so if I was going to remove the plenum for inspection would I need to replace the gasket as well or will the current gasket still be functional.

 

you should really replace it. but if it doesnt split apart when you take it off, you might be able to recylce it. however id put a very light skim coat of RTV gasket sealer on it....

 

I apologize for the slight necro of this thread, but I have to say that the information here has been absolutely phenomenal. I was having problems with my 95 Blazer and stumbled my way here.

All the symptoms my truck was having matched what I found here so I pulled everything apart today and found exactly what I thought I would. Here are some pictures because I want other opinions before I start dishing out money for parts.








From what I've read in earlier posts I assume my regulator is the problem due to the staining directly underneath it. On the other side I know I need a new nut kit because as I was pulling the lines out I could see and hear two leaks in the line.

So my question now is am I right in assuming my regulator is the problem, and if so, would it be okay to just buy a new regulator and nut kit for about $130, or should I shell out the $400+ for an entire new assembly and nut kit?

Again, thank you for all the helpful info in this thread!!

 

You can pull those 6 spider ends out of the holes by pinching the 2 tangs together and pulling them straight out. Then they will be pointing down by the holes. Have someone else turn your key on and see what happens at the ends of those legs. If they dont spray anything, you could probably reuse them, if anything comes out of the tips at all then replace the spider too. That leaking you have there is bad. It looks much worse than mine was and mine wouldnt even startup. My leak was the tips of the legs though, nothing else. They just wouldnt hold pressure and would **** out fuel from each when the key was turned on. I took the whole unit from a wrecker astro van for about $30 and it worked just fine.

If you want peice of mind, then change the works.

You may also be interested in changing the harness on the top of the injector. It has a little rubber insert that keeps it steady and when you pull the harness off, its rubber, and rubber doesnt like gasoline so its probably all eroded away. Wiggle the harness and see if its tight. That harness is about $14 canadian but you have to ask for one for a 95 1/2ton truck, not a blazer... This is cause their computers just dont have the part listed under the blazers at NAPA. Just cut the wires off close to the injector and pull them through the gromet, then push your new ones it and do the trimming to legnth and soldering on the outside of the plenum. The new harness had a neoprene anti wiggle thing, not slimy black rubber like the factory one was.

 

you no longer have to spend $300 on a new spider if you need one. you can get a rebuilt GM spider from Rockauto.com for about $119 and looks great. just thought id let you know

by the way, you need to clean out the hole for your EGR valve because you can see its clogged in the picture you posted...

 

Thanks for the tips. I went ahead and just changed the regulator and nut kit, cleaned everything out the best I could, and buttoned everything back up. Sadly, now, for some reason my engine won't turn over. I hope it's nothing serious. Any ideas?

I absolutely did just that.

 

"Wont turn over" to me means that you turn the key and the engine does not rotate...

Or do you mean that it rotates and does not start up? If you were cleaning up all that mess thats inside those 6 intake runners, then you have cylinders full of the garbage that runs down the runners and its going to be hard as hell to start up the first time. I would have taken that intake off to clean it up. Can you start it up by squirting some gas into the throttlebody and turning it over?

Im assuming you bought yourself a fuel pressure guage so you can test the repair you just did, what kind of fuel pressure are you holding at now? How was the condition of the injector harness? What did you do for your repair? You would have done well to leave the upper plenum off and do your fuel pressure test so you can witness a leak if its happening. You will probably want to change your oil as well cause you had a BAD leak there and the oil probably reeks of gasoline and is overfull. If you dont change that thinned oil out you are looking for a spun berring or washed cylinders.

How did you get that nut kit out of there without pulling the intake??? Just curious cause I had to pull the intake to get mine from the donor truck. Maybe you forgot to plug the distributors wire plugs back in when you had it out to get that nut kit out.

Key on you should get 58-60psi, then turn the key off and it should hold at that level. If it drops off then you still have a leak. If its not up to at least 55 then the injector wont fire properly. Its possible you got a bad regulator, the only way to know that is to test the fuel pressure once its all done. You didnt turn that little torx screw in the end of the regulator at all did you because thats what sets the spring tension inside of it to regulate the pressure. If you turned it at all it could be out of spec now...

Just throwing some things out there.

 

And did you replace your spark plugs because they are more than likely seriously fouled?

 

New fuel pressure regulator
New nut kit
New spark plugs (yes, the plugs were burnt toast)
Oil change

"Won't turn over" in this case DID mean the engine wasn't rotating. I had a hydro lock. I was an idiot and forgot to put the retainer clip back on the fuel lines thus flooding the cylinders, mainly #3. Pulled the plenum again and cleaned up all the excess fuel, pulled the plugs (and boy don't we love working on plug #3), manually rotated the engine, and put the plugs back in.

As for the nut kit removal, I didn't have to pull the lower. I pulled the hard lines out and spun each line to where the slot for the retainer plate was face up. Simply pushed them out the back with a flat head screw driver.

Got everything buttoned up again and got her fired up and running. I'm kind of proud of myself for being able to make this repair. Thanks for all the helpful information.

Unfortunately, when I got her going I had white smoke coming out of the tail pipe. Checked the oil and it looked like a delicious mocha latte, not nice new golden oil that I had just put in. I'm praying that it's only a blown head gasket and not something more serious like a cracked head.

If it ain't one thing it's another!

 

I have the same problem..
94 S-10 3.4L Vortec 6 cyl. Vin W
No engine codes.
Fuel in the intake manifold because of broken nut kit and/or regulator.
Replaced spider inj, nut kit, FPR, upper and lower gaskets {had to remove lower intake because of that darn torx bolt holding the lines in place stripping!}, then fuel filter and full tune up save the wires.

While i was in there i cleaned the egr 'hole' out a little better, but never took off the egr valve itself from upper intake. Could that be why the truck will start and run, but the idle is acting strange? It drives fine, but at a stop, the idle will drop and it will stall. My brother believes this has something to do with the timing, cuz i didnt mark the distributor properly and we had to TDC it. After reading other threads, im guessing it could be the connector that powers the injector. While you're in there performing the fun task of replacing nut kits or injectors, take a good look at the connector and read the other threads here for more info.

On a side note, be careful not to run the truck without checking out your oil after this mess. The first time replacing the lower gasket, i didnt get it sealed well enough and antifreeze got into my oil. Thanks to all posters for this extremely helpful thread!!