Perfomance problem?

I have a 95 s10 blazer and I had a bad catalytic converter, I drove it for about 2 months with the bad catlyitc until recently I replaced it along with the muffler. My question is could driving with the bad catlytic messed up my engine in any way? My truck is running extremely rough and eating gas like crazy. I'm going to put new spark plugs and wires this weeekend. Should this fix the prolem its also putting out way to much exhaust more of a smell than a visble smoke. The next thing I was going to do was replace the O2 sensor and hopefully I can pass emissions?

Is this the 4.3 V6, Vortec written on top of intake?
W series...? If so does it start hard...run rich...smell more like gunpowder?
let us know...best wishes...

It is possible that the heat created by the exhaust backing up into the engine may have damaged the intake gaskets, or EGR valve. The Vortec engine showed up in '96. Ray

It's a vortec 4.3l V6. It starts ok, not great. THe major problem is when it idles while I'm at a stop light. It shakes like crazy and I'm getting the worst gas mileage. I replaced the spark plugs and spark wires and it seemed to help. I just bought a o2 sensor and will replace it soon. Could it be my fuel injectors? I ran a cleaner through it helped a little. Thanks for your help?

It is also a w series. what does that mean?

The Vortec was in 95 models-the W is the 8th letter in the VIN code which indicates the Vortec engine. View the Blazer/ S10 forum and you will find the same problem-leaking fuel injection parts in the plenum.

Bronco2...right on ...it is hard news to break to a person...but, we must tell the truth...and the internal fuel injection parts are not cheap.....but the problem idling and pooor gas milage...indicates this problem...hands down...Best Wishes...

Will the bad fuel injectors cause my smog to run rich, so it would fail the smog test?

Yes,it probably will fail. Also,the excess gas dumping in the system may cause engine damage.Repair this ASAP,and changing the oil and filter would be a good idea.

Thnaks for all your help. I've changed about everything I can think of and its still doing the same problem so its definetly the fuel injection system. Is the fuel injection system a hard thing to change out? I was going to go to a junk yard or buy a rebuilt one and chnage it myself? Have any of you guys ever changed out a fuel injection system?

I too am a big user of salvage yard parts...
But, the nature of this is that anything sitting for any length of time will has old gas stuck in the poppets...and regulator..and you would be paying money for the problem again...
This repair the CPI Unit with regulator is about $300. and the internal fuel lines about $40.
I tried to only use the new CPI but the internal lines were leaking as well...the good part of this is that with new lines and fuel regulator, CPI unit...your truck will run great...start great...and get the best gas milage ever...therefore saving you $$ on fuel wasted...

did not mention...I am sure I could not have done this job myself..and paid an honest mechanic $165.

You can do this-It is not a hard job.If you have ever replaced a water pump or a set of valve cover gaskets you have the skills. Buy a new F.I. unit and the lines,you will also need a upper plenum gasket.I would not use salvage yard parts on this job. Remember to change the oil and filter to-cheap insurance.

Yes when I got my truck running I notice the oil seems to have liquid/gas in it again...I will change it soon but is it OK to run in the meantime?

Gasoline is not a lubricant-you should change it ASAP.

It's a vortec 4.3l V6. It starts ok, not great. THe major problem is when it idles while I'm at a stop light. It shakes like crazy and I'm getting the worst gas mileage. I replaced the spark plugs and spark wires and it seemed to help. I just bought a o2 sensor and will replace it soon. Could it be my fuel injectors? I ran a cleaner through it helped a little. Thanks for your help?


My 94 Blazer is doing the same thing. Did you find out anything about yours?

Ok...

It's the EGR... Driving around with a bad cat ended up clogging it most likely... Pull and clean the egr with carb cleaner and a stiff wire brush. (use a new gasket to put it back on). Make sure your pintle is clear of carbon and moving freely... Run seafoam through the engine to dislodge the major carbon deposits.. Check your plugs for signs of carbon build up.. (probably should do a general tuneup after the seafoam):smile:

Hey Mjohn where did you get your CPI unit? Did you get it online? ALso some say that multi-port fuel injector and others say fuel injector(CPI) what's the difference? ALl i need is the CPI fuel injector, lines and the upper plenum gasket?


Thanks for all of your help. I called a mechanic place and they said that the vortec fuel injectors are know to go out and the whole fuel injector would cost 1,000-1200 just for the part itself.

