Misfire-bird

Hey yall
Got a dambed misfire that wont go away on 96 3.8L Fireburd. Heavy acceleration only. Changed plugs n wires, injectors serviced, fuel filter changed, pump works, coils ECM and vacuum checkt... nothin. Im getting older and mo' po'. Anyone have a similar issue- or know the answer?:confused:

Have you tried the timing?:grey:

sounds like you've spent a lot of money in your Bird just trying to find out what it is.if i were u,id take it to a shop.we took our '95 Grand Am to a shop and they ran it through this machine that tells them whats wrong with the car.if i were u id take it to a shop before spending more money and not finding out the problem.good luck!

3.8 mis-fire;
Questions... What after market accessories (remote starter, alarm etc.) are on the car? You said the fuel pump works, but do you know how much pressure its producing...45psi. min. at wide open throttle... Is the service engine soon light on? How many miles are on car? When you changed the plug wires was there any sign of rust or corrossion on coil towers(real common cause for mis-fire) is there any debris inside boot from air cleaner box to engine?(this will screw up mass air flow sensor)did you buy the $12.99 special plug wires from the local parts store?or did you use a reputable brand (ac Delco, Accel etc.)

I have the same problem, but my Bird is a 97...samething though. Service Engine Soon light is on currently, and it blinks sometimes too. What should I do to resolve the problem?:mad:

weve always bought GMs and the same thing happened with all of them.we always just thought it was a bad sensor

To respond to the '97 firebird problem, you said the service engine soon light is on and sometimes flashes, this means it is definately a mis-fire,the service engine soon light is on to tell you that the computer has seen a problem, and has stored a trouble code, in this case the code(s)will be 300 series mis-fire code.when the light is flashing it is warning you that a "catalyst damaging event" (i.e. mis-fire) is taking place, along with the poor performance of the engine, you may also notice a strong rotted egg odor from the exhaust,this is where the catalyst damage comes in to play.When an engine mis-fires, there is a large amount of unburned fuel released into the exhaust stream that the catalytic converter cannot burn off, which in turn causes the converter to overheat and melt down internally.So to answer the why; The most likely cause of mis-fire will be a bleeding plug wire, or a corroded coil tower. to check for a bleeding plug wire, start engine,using a common household spray bottle filled with water soak the plug wires and look for sparks coming off any wire, chances are you'll find at least one if not more arcing. If this turns up nothing, shut engine off,and inspect each plug wire boot(at spark plug & coils)for any signs of rust,or corrosion or for any thing in either boot that looks burned,also inspect coil towers, they should be nice and shiny(like chrome) if not replace that coil, as for the wires themselves if any "leak" or are burned, replace the whole set,and whatever you do,DO NOT USE CHEAP WIRES, YOU WILL REGRET IT IF YOU DO!



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Ok heres the run down, i have changed..... plugs and wire (ac delco)
three new coils, ignition mod. Code still is puttin out P0300 Multi/random misfire. Cat eventually plugged now is gone, (straight pipe) until problem fixed. When using a strong fuel cleaner the light comes off and is fine then goes right back to the same ol stuff. It starts hard and right after start the light blinks three times (misfire) I have had a injector service done at GM before the cat came off. worked for a couple days and then back to same. since the cat has come off i put new plugs for giggles and two plugs were fouled, I figure cuz the gas couldnt go ne where. i have tickled everyone proffesional oppinion and backyard ones too..... THIS IS CRAzy i am bout to put all new injectors in it. but that over 600... i have already put 600 in it. SOMEONE PLEASEEEEEEEEEEEEEEEee help. oh yea in case your wonderin 97 w/ 3.8

So your saying the GM dealer can't tell which plug is missfiring?
Rob

Come to think of it...my wifes old Bonneville (same 3800 V6) It was a 94 and it started doing this. I did the same crap as you...started replacing all this stuff. Finally took it to the dealer and they told me if was the ECM and it was misfiring but on all different plugs at different times. It was VERY frustrating. I replaced the ECM and it ran beautifully until we sold it late last year to a freind that is still driving now with 140k on it.

I had the exact problem you are having just about 2 weeks ago. When i slamed down on the gas, i felt a "thump, thump" and sort of a jerk like i wasn't even getting fuel to my engine. I took it into midas and they informed me of the misfire. They said there was nothing wrong with the engine but it was an electrical issue. They said one of the wires going to the cylinder was cut by a rubbing of some piece of metal. I didn't get the details b\c i didn't really care what caused it, i just wanted it fixed. So in other words they said, my 4th cylinder wasn't firing at all. So maybe your problem is electrical, not mechanical. I have a 99 3.8liter v-6 firebird. Hope this info helps

Once in a great while will it pull a #6 misfire but only on very occasion, after reseting the code it comes back to P0300 random multi. No one can tell me which ones it is...... how ever when i pulled the plugs last time there were two plugs more polluted than the rest. I drive it everyday some days its harder to start than others, and if shut off and started within five min or so (gas station) it fires like nuttins wrong. then comes the light blink blink blink coug coough cough... i have to rev it to round 2.5-3 to get the "crap" out of there it seems like.

after many nights of research.... P = powertrain 0= generic, not specific part 3= electrical 00= which cyl. the only thing soo far i havent replaced electrical? the ECM and is there a way of checkin this before replacing? that is a costly way but so are injectors. by the time i am done with this car its gonna be a million dollar car geeeeeshhhh also ne one havin problems with their driver power window? i took the door apart yesterday to inspect, i shot WD on all the bearing then WHITE Lith. grease them pretty good for a smooth operation, still only works in spurts but i can hear the motor "kick' on

Some one told me that when the window only goes up in spurts it's a sign of the motor going out. My dirverside window on my 97 was allready dead when I bought the car so it wouldn't go up or down at all. I just replaced it a few weeks ago and now it's fine. If you have to replace the motor don't get a dealer motor 'cause they don't have much of a warranty on them buy one from autozone they have a lifetime warranty.

and When using a strong fuel cleaner the light comes off and is fine then goes right back to the same ol stuff. I have had a injector service done at GM before the cat came off. worked for a couple days and then back to same.

I think you answered your own question. You mean you had the injectors flushed ? How many MI on car ? I would tend to think 1 or more injectors are plugged (If you get them replaced DO NOT go get cheap ones from Napa, AZone, walmart ect.... I have had these el cheapo ones go bad 3 days after installing them ! Go get AC Delco (Mail order whosale) bite the bullit :(

Well...
When it rains it pours... I was going to start working on my misfire problem, when all of a sudden I started hearing a thumping noise from under my car. I thought it was the exhaust pipe, cause it has done it to me in the past, before I had it re welded to the bracket, but alas, it was not. Yet anpther problem to add to the list. My center support mounting, which we all know holds up the 2 piece driveshaft, had broke and given up on me. So I had to take it out, and have a single piece driveshaft made, and put back in. Well, it wasnt all to bad. She picks up a little faster with a lighter shaft. Just thought you guys, and girls, would like to know.