Sputtering under load

Tiny
THEMAILMAN
  • MEMBER
  • 2002 CHEVROLET BLAZER
  • 4.3L
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 179,000 MILES
My Blazer started with misfire the other day. Now, after it runs for a minute or two, when I get into the gas, it starts sputtering, huffing, and making a rattling/popping noise from under the truck. It gets worse if I run the A/C, and has started stalling out when coming to a stop. Figuring that it is a vehicle with almost 180,000 miles on it and still having the original fuel filter, I replaced it. That seems to have helped with the stalling, but the sputtering is still there. I am thinking the catalytic converter is clogged up and possibly that the screen thingy inside of it is coming apart (hence the rattling sound). What do you think?

The fuel pump is less than a year and a half old. The distributor is newer than that. The spark plugs are a few weeks old. I do not know the age of the wires, but they are not really cracked or worn looking and I do not see any sparks jumping when I checked outside in the dark. Check engine light has come and gone a couple of times, but is not currently on, and no codes show on the scanner.
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Friday, June 16th, 2017 AT 8:36 PM

7 Replies

Tiny
KEN
  • ADMIN
Hello,

I would replace the plug wires with AC delco unit and if the park plugs are not AC delco's I would replace those as well.

Here is a guide so you can check the catalytic converter.

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

Please let us know what happens, we are interested to see what it is.

Cheers, Ken

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Monday, June 19th, 2017 AT 10:53 AM
Tiny
THEMAILMAN
  • MEMBER
A while back, a mechanic buddy of mine told me about a trick using Sea Foam. With the engine idling, you take the vacuum line off of the brake booster and use it to suck the Sea Foam into the engine. Once the bottle is empty, turn the engine off and let it sit a while. Then take the car for a ride and drive it kind of hard. Believe it or not, it is running much better now, but still has the occasional miss and does hesitate with the A/C running.

As far as the plugs go, I did use the Delco ones that GM calls for. I'll be sure to get the wires done and see how it does with that.
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Tuesday, June 20th, 2017 AT 4:07 AM
Tiny
KEN
  • ADMIN
Please let us know what happens, we are interested to see what it is.

Cheers, Ken
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Tuesday, June 20th, 2017 AT 10:03 AM
Tiny
THEMAILMAN
  • MEMBER
So I hadn't touched it in a few days. Raised the hood today and took the distributor cap off. Looking at the even side of the cap, I see this gunk down in the where the plug wires connect. I think the plug wires are getting hot on that side and melting in there. Would that be because the resistance in the wires is too high? I went ahead and ordered new wires and creamed the contacts inside the cap.
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Sunday, June 25th, 2017 AT 7:23 PM
Tiny
KEN
  • ADMIN
Good find, please order AC Delco stuff, you can find it on Amazon for cheap.

Please let us know what happens.

Cheers, Ken
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Wednesday, June 28th, 2017 AT 12:12 PM
Tiny
THEMAILMAN
  • MEMBER
My wires came in yesterday. I put them in today, and it runs like a new car now. I swear it feels like I'm driving a Camaro compared to how it was. Funny thing is it finally threw a code this morning (before I put the plug wires in) for a random misfire (P0300). Anyways, thanks for all the help. I'll be back when something new pops up.
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Sunday, July 2nd, 2017 AT 2:37 PM
Tiny
KEN
  • ADMIN
Nice work, we are here to help, please use 2CarPros anytime. Have a great 4th

Cheers, Ken
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Sunday, July 2nd, 2017 AT 7:24 PM

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