Ok, so I have a mechanic buddy that ran some tests & said my fuel pressure regulator is leaking causing the miss, erratic rpms & exhaust fumes. He said it could also be the spider assembly, but he's done a lot of them & it's usually the FPR leaking. Said it dumps fuel & will wash down one or more cylinders.
He told me I might as well replace the spider assembly while I'm at it & upgrade to the MPI to get away from the poppets. Does anyone have a part number/brand recommendation for this or does it matter? Prices seem like they are all over the place on this from $200-$400+.

I had a code come up as a bad lower intake gasket. before it started running like crap, so I plan on doing that job while I'm in here too. Do I need to replace the intake manifold bolts as well?

Is there anything else I should go ahead & replace while I have it apart? I would rather not have to get into it again to fix stuff since I plan on keeping it for a while.
We were going to trade it in, but I have my wife convinced on trading in the '09 Yukon when we get her a new car to avoid having 2 car notes.

Vehicle is a 2001 Blazer LT 2wd with 149,000 miles.

 

A.C. Delco or Delphi only!!!! Yes replace and upgrade since the regulator is in the spider anyway. I've never read anything that says replacing the bolts is necessary so I wouldn't worry about those. I believe Felpro makes a gasket kit for this so just take the time to make sure everything is clean and replace all the o rings and things as you go and you should be good. Also don't forget to mark your distributor and pay close attention to which way it turns when it comes out to save yourself headache later!

Oh and there are a couple o rings and a spacer on each fuel line going into the spider assy that Wi you will want to be aware of and pay attention to because they are different sizes and incorrect order of install will cause leaking. The spider will come with new parts but no instructions on which order they go.

 

I did see info on being careful to mark the distributor when pulling it. I am replacing that with an all-aluminum one since the screw hole tab broke off of the original one. It should be delivered tomorrow.

 

 

There are no codes that tell you that the intake gasket is bad, somebody is yanking your chain


Might want to go through this to thoroughly check the fuel delivery system. https://blazerforum.com/forum/2nd-ge...eakdown-88305/


The lower intake bolts do not need to be replaced, however: You need to chase the threads of the original bolts, AND the threads in the cylinder heads, (5/16" x 18). Then apply thread sealer to the bolts just prior to installation.


Felpro gasket set MS98002T will not leak if prep, cleanup, and assembly is done properly. Follow these instructions for tightening sequence and torque values:







This image, (original CSFI injector assy) shows how the O rings, washers, & retainers are installed in the fuel metering block:



Before removing the distributor, (no need to mark anything): Use a socket & ratchet to manually rotate the crankshaft clockwise until the index marks are aligned like this:





AND the distributor rotor is aligned like this:



When reinstalling the distributor, make sure the rotor is pointing at the "6" on the distributor housing when the distributor is fully seated against the intake manifold.
DO NOT operate the starter, or move the crankshaft, while the distributor is removed.


EDIT: Aluminum billet distributor is a great upgrade, but, toss the cap & rotor that come with it, and install AC Delco parts, (aftermarket caps & rotors don't make the grade on this engine ).

 

Dang you captain for making my response feel inadequate with all your complete and accurate information and fancy pictures lol! I wish I had that schematic for the o ring installation when I did mine and that's all I'm saying about that.

I will add that when I installed my aluminum distributor I had to open up the hold down bolt hole and make it slightly adjustable to allow proper setting of the cam retard and clear up the random misfires. Doesn't seem like my experience was unique either cause I found the solution in 2 seconds with a Google search so that's something you may want to keep in mind if your having misfires after getting everything back together even if you follow the install instructions perfectly.

 

Oh no, don't feel inadequate, I need to thank you for reminding me of all the stuff At my age I need all the help I can get so my CDO can kick in. CDO is like OCD, but all the letters are in alphabetical order, the way they should be


EDIT: I usually toss the hold down bracket and install a SBC hold down.

 

Yep, that's the one to get, and where I got mine. But Rock Auto is a whole bunch cheaper than Amazon for this item these days. Prices seem to vary widely. Shop around.

 

I totally forget about rockauto all the time. I'll check there to see if I can get it cheaper. I decided against doing the lower intake job at this point. Just going to do the spider & see how it goes. Wife wants me to get rid of it because she thinks it's falling apart & I want to keep it because I don't want to car notes. So I'm not going to go to that extent for now until the debate is settled. I just need it running right until the end of school. Once the kids are out for the summer, I can handle it being down for more than a day then.

I don't know how their computer determined it, but I personally read the readout on Autozone's computer screen & they gave me a printout of it. Came back as a "multiple misfire on #3, lower intake gasket failure". I may still have the printout they gave me. If I can find it, I'll scan it & post. I had them test it when it popped a code not long after I did the tune up. But I can believe that those fools at Autozone would makes something up to sell parts. I typically don't go there but the computers were down that day at O'Reillys & it was the next closest place.

The leak down test is how my friend helped me determine it was the FPR leaking. He works for a local shop & brought his gauge kit over to test it. Considering the pics I've seen of others with the washed down intake, it's likely that this was the the original misfire issue.

I got the dizzy in the mail today & had already planned to toss the cap and rotor that came with it in my carry all parts/tool box as an emergency backup. (A habit from driving old VW's. You never leave home in an old bug without a spare cap, rotor & set of points in the glove box)
I plan use the cap & rotor that is currently on it now since they are AC Delco brand & less than 2 months old.

 

Oh, thanks for this info especially. It takes all of the voodoo mumbo jumbo juju about marking where everything is at that I've found online out of it & it makes a lot more sense.