Ok so we got the blazer (92 s10 4.3L CPI 4wd - 202,000+ miles) running yesterday and thought it'd be a good idea to change the oil and filter since she's been sitting up for two years. (A new fuel pump, filter, and strainer has been put on).
When the oil was drained it was VERY thin and reeked of gas. Read a good bit about certain treatments and changing the oil several times before the gassy smell will actually be gone. Went ahead and put new oil in her and changed her oil filter. Put in an oil treatment which will also seal the rings (in case they are possibly leaking). My neighbor, who tinkers with cars, said that he didn't believe it was the rings. Drove it down the road this morning and it pops pretty regular. My questions are:

If the rings are bad, wouldn't it smoke?
Would changing the FPR and Relay stop the gas leaking into the oil - AND the popping noise?
And if necessary, where can a CPI be purchased?

Any advice and suggestions would be welcomed. Have got to get on the road because it's the only vehicle our family has.

 

Its not gonna be the rings. That popping is the misfire on 3 and 4 cause the plugs are soaked with gas from an internal leak. You probably have a leaking CPI unit, its so common on these engines, I think we have all had to change them. You can get one from injectorwarehouse.com for under 300 bucks and it comes with a FPR, or even take your chance on a junkyard unit. Do a forum search for CPI LEAKING and you will get a plethora of information from us here. Ive got a video on my youtube channel of how to check the pressure is you like, my screen name is OHSOOOFLY on youtube. You will need to find out what part is leaking first, so take the upper plenum off and turn the key forward so you can see where the gas is spraying from. Its either the nut kit (the 2 lines), the CPI itself (not likely) or the FPR leaks (the round thing on passenger side). Dont bother changing the oil yet though... I would have dumped the gassy stuff out and poured my last oil change back in till it gets fixed...

 

Pull the plenum and take a look. If the driver's side is wet and clean, it's the 'nut kit' (fuel pressure and return lines). If the passenger side, it's the fuel pressure regulator. I'd do both, simply so I wouldn't have to pull the plenum again.

The nut kit's about $55. The FPR is about $40. The upper plenum gasket is about $12.

If you do the test ohsofly mentions above, make VERY sure NOT TO START THE ENGINE. If you do, you'll have a whole 'nother world of hurt to fix (you'll light the sucker on fire). I'd pull the coil wire, personally.

The pic below is from my Astro, same motor and same year, so it's backwards (taken from inside the van) - the right is the passenger side, the left is the driver's side.

 

The cheapest CPI unit i found, reman, was from O reilly's autoparts $177.00 I am still am freakin amazed they can put $177.00 bucks in to these units.

 

Thanks for the advice. Leeann, your picture was very helpful. The plenum was pulled and did the check per instructions. Found a spring leak (still streamed out even after the blazer was turned off). I've circled the hose that had the leak. Is this what is meant by "nut kit"? I'm not too familiar with the terminology, sorry. Also, how would this part be replaced?

 

Honestly, if you want to do it the easier way, purchase the LIM (lower intake manifold) and some coolany, and just remove the Lower intake as well. Its possible to remove those 2 lines with the intake on the engine, But I couldnt figure out how so I removed mine and did it on the bench.

The lines undo at the injector unit by removing that clip like the letter U and pulling the lines out of the injector. Then you undo the fuel lines outisde the plenum from the lines that are leaking (hard part) then you press those 2 lines out toward the back of the motor (also hard) and reinstall the new stuff. Its much easier to do this all on the bench. At least in Leanns astro there is no firewall getting in your way.

 

Yes, that is the nut kit - both of those nylon lines. There's a metal clip that slides out to remove them from the injector and, on the outside of the plenum, a Torx screw and a bracket that holds them tight to the plenum. They just unscrew from the fuel lines.

 

Thank you ohsofly. And you're not kidding on the hard parts. That firewall just HAS to be there huh? As a gal I don't like tight places and my husband doesn't like working with them either. Got everything else off except that bracket, because of where it's at. Thanks for the pix LB, visuals really help alot, especially for those of us with NO patience what-so-ever. Once we get this baby going we'll be able to finally start putting money into cosmetics (the FUN stuff, I can't wait). Thanks for all of your help, you don't realize how valuable it has been to us.

 

Glad I could help

 

Oh ya, and make sure you get the injector harness to replace too, its like 8 bucks, and if that runner thing is not really tight still, and you get black on your hands when you touch it, then replace it with an oil resistant new one cause it will strand you some day if you dont.

We got another car working on gal - cool