unsure of the problem

[firebirdjonny]

ok everybody i have a 99 firebird with a new intake and exhaust including a cat and cat back also including a o2 sim. My bird is not lighting the SES light but it is showing a posible miss fire off and on. I will be driving and just in xcerlation it will not go, just going puf puf and then go. Some times when i step on it it will go and other times it will not go. The plugs and wires are only 20,000 miles old if that. I checked above and below for burnt wires and no noticeable burns. Should i pull each off one by one and check them? I still have old injectors should i replace them? Or could this be a coil problem? I dont drive this car all the time just in the summer. I know that last summer i had to replace wire no. 4 because of a burn causing a missfire. This time it dont seem as bad as a burnt plug wire it seems not as drastic but seems to be getting worse. So if you have any suggestions let me know. I have done a search but wasnt satisfied with the results. If you wnat to b*t*h at me for a thread the same as before i can take it. But I just need some adivice.

[speedped79]

Re: unsure of the problem

ok everybody i have a 99 firebird with a new intake and exhaust including a cat and cat back also including a o2 sim. My bird is not lighting the SES light but it is showing a posible miss fire off and on. I will be driving and just in xcerlation it will not go, just going puf puf and then go. Some times when i step on it it will go and other times it will not go. The plugs and wires are only 20,000 miles old if that. I checked above and below for burnt wires and no noticeable burns. Should i pull each off one by one and check them? I still have old injectors should i replace them? Or could this be a coil problem? I dont drive this car all the time just in the summer. I know that last summer i had to replace wire no. 4 because of a burn causing a missfire. This time it dont seem as bad as a burnt plug wire it seems not as drastic but seems to be getting worse. So if you have any suggestions let me know. I have done a search but wasnt satisfied with the results. If you wnat to b*t*h at me for a thread the same as before i can take it. But I just need some adivice.

ju8st buy a set of taylor wires the fat red or blue ones i know people that have had em in their cars for years even winter driving with no problems plus they look great

[Camaro Dom]

Re: unsure of the problem

Well, my guess is a bad wire or two or a coil pack. Also, could be a plugged up gas filter and/or injectors. I know that on several people's cars including mine, the fuel sending unit slowly dies and **** like that starts happening. Check the air filter too, i have the ram air kit or w/e and it sucked up a bunch of leaves one time and i couldnt get the car to do anything.
speaking of air filters, if you have a k&n filter and recharged it b4, you might have put too much oil on it. what would happen then is that the oil would get sucked back into the engine, but it'll get all caught up on the MAF sensor, and throw the sensor off. just take it off and WITHOUT TOUCHING IT spray some self-dry electronics cleaner on the wires in it. i did that once, and i had to wait a good 1-2 seconds after touching the throttle to get any power. I'd get the rpms but it kept running lean and didnt go anywhere.

[Camaro Dom]

Re: unsure of the problem

hmm... how well does it accelerate when it does? like does it just seem to not have the same power that it did? can u get to highway speeds and keep there alright? if not it does sound like a bad cat, which is becoming increasingly more apparent to me as a common thing w/ f-bodies.

[firebirdjonny]

Re: unsure of the problem

Camaro Dom,
when its not misfiring it runs great. when i step on it with out a misfire it will burn the tires awesome. Ok when i have it on cruise control when it goes up a hill and shifts it will start to misfire, but then recover. but not always. when i get on it, it will xcelerate great but sometimes it wont. my air filter is good it is only 10,000 miles old new. if that old. I checked it and it was clean. If i am on a flat surface and at the same speed i dont notice any misfire. what i thought it may be was when i step on it, it was pushing a wire to ground out and misfire, but i didnt see any burns on the wires. If you have any more questions let me know. More heads are better than one. Thanks for the info. If you have nay more i will try to help your thought. thanks.

[redbird8628]

Re: unsure of the problem

dont throw parts at it, bang on the cat and listen for loose trash., try some F.I. cleaner in the gas, maybe sea foam it,, and check fuel press., if no go, then go to more expensive stuff, if it was ignition related, the ses light would come on, possibly a bad load of gas, how long has it been doing it?,

[firebirdjonny]

Re: unsure of the problem

it has a new cat. and has only been doing this for a month or so. not long. i have tried a F.I cleaner andno response. Has to be some thing else!

[Camaro Dom]

Re: unsure of the problem

how long has that fuel filter been on there? heres an idea... you gun it, and the pressure in the fuel lines gets u the acceleration, but going up a hill, you need more gas for longer and since the filter is getting plugged, its not keeping up with demand. hell, ya might as well.. they're like 15 bucks at auto zone and need to be changed every 20-30k miles anyways. it's just a thought, because i know i HATE trying to find electical shorts and stuff like that. FI cleaner wont affect a fuel filter btw so you have to change it anyways...
another thing... the way it sounds it very well might be spark plugs. i know its a pain in the *** but you might also need to take them out and look at them. maybe something is goin awry in the cylinder and either caused the plug to open up or shut closed, or crap is bridging the gap. to make ur job easier i'd check to see if a code registered so you'd only hafta take out one plug rather than the whole set. now that i think about it, i think that might be the problem. you might wanna do that first, and then the filter if it doesnt fix it. if those two dont work i think its off to the races with finding a short somewhere or a bad sensor. Good luck!