MY 95 blazer hell... code 175 system to rich ahhhhh!!!!!

ok heres the thing my blazer has a mind of its own. i changed the starter in it about a month ago. it was running a little funny then. like i knew it was running rich. i had the O2 SENSOR changed in it about a week in a half ago. after that the problem of it sputtering and vibrating at take off, and really bad gas mileage, and idleing horribly contunied also ONLY sometimes when i went to start it it would make a noise like i turned the key when it was already on. only it wasnt. i also went to advance autoparts and had the engine light seviced the code was "PO175 system to rich." they informed me that if the person installing the sensor didnt rest the computer (by takeing the cables off the battery) that it wouldnt take, so they deleted the code and it started to driver better?! only when i was idleing for more than 5 mintues the engine light came back on and the sputtering was not as lound or hard but still therer, it sounded like it was missing. sooo, i went home and took the cables off the battery and the problem went back to the way it was before the code was deleted. I was told that if i take the sensor out and spary it with carb cleaner that this will fix it? but im not sure if that is the problem any more if some one could help i would really apperciate it.!!! :)
thanxs liz

1995 blazer 4.3 vortex 4x4 in need of alittle help :)

Check the fuel pressure at the shrader valve. Look for the fuel rails going in to the back of the upper intake plenum. Post back your fuel pressure. You're supposed to be in the 60-65 range, I'm guessing you'll be lower.

Take off the IMTV valve and look inside the intake manifold. Shine a flashlight in there and see if you can see any puddles of fuel. If you're lucky it'll be completely black and carbony in there. My guess is you're one of the many unlucky 95 owners with a bad CPI. You may need to replace the CPI + Nut kit. Post back if you see puddles on the passenger or drivers side. Drivers side indicates a leak in your nut kit, passengers indicates a leaking fuel pressure regulator. If you replace the CPI I HIGHLY recommend doing the nut kit too (its not very expensive, and very worth your while)

Ever done a tuneup?

How does your oil look? You don't want to drive around with gas in your oil.

I hate CPI's....worthless. Good thing GM put out a recall on them. Get 'em changed over to CPSI by the dealer for free now......WEEEEEE!!

I hate CPI's....worthless. Good thing GM put out a recall on them. Get 'em changed over to CPSI by the dealer for free now......WEEEEEE!!

Ummm...no.

CPI's were never dealer swapped out.

ok heres the thing my blazer has a mind of its own. i changed the starter in it about a month ago. it was running a little funny then. like i knew it was running rich. i had the O2 SENSOR changed in it about a week in a half ago. after that the problem of it sputtering and vibrating at take off, and really bad gas mileage, and idleing horribly contunied also ONLY sometimes when i went to start it it would make a noise like i turned the key when it was already on. only it wasnt. i also went to advance autoparts and had the engine light seviced the code was "PO175 system to rich." they informed me that if the person installing the sensor didnt rest the computer (by takeing the cables off the battery) that it wouldnt take, so they deleted the code and it started to driver better?! only when i was idleing for more than 5 mintues the engine light came back on and the sputtering was not as lound or hard but still therer, it sounded like it was missing. sooo, i went home and took the cables off the battery and the problem went back to the way it was before the code was deleted. I was told that if i take the sensor out and spary it with carb cleaner that this will fix it? but im not sure if that is the problem any more if some one could help i would really apperciate it.!!! :)
thanxs liz

1995 blazer 4.3 vortex 4x4 in need of alittle help :)

Remove your Vortec nameplate on the top of your engine.

Remove the round valve underneath it.

Take a flashlight and look down into the upper plenum and looks for golden silver washed spots and pools of fuel.

It should be black is there is no leaks.

You didn't get the memo? I had my '98 1500 W/T with a 4.3 and my '99 blazer both changed out, free.

This is a 1995, different injection system.

LT is describing the sequential injection system.

Unfortunately LT and I have both had to replace our CPIs out of our own pockets.

Yip, 1995 CPI injection system is not covered under any warranty.

Well, i guess i got free parts and labor then..:-)

your 98 and 99 have the faulty spider unit on a sefi system that got changed out free, not the batch fired cpi

So when did they change over from CPI to CPSI?

in 97, and i beleve it went till atleast 05

1996 they changed from CPI to CSFI.

Yip, 1995 CPI injection system is not covered under any warranty.
not even a recall. its an expensive thing to out-of-pocket. i guess instead of recalling it and loosing money, they switched to CSFI with a throttle body

Too bad really, it was a good design.

Too bad really, it was a good design.
it was. i've heard and read that the 94 4.3cpi had higher compression, like 9.3:1, then it fell to 9.0:1 in 95 but was still rated at the same 195hp. its a good engine when its running right.

It is and the torque curve is what makes it better than any other 4.3L injection system.

When the upper plenum IMTV valve opens up at 3000rpms, the torque peak is shifted to the higher rpm range.

So you get torque in the low and the high rpm range.

Pretty ingenious really........until they installed a shit injector from the factory......idiots...

It is and the torque curve is what makes it better than any other 4.3L injection system.

When the upper plenum IMTV valve opens up at 3000rpms, the torque peak is shifted to the higher rpm range.

So you get torque in the low and the high rpm range.

Pretty ingenious really........until they installed a shit injector from the factory......idiots...
GM and their brain farts :rofl: :rofl: :rofl: :rofl:

did you do a tune up?