[Bigthreefan]

95 4.3 blazer 4x4 182,000 miles

in the last 6- months i've replaced:
fuel pressure regulator,plugs,wires,cap,rotor,fuel filter,temp sender & temp sensor,thermostat. the egr has been cleaned THROUGHLY along with the the plentum. also new CAT. & exhaust

anyway...... yesterday (saturday) it ran great. drove about 400 miles at 70-80mph most of the way. the check engine light flashed a few times

got up this morning drove about 40 miles highway 55-60 and some in town. still fine. check engine light flashed once

THEN had to run to the shop to drop some stuff off and to return a gift. when I get to the off ramp to the store. it starts sputering loss of power hit the brakes to slow/stop and wants to die. also SMELLS (rotten eggs)


O2 sensor? bam just like that?
I did replace the O2 about a year ago. but not after I replaced the leaking fuel pressure regulator.

cant pull any codes till tomorrow.

 

[MuddyS10]

cat is going, my diagnosis.

 

[Bigthreefan]

learn to read!! cat is less than 6 months old

 

[MuddyS10]

and what else would cause a rotten egg smell? nothing.

 

[bill 4.3l 5spd]

if the fuel pressure regulator was bad and it was running rich it could kill the cat fast. but yea thats the only thing that gives that smell.

 

[bill 4.3l 5spd]

and if u start to flame people it will kill how many replies ya get..

 

[Bigthreefan]

Ok Muddys10

I owe you an appoligie. it is the Cat.


took it over to the garage. sure enough Cat is glowin, RED

guess I just didn't want to belive it was the cat

SORRY :bowdown:

 

[MuddyS10]

's ok.

 

[rlith]

Well at least you found out what the end problem was before any major damage happened....Now you just need to find out what's causing your engine to run so rich that your cat is clogging up at 6 mos... Hows your CPI and Nutkit? Fuel could be leaking down and causing the richness...

 

[Bigthreefan]

if it was the cpi or nut kit. wouldn't it show up on the plugs?

pulled the plugs today ALL look good. (tan-ish color)


it runs "ok" when everything is COLD. but the warmer it runs the worse it runs


what the hell is a "nut kit" anyway?

 

[rlith]

It may not show up on the plugs... The nut kit is the inbound/outbound fuel lines inside the upper plenum..

 

[Bigthreefan]

that what I thought it was.

if the lines were leaking wouldnt there also be a hard starting problem due to "low" start up fuel pressure? but it does run pretty good cold but as it warms up it gets worse takes about 8-10 miles to get bad.

and if it was running that rich it should show up on the plugs? I'd think it would. the leaky pressure regulator sure did.

just asking

 

[rlith]

It doesn't necessarily show up on the plugs at all.... And you can still have a leaky nut kit or regulator and still have it start normally.... When you turn on the truck, the pump pressurized the system and keeps it pressurized to at least 56 psi (56-60 is what's needed) while still having a leak because the check valve on the fuel pump keeps it pressurized...So yes, this could cause you to run rich (one of the things) I'm not syaing it is in your case, just that it could be...

 

[rlith]

Also pull and clean the EGR and EGR port on the lower intake and run some seafoam through the system... This could be causing your idling problem as well (also pull and clean the IAC and IAC port) If for nothing else but general maintenance

 

[Bigthreefan]

did all of that already when i replaced the pressure regulator on 9/17/03. along with plugs, wires,cap,rotor,temp sensor,

the cat and exaust was done on 6/28/03

 

[Bigthreefan]

Ok the Cat is good.

It is now no longer glowing red after 5 min. but I did replace the O2 and clear the codes on sunday night.
and the muffler guy said the increased sulfer smell is coming from a rich condition. I think he may be right. And this would explain why it runs better after about 30mph

only drove it in town but it ran just like "normal". it has had a slight miss for about a year.

I am now thinking I may have a CPI "dripping" as far i I know it is the original with 182,000 miles

this could explain the miss and why it runs worse after it "warms up"

any imput?

 

[pyros46290]

i have your problems, but they are on 2 different cars. my 94 sonoma is on its second cat since ive put headers on and the cat thats on there now is startin to rattle just like the other one. thats the only problem with that but i cant figure out why its runnin lean/rich. the other problem i got is with egr but that is on my bravada. i replaced the egr valve and poured sea foam in the holes and it still ran like shit so i made an egr restricter and put that on and it runs great now

 

[Malice]

i got a 94 cpi and just had to replace my cat had the same prob runs great now but it smells like fireworks why is that

 

[Bigthreefan]

Even a good Cat. will have a slight sulfer smell. A motor thats running rich will have a stronger sulfer smell.

man the things i forget from auto tech.