code po306 #6 cylinder missfire ???????

[skippy]

first off its a 1996 astro 4.3 vortec , the first vortec i've ever dealt with . it runs good except it has a stumble at idle & a little lagging on acceleration , but once its up & going its fine .
i changed plugs & wires today (what a major PIA !!!) the cap & rotor look to be brand new so i left them . the plugs were in for awhile Autolites ( for whatever reason ) but over all the # 6 plug was a little more carboned than the others .
but i still have the stumble & the code . I'm not sure where to look next . what else could give the computer a misfire reading ??????

no i don't have a manual yet , i will eventually but not this second . i was hoping someone here could point me in the right direction .

does this thing have seperate injectors for each cylinder ??? or is it like a throttle body ?
i know these questions may seem stupid to some but this is the newest astro i've ever had the pleasure of working on , my knowledge stops at a 95 system , which is different as you know .

so , thanx to anyone who can give me an idea where to look next .

[HPbyStan]

Yes, you have seperate injectors and I bet that's where your trouble is. The computer code for a misfire doesn't always mean the ignition is misfireing, it just means that that cylinder isn't pulling its share of the load.

[ihatemybike]

Green was doing the same thing. Put in fresh plugs, cap, and rotor with no change. You're suffering from sticky fuel injection poppets. GM has a TSB out for this. The solution is for them to run a solvent through the fuel system at your cost. Time for Seafoam, poured it into the throttle body and cleared the problem right up. Been two months since then and everything is going fine.

[skippy]

seafoam huh ???????? hmmmm , i can do that , thanx !! i hope thats all it is . how hard is it to get to the injectors & popets ???

[skippy]

Aaron , whats the best way to put the seafoam in to the injection system on my 96 ? do i just remove the aircleaner & spray it in through the mouth of the MAF ? or is there a vaccum line i should suck it in through ?

seafoam also makes an Deep Creep which comes in a spray can , would that be better to use ?

[ihatemybike]

Seafoam is not a spray. On Green I removed the engine cover, disconnected the air intake, and poured it into the throttle body.

[skippy]

ok thanx aaron . And deep creep seafoam does come in spray form thats why i was asking .And i've heard of people putting it in a spray bottle for different applications.

[ihatemybike]

Guess I having seen that version yet, probably cause I wasn't looking.

[crash]

deep creep is what it has on the can aaron. it's pushed as a penetrant/lubricant, but, it's the same stuff in aerosol form as what the liquid 'pour in' seafoam stuff. that info came right from our seafoam rep

http://www.seafoamsales.com/deepCreep.htm

[skippy]

Thank you aaron , that did the trick !!! no more code no more crappy idle . it still has a slight hesitation upon acceleration but its livable . hey for 200k mile van i'm not complaining , at leat it will pass NYS inspection now too .( with a SES light it wouldn't ) .

[ihatemybike]

Great to hear. It's amazing what chemical fixes can do sometimes.

Hesitation off idle. Hmmm, have you cleaned the throttle body?

[skippy]

Hmmm, have you cleaned the throttle body?

nope ,not yet , just bought the van a few days ago . i'm workin out the bugs now .

[skippy]

IT"S BACK !!!!!! code PO306

gonna have to call the dealer & see what injector cleaner thier using in the service bulletin .

[ihatemybike]

Might just have to do the Seafoam again, I've read where it took a couple times when the injectors were really bad. Good luck.