please help with p0300.

[svtfox]

ok so heres the deal ive been reading up on this now because im sick of throwing money at this thing! ok like it says i have a random misfire and i have replace all that i thought it could be with no luck. list includes

cap,rotor and plugs
fuel pump
upgraded spyder system
fuel filter
coil
tested ignition module and it was good
i also replaced lower intake gaskets
and coil pick up under dist.
replaced o2 sensors before and after cat


this is 97 blazer s10 and it seems to break up bad at low rpms like pulling away from lights and at shift points.......on the highway it misses but very slightly.
also would like to throw out there that the first time i replaced the coil and plugs that it went away for couple months but now is back???? so i replaced the plugs and what not again and nothing it just wont go away? so any input please.

[svtfox]

nobody?

[badasS10]

I have a 1997 S10 p/u with the same code. Random multiple cylinder misfire, correct? I ran some Lucas fuel injector cleaner and some 93 octane gas for a full tank, and disconnected the battery to reset the computer. So far, so good. This is what I'd suggest. I've also have the code reappear on cold mornings sometimes because I don't run a converter, and I have the O2 sensor from after the cat zip-tied to the frame rail, so it's not getting the heat from the exhaust that it needs to operate, although when the weather's right, it tricks the computer into believing the cat is working ultra-efficient, because it's reading pure outside oxygen, haha! I hope this helps a little.

[svtfox]

i just put lucas in it last night but have not drove it around just yet.

[00S104.3]

I had random misfire code on my 2000 once and it turned out to be the rotor. One of the little aligning prongs broke off and caused the rotor to jump around inside the cap. I replaced the rotor and all was well ever since.

[82-454]

I heard that the crank sensor is a problem with these motors. I've been having the same problem for about a year now. I only drive it on the weekends but it has become a money pit. On other car repair forums they talk about using only AC/Delco ignition parts to correct the problem. Let me know if you have any luck.

[amonos]

I have the same problem. Replaced cap, rotor, wires, and plugs. Ive double cheaked it all and erased the code 3 times. ON the 3rd time PO 160 also appered which is the MAP sensor. I havent replaced it yet but its a good posibility. The MAP sensor tells the PCM how much fuel and timming to feed the motor at the right time. As soon as I come up with $60 I will give it a shot and let you know. if you beat me to it let me know how it turns out:D