There is no mechanical advance in these distributors. Everything is electronically controlled.

Are you sure you got the proper gaskets for your truck? Felpro has a metal framed gasket set which will solve the problem of torque and material issues that the plastic framed gaskets have (FelPro MS98002T). The ports on that set are open on both ends.

About the bolt hole in the LIM, can you take a picture and post it?

 

I have not bought a gasket yet. So you are saying that I should try to attempt to open up those ports on the actual manifold Swartlkk? As to the distributor, so that rotational play is not normal? Do you think my distributor is bad? I was looking at it again this morning and I saw that it has stops near the gear that allow it to rotate that little bit. I do not know much about distributors, so that's why I am asking about it. I will take a picture of the L.I.M. as soon as I find my camera, which will hopefully be soon. Thanks.

 

Here is the picture you asked for Swartlkk. It's the third hole up. To me it looks like that is how it is supposed to be. I have tried looking up picture on the internet for reference but I always come up short. I can only find pictures of the upper plenum. i have also included a photo of the water jacket port in the back so you can see what I am talking about. It is like this for the other back water jacket port as well. The front ones are unrestricted and show no signs of this build up either.

 

That port does not go anywhere in the LIM I wanted to add a bleeder to each side to let air out of the system at these spots, but never got the chance to take things apart on my old Bravada again before I traded it in.

As far as that bolt hole goes, just make sure you have a good washer under the bolt and you shouldn't have to worry about it. I do not specifically remember that slot being there when I did the LIM gaskets on my Bravada, but it could have been.

 

UPDATE:

Ok guys, so I got my lower intake manifold gaskets put back in and torqued it down to the right specs and installed my distributor how it was supposed to be. Here is where my Blazer is at now.

I take it on the freeway and hit 70mph, and the check engine light starts flashing like it always has, I go back down under 70 and the check engine light goes away. If I get on it and go all the way to about 90mph, the check engine light still flashes, but it does not stay lit like it once used to do before. I can also get the check engine light to flash in park by just revving the engine up past 2500 rpm. I will not be able to access my scanner until Monday rolls around to see how the misfire is doing. Obviously it still is misfiring since the catalyst damaging event going on that is causing the check engine light to flash.

What options are left for me? I have changed the lower and upper intake manifold gaskets, I have upgraded the injectors from the poppet nozzles to the MFI injectors. I have changed my cap and rotor, new spark plugs, and new spark plug wires. My compression was consistent all around at about 155 psi each. I have run out of ideas and I am low on cash now from all these replacement parts. Once again, thanks for all your input guys. I appreciate it.

 

I also forgot to mention that once I hit 70mph, things begin to get shaky while I'm driving, but it goes away if I speed up or slow down to about 65 or up to 75. Don't know if that makes any difference. Thanks guys.

 

I once had a 95 Blazer and had a similiar problem several years ago. At turnpike speeds the SES light would come on and stay lit for several days and would finally go out on it's own after a couple of days of around town driving. When I took it to the dealer to get it serviced, I mentioned the problem with the SES light. They replaced the EGR valve under warranty (I bought the Blazer new) The old EGR valve was severely coated with carbon and they replaced it with a better designed EGR valve and haven't had a problem up until I traded it in. Maybe a bad EGR valve is your problem.

 

In the Haynes Book that I have, it says that my year, the EGR is electronically controlled, so wouldn't it throw a code if the PCM sensed that it were bad? Also, wouldn't my misfire be random instead of it always being cylinders 3 and 6?

 

I was also wondering if anyone knows how to check if the distributor is bad. How much play would I have. Gear wear pattern. The bushing inside of it. Cap condition. Things like that.

 

i had a similar problem on my jimmy,replaced just about everything it could possibly be (drove me crazy for 2 years) I pulled my distibutor and the gear looked fine,but the top bearing was dragging.I replaced it and it runs like a new truck. All that time and money .i would have never even guessed what it turned out to be.mine was throwing that p0300 and once in awhile p0301. I even bought a scanner with live data.i even thought it was the trans for awhile.I would recheck the distibutor. sorry for he long reply but i know what your going threw.