Ok... now a missfire

[JoeliusZ28]

Alright the lovely firebird that has been running absolutely peachy for the last few days randomly developed a miss-fire on me today. It will run on all 6 cylinders at idle and VERY light throttle, but beyond that it drops to 5 (or so it seems).

It has all new spark plugs.

Spark plug wires appeared shot, so i replaced them today... same problem.

I removed all three coil packs and cleaned the terminals.

Dielectric grease used on the coil terminals, coil connections, and plug wires.

Also tried unplugging one cylinder at a time, couldnt seem to get any indicative results with this method other than the coils appear to be functioning properly.


Starting to think I have a faulty injector, any idea what i should try next? I know of one solution and thats a for sale sign!

[jetice]

any idea of what you would sell it for?

[Gregs_gsxr]

check spark gaps

[JoeliusZ28]

any idea of what you would sell it for?

Now that I am impatient with it, it would be a perfect time to give me a lowball offer

check spark gaps

They were new spark plugs with significantly less gap than [what could have been] the originals I took out. And it ran fine on those horrible plugs.

[Gregs_gsxr]

I would still recheck the gaps too small or too big of gaps will cause an issue

[jetice]

Gah, if my dad didn't use our solus at home all the time, I could help a bunch of you guys out. I would see if anybody has a high-er end scanner that they could shut off each injector individually on. Real quick way to see if you had a bad injector.

[JoeliusZ28]

Gah, if my dad didn't use our solus at home all the time, I could help a bunch of you guys out. I would see if anybody has a high-er end scanner that they could shut off each injector individually on. Real quick way to see if you had a bad injector.

Yea i was thinking that. a buddy of mine has HPTuners that we could scan it with but he wont be home from school for another few days.

[94_LT1_Z28]

Now that I am impatient with it, it would be a perfect time to give me a lowball offer

I have 1 case of PBR

[MunsterZ28]

would a tech2 be able to shut off injectors? if so i could lend a hand joel ill b it i have very limited knowledge on how to use my tech2. havnt played with it much.

i know i atleast can pull up misfire graphs and tell you which cylinder it is.

[Gregs_gsxr]

would a tech2 be able to shut off injectors? if so i could lend a hand joel ill b it i have very limited knowledge on how to use my tech2. havnt played with it much.

i know i atleast can pull up misfire graphs and tell you which cylinder it is.

that would be a great start

[JoeliusZ28]

I have 1 case of PBR

Hmm, is it cold?

would a tech2 be able to shut off injectors? if so i could lend a hand joel ill b it i have very limited knowledge on how to use my tech2. havnt played with it much.

i know i atleast can pull up misfire graphs and tell you which cylinder it is.

Im not sure if it can do that or not. If so, the fridge is stocked with beer

[ezcruisn71]

Were any of the spark plugs ever dropped that you know of? If any of the plugs were ever dropped then you should check the ceramic on the spark plug very carefully for any cracks (run your finger nail around the ceramic insulator to help find the cracks). The cracks can some times not be seen at all! Disconnect the fuel injectors 1 at a time until you find the dead cylinder when the engine is under full load. Then check that cylinder for coil problems or a bad spark plug. Try replacing that spark plug with the old plug and see if the problem goes away. I have had this problem at work on Engines that we run on the dyno and it is usually a bad spark plug. If we ever drop a spark plug on the floor we will throw it out because 9 times out of 10 it will be bad!

[MunsterZ28]

Hmm, is it cold?


Im not sure if it can do that or not. If so, the fridge is stocked with beer

lol i work til like 4 tomorrow and am free after that, if you wanna get this diagnosed asap.

[Derek]

Good luck! Id make an offer but it wouldnt be more than the last asking price if a unknown demon is still lurking.

[sman]

Low fuel pressure? Pump cant keep up with the higher rpms? Clogged fuel filter?