I am working on my s10 and cannot read with a code reader. I get link
so.... I have changed the plugs, wires, rot/cap, and have been told
crank sensors go bad on these guys. I also changed EGR cuase it was
heavily caked and sticking/worn out.
Any ideas are welcome. I hate to throw random money at it wildly but I
wanna fix it myself if I can.
She's running rough, has excessive exhaust stink like carbon stink.
Is this a W-code motor? L35 in the glove box or W in the 8th VIN
position. If so, you could have a leaking regulator/injector.
Replaceable as a unit, I pid under $400 for the injector and "nut kit"
(actually fuel lines from the back of the manifold to the injector
inside the manifold). If you have a fuel pressure gauge, hook it up
and see if it holds pressure overnight.
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 www.partszoneonline.com , 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 (Intake Manifold Tuning Valve) that's under it and peer
inside with a flashlight. You'll see the inside of the intake, I
think the injector is right there, but you'll be able to take a look
and see if the inside looks REALLY clean, or if there are puddles in
there at all, though you won't see much of the surface area inside,
you'll likely be able to see enough...
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
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 engine is shut
off? This one goes right to zero and when I gun the engine a little it drops down
to like 52 or 54 before going back to 56.
Mike Levy wrote:
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
1994 technology in it. It was one of the first 95's to come out.
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'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 www.lindertech.com for a discussion on the CPI unit and some
checks you can do. They also sell rebuilt units. Also www.s-series.org 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 www.acdelco.com Places to buy include
www.gmpartsdirect.com and www.rockauto.com. 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
The s-series.org site is great. I'm a member there. The forums are
actually up, but the main site is under re-construction. Forums are
http://forums.s-series.org I got my parts from
www.partszoneonline.com as I mentioned in another post. I went with
new parts because I was more comfortable going that route. My Haynes
manual says the unit is not serviceable, so I didn't want to risk it.
On Sun, 20 Jul 2003 01:10:34 GMT, "DonW"
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
I have some parts to take back (unopened) and some to pick up today and I may
jsut first check to see if I just dont have an injector stuck open.
Mike Levy wrote:
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.
Putting kit on now on a nice day. Long live the mechanic!!
Thanks to you guys!!
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.
Well, I found another regulator/injector assembly for $100 less and looked
like the Borg Warner one, same materials etc. so I went with that. Still 300
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
99.9% rock solid.
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