Automotive Question

[Darkness Productions]

I know that many of our members are heavily involved with automotive things, so I'll ask this here.

I've got a '93 Chevy Blazer 4x4 with a 4.3L V6. After driving it for about 30-45 minutes at a time, subsequent stops and starts are very 'painful'. IE, accelerating away from a stop is very slow, because pressing any harder on the accelerator causes the engine to bog down heavily, and, if kept that way, backfiring will ensue. This also happens when driving normally and pushing down on the accelerator to go into passing gear. It gets to passing gear, stays there for a moment, then bogs down and begins it's backfiring musical.

Does anyone have any idea about things I might check?


Thanks!

[TeeJay]

Originally posted by Darkness Productions
I know that many of our members are heavily involved with automotive things, so I'll ask this here.

I've got a '93 Chevy Blazer 4x4 with a 4.3L V6. After driving it for about 30-45 minutes at a time, subsequent stops and starts are very 'painful'. IE, accelerating away from a stop is very slow, because pressing any harder on the accelerator causes the engine to bog down heavily, and, if kept that way, backfiring will ensue. This also happens when driving normally and pushing down on the accelerator to go into passing gear. It gets to passing gear, stays there for a moment, then bogs down and begins it's backfiring musical.

Does anyone have any idea about things I might check?


Thanks!

You can try the 'paper clip' trick to read the codes from the ecu...
Google should help there...
My guess is the cat...
Backfiring thru the exhaust i am guessing...
G'luck DP

>>TeeJay

[IronBits]

Too much gas is the 1st thing that comes to mind...

Automatic choke stuck?
Float stuck in the carb?
Float might have a hole, or gummed up ...

Also check the accelerator plunger...

Does pumping the pedal help or make it worse or neither?

[gopher_yarrowzoo]

Hmm the time makes me think it's heat related in some way, since most modern cars are all electronic I think it maybe a sensor that's going faulty in the heat... but for sure it sounds like a carb problem, either not enough airflow or it's something of that ilk..
I'm gonna assume that this is automatic gearbox if so it may not be changing gear smoothly or getting confused but getting a computer on it won't hurt it will tell you the error codes and that will help a lot...

[Merlin45]

Sounds like the electronic choke isn't releasing all the way.


With the engine up at operating temp. Take off the airfilter housing top.

the choke butterfly should be streight up and down, if not and is at a angle then than is your problem. Need to replace the electronic unit on the side of the carb.

If that isn't the problem, check that a vac hose hasn't come off the base of the carb housing.

Does it smoke black when it does this?

If so too much fuel.

If no smoke.

Fuel filter is plugged

if not fuel filter, than fuel pump going out...........

Could even be a cracked distributar cap too.............

Go the cheap way first.


Check choke.......

check vac hoses on carb.......

check/replace fuel filter........

check distributar cap/ replace if any white or black carbon tracks on inside of cap, this indicates a hair line crack...... moisture is allowed to get inside causing misfires.

finally if that doesnt cure it, most likely fuel pump.



Hope this has helped......

[QIbHom]

Have you checked the transmission fluid levels? It probably isn't that, but it is a free and easy thing to check, and worth doing.

[LAURENU2]

It sounds like a timing or fuel problem
There is a old trick on checking your heads or timing
Take a playing card and hold it over your tail pipe exhaust with your car running
the flow coming out should be constant If it is not you could have cracked or pitted valve in you head Or a slipped timing belt. If this is all OK and the problem only happens when revving your engine It might be your vacuum advance on your distributer
To check your fuel
Hold a paper towel over your exhaust for one min look at the towel if it is black
you are running way to much gas
If you have FI your oxygen sensor might be bad

Good luck

[GHOST]

plugged fuel filter, sounds to me. happened to me many times.

do the cheapest things first.

[black_civic55]

sounds like something that happened with my dads truck. one of the cylinders wasn't firing correctly.