it makes it much easier to pull the fuel metering block up into the plenum. If it does not fully seat, (upward) it will leak vacuum, and the engine will run poorly.

Are you sure the nylon fuel lines are routed correctly? The cylinders are numbered on the side of the metering block. The lines on the right side are installed in order. Two of them cross over each other on the left side.

 

Thanks for the replies. I'm going to pull the plenum off again and see if i can get the spider assy to seat better. I'll definately try the oil trick on the seal. I did spray carb clean around the plenum and spider no change in the way it ran.

 

Not sure if it will help but I had a similar issue when I did mine. The cap and rotor has to be turned about 2 clicks before reinstalling it or else the gears wont line up and cause the ignition timing to be off

 

better check with Captain Hook to learn the proper procedures for this. Needs to have the correct type of scanner to read for correct advance settings. There is very little room for error here and it is very important to have it set correctly.

 

As for installing the distributor.... if the distributor gear is not correctly timed with the camshaft gear, P1345 will set in memory, and the check engine light will come on. No code, no light, you got it right! Checking & adjusting camshaft retard is a required part of the job when installing the distributor on this engine. It is adjusted, (using a scan tool) by slightly rotating the distributor, (ignition timing is not affected). MAP = Manifold Absolute Pressure.

 

The right side or the motor or the right side of the mechanic? Doesn't 3 go over 1 than back to 3, or something like that?

 

"Right side" always refers to the right side of the vehicle. On a LHD vehicle, (left hand drive) the right side is the passenger side. It is referenced this way, rather than driver/passenger side, to eliminate confusion for RHD vehicles. Right side cylinders are numbered front to rear, 2, 4, 6, and the left side is 1, 3, 5. And yes, #3 injector line crosses behind #1 to eliminate a clearance problem with the plenum during installation.

 

update looks like injector #5 is dead. got p0305 pulled spark plug wire and no change in idle or rpm, waiting on new spider to come in will update again whe i put it back ogether