95 s10 4x4 blazer rough run and stinks 135k

Sounds like the regulator or nut kit unless a failed check valve in the gas tank will cause this. I replaced my injector and nut kit myself. Took the better part of a day but those lines are tough to line back up at the back of the plenum, there are slots that a plate slips over to hold them in place. If you're opening the plenum, may as well spend the extra $40 to replace the nut kit.

Sounds like you're relatively mechanically inclined, you'll be doing this yourself? Before I did mine the most I'd done was replace spark plugs and fuel filter. I have a Haynes manual and it describes the procedure pretty well. I would suggest replacing the cap and rotor while you have the plenum off, it's MUCH easier to get to, but I see you've done that already.

If you finally decide to replace these parts and do the work yourself, I got mine from

, I had the parts relatively quick, it's a GM dealer so they're new GM parts. I also saved almost $210 compared to list price. The injector is part number 17113673 and the nut kit is 17112705. This is actually a common failure on these engines. How long has yours lasted? Mine's a 94 and had 101,000 on it when I replaced the injector parts this time last summer. I'm now at 111,200 with no injector problems yet.

As a last check, pull off the black/orange "Vortec" cover, pull out the IMTV (>Reading a manuual, I see the pressure should be 58-64.

oh yeah. I've had that Vortec thing off once recently. Its all built up in there with sludge. This was back when I had to change the EGR valve. The brakes practically caused an accident from lack of pressure due to that valve failing in one position.

I just got back from the local auto parts. They ordered me what I need fuel wise. I still have the crank sensor I want to put on and I think I know where it is after seeing anotther manual at the store.

How does your pressure behave? Dos the pressure stay up when the eng> Sounds like the regulator or nut kit unless a failed check valve in

I just checked whre the sensor shouldbe according to the diagrams and guess what? There's a place for it but there never was one there. Maybe this thing has a bit of

1994 technology > oh yeah. I've had that Vortec thing off once recently. Its all built up in there

I'd vote in Mike's camp on the CPI injector being the problem. Generally if you take the intake manifold tuning valve out (it's the round thing in the middle top of the manifold and the only thing with wires going to it) look down inside the manifold and if one side is wet then the pressure regulator is leaking. Also the 'plastic' lines or so-nut kit lines can crack and leak fuel. Look at

for a discussion on the CPI unit and some checks you can do. They also sell rebuilt units. Also is a group of s10 owners but the site is presently down. In the section on 4.3 engines there's been a discussion on CPI replacement and problems. You can get part number via Places to buy include and There may be other online sources. Worst part of the job was getting the retainer plate off the back of the manifold that holds the nut kit in place. You'll need a #30 torx head and 1/4" drive socket. Not much clearance between manifold and firewall. I change mine about 1 1/2 yrs. ago because of black smoke at startup, rough idle and sulphur smell. Truck now runs like new with 90k miles.

HTH

I hear ya on the EGR, had it clog up on the highway, re-engaged cruise after having to slow for someone in my lane with noplace to move to, going uphill, SES light blinks on. Got to my off-ramp and it was idling REALLY rough with no vacuum assist. GM fixed mine free under an extended service campaign, got a re-programmed PROM and new EGR out of the deal. I don't know how the fuel pressure behaves, I based my diagnosis solely on the symptoms of how the truck started and ran. It was hard to start 45 mins to 4 hours after running, because the engine was basically flooded, and running a little rough at idle. Mine hadn't gotten to the point of actually "cleaning" the manifold yet. Both symptoms cleared up right after replacing the injector. I never did and still haven't hooked up a fuel pressure gauge.

BTW, your truck is 1/2 OBD-1 and 1/2 OBD-II, 95 was a change-over year for the OBD system, it may not have all the sensors OBD-II computers need, but has more than OBD-1 computers need, and has a more sophisticated system. I bet you can't read codes out of the computer using the paperclip trick...

I went to that board you mentioned Mike. OMG!! I am rejuvenated!! I jusst wanna go out and tear off that intake manifold right now and not take any prisoners!!

I have some parts to take back (un> The s-series.org site is great. I'm a member there. The forums are

Dude, thats right where I am. sulphur smell, black junk all around the exhaust pipe. runs pretty good but rough and misses once in a while.

Looks like I'm changing that bad boy... better get ready for an all day affair. thanks for the links.

D> I'd vote in Mike's camp on the CPI injector being the problem. Generally if

Found entire kit at a local parts place (Borg Warner replacement) Talk about $$$$. Whew but...this is the fix. I can see how it would draw air/fuel instead of just air in the plenum when the regulator is leaking into the plenum.

Putt> ok...I'm into it.

Well, I found another regulator/injector assembly for $100 less and looked exactly like the Borg Warner one, same materials etc. so I went with that. Still 300 bucks though.(aftetr adding a gasket to the list)

It ran a little crappy at first but ran it a while and it has come around to be> Dude, thats right where I am. sulphur smell, black junk all around the exhaust