engine chug/hesitation..HELP!!

[odie301]

ok..i finally got a check engine light..but it was not so helpful. it came up as a P0300..showed as a "random misfire detected" which obviously makes sense because of the chugging.

My dumb question about it being a bad fuel pump is..wouldn't it start hard? it starts right away makes me wonder about a fuel problem. My other thought was something to do with spark, either plugs/wires or maybe a bad coil?? It runs great cruising down the highway just when you get on the gas enough it acts up

 

[Suburbinator]

When one of my O2 sensors crapped out, it did the same thing. Never threw a light or code either.
I don't have experience with E3's, but I only trust the OEM style plugs. I had so many issues with Bosch Platinums back in the day, I swore I'd stick to the basic replacement plugs.

 

[odie301]

I think i finally figured it out...one of the E3 sparkplugs was all messed up... due to "someone" dropping it when installing them. Yeah i goofed and dropped it..and it hairline cracked it. So when i pulled it out tonight it had cracked enough that the ceramic around the elctrode slid up and down on it. So after replacing it with a good one, and not dropping it, it seemed to run better on my way home. so hopefully that is it, i hope i didn't wreck my coil or anything

 

[saturday]

Odie - my 04 Denali was just doing the same thing. its the throttle body or the gas pedal. one of them is failing to transmit or receive the signals. seems random i know, but i ended up replacing both before i figured out which one was failing.


DOH!
dee de dee

2 hours late and i still had the wrong answer! tomorrow will be a better day.

saturday

 

[odie301]

i thought it was better after replacing my dropped plug..well part of it is better but it still does it. I notice it a lot more if you accelerate hard that any time it goes above 3k rpm it really starts to miss and pop. I was wondering if it could be an ignition coil that is going out?? is there any way to test them?

is there a way to test the throttle body theory out?

 

[saturday]

my mechanic was able to test the calibration between the throttle and the TB. i dont know how to, but i know someone here does. My problem was only during low RPMs though. would die just about anytime it idled. frustrating on mopac @ 5:30.

 

[pmbiker]

When my O2 sensor(s) crapped out my symptoms were a little different. I had rough idle, hesitation at cruising speeds and black exhaust (too rich) at WOT.