how can you tell when there bad?
My truck is running like shit hesitates, feels like its losing vacume, and blows nothing but black smoke.
When you unhook it and plug the vacuum line and it runs better.
which line the on that comes from the tank or the one that goes to the intake?
also went to pull it in the yard and my brake peddal got tight and i went to give it the gas and the motor would nt rev or nothing.
yeah u got a vacuum problem somewhere. best thing to do is find the vacuum lines and start pinching them off one by one. when it runs better, then u found the line where the leak is.
well i just changed the oil because it was do check the vacume lines which where all replaced when i got the truck from dawn.
No leaks. jiggled them pulled them off anbd on. still runs rough.
So i i checked the plugs and wires plugs are black. wires are like new.
Cleaned the plugs and throttle bodyand runs a little better and now blows white smoke instead of black. As well as throws a code off and on.
So tomorrow i will get new plugs cap and rotor.
But the white smoke wondering if my o2 sensor is shot hmmm. maybe fuel filter again?anyone got and other idears. The cat converter is 6 months old. and the fuel lines are new because i fought with a douch at advanced auto about replacing the fuel lines with rubber hoses.
this was to reply off pat, before your responce.
Probably with it running bad. It was just about to stall, and you used up the stored vacume in the power booster, using the brakes pulling in the yard. And then you noticed it didn’t have the power assist, when you went to use the brakes again? It might be related, might not be.
well i drove it for about ten mins and the brake problem didnt happen again. I dont know if i should have driven it longer or not but the truck didnt want to stall it just runs/ran like shit.
and this was me forgetting to say i drove it after i did everything.
yeah because blowing black or white smoke is a vacuum leak :bloated:
Agreed, white smoke typically mean coolant. Black smoke, oil.
right, BUT, im going on the fact that it idles rough, AND that there is no power assist from the brakes, that makes me think vacuum because they could both be caused by a vacuum leak. if it was just one of the two, well it could be a bunch of different problems, but since the truck is displaying both at the same time, it leads me to believe they are related. this may be going out on a limb, but the smoke could be caused from the vehicle running rich because of the rough idle? Code that is flashing could be a cylinder running rich caused by the rough idle? the fact that it changed from black to white confuses me a bit though. u sure its actual white smoke, not just because its cold out?
point im trying to make is dont tell me i dont know what im talking about when 1) you have nothing productive to add to the thread, and 2) it could be a lot of different things, im just throwing my opinion out there.
is it low on brake fluid?
is the smoke white, or is it just becuse its winter, dose it smell differnt?
black smoke is rich, blue smoke is oil.
Brian
oh and just because all of the vacuum lines are connected at both ends, does not mean that there isnt a crack, cut, or some other hole or something in the line itself. need to check that.
all the lines are new i replacced them and i did a check with warm soapy water and didnt see anything.
it is white smoke and smells a little rich. the plugs smell like strong gas. but they are dry.
also it is a 94 blazer4.3 vortec motor.
brake fluid is fine i just replaced a cou7ple lines a few months ago. all the wheel cylinders and calipers are good.
the smoke is probably because its running rich from the rough idle. hence why your plugs are like that as well. i would replace the plugs for sure. could check the fuel filter, although you said you just replaced it, but that doesnt make sense then if its running rich…only thing i can think of is check over everything REAL good it seems like u do a decent amount of off-roading with that thing, so mud, dirt, water, anything could have gotten somewhere it shouldnt, or you could have caught a hose or wire and ripped it off on something. id do a REAL good inspection of the underside, just to make sure nothing is ripped out, torn, or looks unusual. only other thing i could think of would maybe be the coil? but i would say eliminate all other possibilities first because the coil may be a costly trial and error sort of thing
ok lets take a deeper look then he also said that it could be a o2 sensor… hmm if thats not reading right the ecu is going to compensite for what it is reading.
soo first before you do a whole slew of things nyspeeds trainwreck says to do. i would pull the 02 sensor and give it a close inspection clean it off and you can put it back in or even go look at buying a new one if you are not low on cash or feel like replacing it just because its a 94 and a gm truck.
then you can look from there. have you replace the pcv valve at all? if not thats also a cheap fix alot cheaper then a o2 sensor but also deals with the vacuum line and the charcol canister.
your welcome that i added my .02 cents mike?
go look under your truck and name things other then the o2 sensors that can be ripped off… lets see:
- oil pain
- transfercase/ bellhousing
- drive shaft.
- maybe a cracked radiator but it doesnt match any of the problems listed
soo mike what can off roading do to vacuum lines that he has already checked out and is fine?
maybe the brake booster that pat mentioned? but i am almost positive that that would not cause smoking of the car.
OK … let’s all wake up to reality
Intake manifold gaskets people … vortec 4.3 … most likely taking out the headgaskets as we speak …