CPI was used from 92-95, CPI is CENTRAL PORT INJECTION, CMFI was from 96-current... CPI is a batch fired injection system (all cylinders fired at the same time) CMFI which in general is a close cousin to CPI is fired sequentially...

do I NEED THE FUEL PRESSURE REGULATOR IT SAYS THAT THE WHOLE FUEL INJECTOR COMES WITH IT BUT COSTS ABOUT $500?

steven...you can do much better $$ at rockauto.com...the CPI Unit is 288. with 2 day shipping...it came to $321.22 and it is a AC Delco unit...a very nice part...the CPI Unit contains the fuel pressure regulator...gmpartsdirect.com is another place for parts but, you must wait 8-10 days? I think this is right...
Steven...Best Wishes on the repair...you will save the $$ over time just on wasted gas...as now I get between 17-19mpg... :o)

go to your Local Advance auto parts...275.00 and if it goes bad under warranty you can exchange it locally..That way you won't be out of a truck... Also no shipping charges...

seems you will be out sales tax tho...

a couple of bux in sales tax, vs being without your truck for up to 2 weeks while you send the unit back to where you bought it from, they test it, and either send it back or send a new one? I'll take local every time.

I replaced my fuel injection and it wasn't that hard but I recently took it to get it smogged and my HC ppm at Idle failed. IT passed before I did anything to it so it must be something I did. I replaced my spark plugs and wires but drove them with the bad fuel injector for about a month could they hav went bad. Help please.

Also thank you so much for helping me with my fule injection truck is running great at my gas mileage has improved immensly.

with the way your blazer is acting it is the fuel injectors, the strong fuel smell is coming from either a leaking fuel line o-ring, or more likely the fuel regulator has gone bad, and it is on of the easiest things to replace yourself, if it is just the regulator, you can call http://www.totalauto.com they sell a repair kit for the reg, but if it is the injectors , when you take the old "spider" off just mark which hose goes where. Price wise cheapest i have found is http://store.getgmparts.com/fj10453.html, $210.
If the EGR valve is bad you will get a service engine light, code 32

I just bought the CPI unit for my 92 S10 blazer. I got it from getgmparts.com. $225 with sipping (2Day Air) It came as a complete unit (spider) with a retaining clip and 2 "o" rings. I take it the "o" rings are for the incoming fuel lines, but I found a CPI "o" ring kit for 12 bucks at Orielly. What is this kit for? The poppets?

I just bought the CPI unit for my 92 S10 blazer. I got it from getgmparts.com. $225 with sipping (2Day Air) It came as a complete unit (spider) with a retaining clip and 2 "o" rings. I take it the "o" rings are for the incoming fuel lines, but I found a CPI "o" ring kit for 12 bucks at Orielly. What is this kit for? The poppets?

Remember to replace the nut kit as well when you do the injector.

Nut kit....What do I ask for at the parts store?

Upper plenum gasket. YES
Internal fuel lines????
Multi port "O" ring kit???
Nut Kit???

You go to the dealer and ask for the nut kit for your truck.

Only the dealer has them. The nut kit is the name for the internal line kit.

cool...thanks

Nut kit needs to be gotten at the dealer, just ask for it at the parts counter (not available in autoparts stores)

Whew. The work is done. It took just over 2 hours. Not hard at all. The hardest part was getting the old plenum gasket off and prepping the new surface. Total cost was $360.00.


http://store.getgmparts.com/fj10453.html
CPFI Kit (The main unit)............$210.96
Shipping...............................$14.93
Dealer
Upper Plenum Gasket.................$14.24
Nut Kit....................................$80.41
--------
$320.54

Auto Zone
Fuel Pressure Guage Kit.....................$39.21
--------
$359.75

I know for safety reasons you should have the Fuel pressure kit, but I spent 40 bucks that did little more than releive the pressure AS I screwed it on. The small amount of fuel that leaked out, did little more than dampen a sock that I had wrapped around the connection. I was disappointed that I spent the 40 bucks.

Thats all I needed, really not a big deal and fun too!

I read in the repair manual that the computer needs time to relearn how to control things after this repair as it is used to being disfunctional. The truck runs like it is brand new, but its having issues with shifting. I hope that this is only the computer trying to get a grip on things.

Any comments on this?

Thanks for all of your help guys!!!

Yea, the shifting will be a little snug and snappy for a while and then it will learn and soften up a bit.

It just takes time.

I hope you removed the carbon from the EGR passage while the top plate was off.

