Major Sputtering

Ive owned my Blazer for about a year and some months now, My dad bought it for me used, and the odometer was out, that was the only problem we could see. It ran perfectly and never gave me any problems.

But about 9 months ago it started sputtering a little bit, it was usually only just when i started it, while Id drive it sputter and feel like it was fighting for gas through most of 1st gear and a little of 2nd.

I took it to an autozone and had them hook the odb 2 up to it, and lo and behold the power was cut from it. So I took it to my uncle whose been a mechanic for years, and he tried to hook his little machine up to it and it wouldnt work. So now I cant hook a diagnostics machine or anything up to it. Ive replaced the rotor button, plugs wires all that stuff, the fuel filter, etc. Nothing works.

Now its doing it really bad. when I get into it and leave in the mornings, it sputters so bad it backfires, not a loud "BANG" kind of backfire but like a small one, and it constantly pops from out of the exhaust. It also kind of jerks when its doing all this, like the engine isnt getting any power or fuel. My uncle says its one of the sensors somewhere. That's not doing me alot of good. My fiances dad says it's probably the fuel pump. Well before going through all the crap to pull the gas tank off, I wanted to get as many opinions as possible.Thank all who respond.

Oh yeah its a 1998 Chevy Blazer LS i beleive. 4 Door 4.3L vortech v6. I have no idea whats wrong with it or where to even start on fixing it. My father just told me I'll probably have to just keep replacing parts on the engine and stuff until the problems fixed. I cant afford that and I cant afford for this problem to keep up.

What do you think about a plugged cat? Approx how many miles are on the blazer. I have seen similar situations result in a plugged cat, you could remove the cat inspect it and if it looks shity, hollow it out and reinstall and see if that fixes it. Doesnt sound like a bad fuel pump, but have you put a pressure gauge on it yet? As for the computer hook up, I havent ever seen that maybe someone else could touch on that one.

paxfam

I tried the cat thing, turns out whoever owned it before me took the cat off and replaced it with a straight pipe. So now I'm back to square one. I have no idea whats wrong with this thing, tomorrow the shops gonna try to hook up to a diagnostic machine. I'm hoping that works but, I beleive my uncles' tried before.


I had a freind today say it could be because of low compression. But I cant even begin to comprehend what that means.


Anymore leads as to what could be wrong?

If the cat is removed and its 98 with the PCM running the mixture that would confuse the crap out of it - there are three O2 sensors that monitor the exhaust. You need the codes readout to see so try another store to read.
Fuel pressure can be tested and see the many posts on that. Then electrical tests.

Just got back from the shop, somewhere between the fuse box and the connector under the dash theres an orange wire thats messed up somewhere, me and the mechanic got the diagnostic machine to work by screwin with the wires. I completely forgot to get the code, but it said something about catalyst, the mechanic told me it was the catalytic converter, but he didnt think thats what causing it, because he kept looking around.


He says the bulb went out for check engine light, and that when they do that, it can cause all kinds of weird things with the engine. I dont see how that makes any sense, but...ok, he said replace that, and try to fix the wire problem.



If that doesnt work, he said take the DGR valve off, (DCR? I forget) and put like a thin metal sheet basically, between it and the part it connects to, and it might stop it from sputtering so bad. I dont see how either of methods would work. the fuel pressure was either normal, or just a little high. (I'd been at this shop for the past 3 hours....so I wasnt in the mood to memorize everything).


Im gonna take it to an autozone or something, and get an OBD 2 hooked up to it and get the exact code to post for you guys, maybe you all can do something with that.

Keep reading this site. You'll find that the stuttering is a common problem for the Blazer. Did you replace the distributor cap? I suggest the Echlin brand you can get from NAPA. I purchased a cap from Autozone about 18 months ago and it shorted the center post and the no.4 together. Mine was bad enough to shut the truck down. The original style caps seem to have a design flaw. Check the routing of your plug wires also. The no.6 cylinder wire can rub through on the transmission dip stick and cause a miss, causing the computer to try and adjust for it, which then causes the other cylinders to missfire. When you replaced the plugs, I hope you didn't purchase Bosch. They don't work worth a crap on the blazer. Just buy a good set of platinums or straight AC Delco. If none of that fixes it, then a little more reading on this site will give you a lot of other directions to go.

Good luck.

Get a new aftermarket cat in there.

There has to be a cat in there or you will be screwin up the engine fuel trim values.

The cat will be a big source of your problem.

The O2 sensor system is the most important part of the emmission system and when it is screwed up, your whole engine will be screwed up and running like shit.

Get the cat in there, always fix the obvious and work from there.

I replaced the spark plugs with Autolite Platinums. I can replace the cat as soon as i get the cash for it. As for the distrubitor cap, the mechanic actually told me he got alot of cases in where the aftermarket caps would cause problems.


So as for now, I'll work on replacing the cap with the one suggested and the cat. Thanks to all who posted.