If thats the hole about the size of a quarter towards the front of the engine...Yes.

Is there a "Best way" to drive to help things get into shape?

If thats the hole about the size of a quarter towards the front of the engine...Yes.

Is there a "Best way" to drive to help things get into shape?

Drive normally. ;)

Seeing the tranny is computer controlled, it has to relearn as well.

Might want to get your transmission serviced if you have never done it.

Cool thanks.

I will still get the "service engine soon" light as it adjusts right?

Cool thanks.

I will still get the "service engine soon" light as it adjusts right?

Your service engine soon light is on now?

I had a 8 mile drive home on mosty interstate. Then I drove around the neighborhood a couple of times. The warning light came on after 10 mins or so and I turned the truck off for 5 mins and it wasnt on when I drove 2 blocks home.

Go to autozone and get the code checked.

Go to autozone and get the code checked.


K...Will do.

There is the CPI kits on E-bay right now for $199,GM parts too....check it out.

I just went to go to work and the truck will turnover just fine, but wont start. It fired a couple of times though only for a second. I changed the spark plugs when I changed the cpfi unit and have checked that they are still connected as well as the coil.

I jumped the codes and got a code 32 which the manual says EGR....Vacuum switch shorted to ground on startup or Switch not closed after the ECM has commanded EGR for a specified period of time or EGR Soleniod circuit open for a specified period of time. I have an linear (electronic) EGR.

Ah, take your EGR valve out and clear it of any carbon chunks. This is normal seeing you did clean the EGR passage and a chunk is holding the EGR valve open.

Also, get your timing set with the timing wire disconnected.

Ok..you seem pretty sure!! ;)

Well come to think of it when i cleaned the port the carbon did fall down into the hole. Probably all kinds of crap in there.
EDIT
I tried to call around for a new EGR valve just in case I need to replace it. Everyone needed the part number of the one that I have. I couldnt see the EGR part number while it is on the vehicle. Is it on the bottom?

Well come to think of it when i cleaned the port the carbon did fall down into the hole. Probably all kinds of crap in there.
EDIT
I tried to call around for a new EGR valve just in case I need to replace it. Everyone needed the part number of the one that I have. I couldnt see the EGR part number while it is on the vehicle. Is it on the bottom?

You won't need a new valve, trust me.

Just get a new EGR gasket and a bottle of TB cleaner and clean it and make sure the pintle is moving freely and reinstall it.

Then reset your computer and you will be set.

Cool...Thanks! I have three connections going to the distributor. Which one is the timing connector?

The timig connector is on your computer under your glove box.

It is a beige and brown wire.

Remove it from the computer, set the timing with a timing gun to zero. Reattach the wire, reset the computer by pulling the negative battery cable and you are set.

The timig connector is on your computer under your glove box.

It is a beige and brown wire.

Remove it from the computer, set the timing with a timing gun to zero. Reattach the wire, reset the computer by pulling the negative battery cable and you are set.


Rock and Roll!!! Thank You!!

*Cues Led Zepplin* :D

TB cleaner?

Ok. Took of the EGR and cleaned the hole the pintle seats in ( it was sticking but no sign of a big clot of carbon keeping it open) and the cavity as much as I could. It was very clean.also cleaned out the openings in the manifold as much as I could. TB cleaner, a little steel brush and 40 Qtips. The pintle moves freely now, as it was sticking closed when I pushed on it at first.

Put everything back together and tried to start it and nothing. Same as before.

Clearing the computer codes now (disconnecting the negative battery cable for 15 mins or so) and will retry. Man.

Yip, you will have to reset the computer for it to work.

Ok. Took of the EGR and cleaned the hole the pintle seats in ( it was sticking but no sign of a big clot of carbon keeping it open) and the cavity as much as I could. It was very clean.also cleaned out the openings in the manifold as much as I could. TB cleaner, a little steel brush and 40 Qtips. The pintle moves freely now, as it was sticking closed when I pushed on it at first.

Put everything back together and tried to start it and nothing. Same as before.

Clearing the computer codes now (disconnecting the negative battery cable for 15 mins or so) and will retry. Man.


No Go. Codes clear and not starting but turning over.

No Go. Codes clear and not starting but turning over.


I get a code 12 over and over which means the diagnostic system is up and running but the damn truck wont! :)

Check fuel pressure and check for spark at all the plugs wires.

Ill have to check it tomorrow night. Need a buddy to turn it over and also need the fuel pressure guage. Till then...