another member on here was having a problem simiilar to mine (just worse). So, i'm trying to narrow things down a little so i can fix the problem and take my car on a 200 mile trip to school in the next two weeks.

When the car is cool, everything runs fine, seems good, etc. Once the car warms up however, everything goes to hell...it's not necessarily an open closed loop situation however (atleast it doesn't appear to be) the reason i think this is i've had it run well at 210* for a while, then it'll start acting stupid (go a little crazy on me), from there on out, leaving the line = sluggish performance, muffled backfires (from both sides of the engine ... least it sounds like it ), etc. Once the car starts moving and isn't accelerating everything seems fine. I had a problem like this once before related to an bad MAF, so here's the Q, where's it coming from?

More than a month ago i got a lean code from the O2 sensor (the trip home from school) so i'm suspecting it could be a possible culprit, and since i haven't been driving the firebird for my daily (until recently, so i can get it tuned for school) i hadn't really noticed anymore codes. Other things, I did a 4th gen dash swap which is still in the process of finishing up, the last piece of the puzzle is swapping to an electric VSS in tranny so i can have the speedometer to work, after that i'm done, so, is not having a VSS signal causing me these issues? for some reason i'd think not, as there are other people on the boards who have had no VSS or speedo working, and haven't expressed any "driveability" problems. Is the problem related to my possibly deffective o2 sensor? Also, the idle is rough, and there's a lope in the exhaust (no rich smell though) the lopey exhaust only happnes after the car has been run and is running like crap ... it wouldn't bother me, if the car was supposed to sound like that. lol. anyone got a clue to these probs?

 

Go out and spend the $20 on a new 02. If it's not the problem, at least you will have a new one on there and can eliminate that as a suspect in the troubles.

Have you tried resetting the ECM? Might want to do so after replacing the 02 sensor.

 

no vss should no be affecting it. try changing the O2 sensor and check your timing to make sure everything is good there. if you're still having problems, let us know.

 

Check timing... I'm going with bad coil or ICM, myself

 

ok, i'll get on the timing...will probably do the O2 sensor also since i did get that lean code.....on the coil i replaced it this past winter because the stupid car had a horrible hesitation issue, and the one on there was the original and kinda lose in the bracket, i went w/ factory replacement. The ignition module is also new, it was replaced 3 weeks ago because the old one had faulted, and the car wouldn't just hesitated, it'd die, shut off and on, and then wouldn't restart in the garage until the car had cooled down (or sat overnite)......and yes, the new one has the silicon lube on the backside, made sure to goop it all up too, didn't want it failing early.

I'm suspecting O2 sensor, but only a little more time will tell....maybe i'll try to replace that tomorrow, it's a pita, anyone have a good method for getting those thigns out?

 

To get a bad older 02 out, mine was pretty well stuck. I cut the pigtail off (going to replace it anyways.. what do I need it for?) stuck a 7/8 deep socket on it and attached it to my ratchet. After attaching a nice long extension handle (read as: cheater bar) and using a BFH, the thing came out with no probs. But that was after having soaked the thing in PB Blaster for two days.

After you get the old 02 out, save it and clean up its threads, since you don't have a tap the right size (most of us don't) and thread it in and out of the hole until you can put the new one in by hand. The new one SHOULD have anti-seize already on it, if it don't, add it! This saves tons of headache later...

DON'T FORGET TO KEEP FINGERS AND DIRT AWAY FROM THE END OF THE NEW SENSOR THAT INSERTS INTO THE Y-PIPE! CONTAMINATION IS A BAAAAD THING!

 

One thing everyone should remember: Ignition problems tend to occur when the engine is HOT. Also, backfiring would lead me to question the ignition system. You could easily have something simple like a bad plug wire or an arcing plug wire. You say it runs fine once you attain speed and start cruising......the ignition system is under severe load when you accelerate, but the voltage required to jump the spark gap at cruising speed is much lower.

And don't say "oh my wires are brand new". My car ate a #3 wire in 2 months so I had to put a heat shield on it.

 

i had a wire come apart after a week, and definatly do anti-seize

 

that's very true, i was going to tune it b4 leaving for school anyway, we'll see what fixes the troubles.....hopin i'm not going to rebuild the ignition system again as i've been there, done that.

 

alright peeps, on the timing...bought a light (my old one got rained on (and in apparently)) and i decided that i'd check the timing out, expecting it to be close since i had it set last semester at school because the car was runnin horrible. Well, w/ the EST plugged in the timing was sitting at 16 and had a little bounce to it (i'm assuming the bounce was from the engine not having the "best" idle in town) and i said "not bad for advanced timing especially w/ the EST in." so, i hit the throttle, and the timing steadied out, staying close to 16, then dropping to 14 once, and then raising back up, seemed pretty good. So, i unplugged the EST and gave the same test for base timing, and...umm, whoa. So, the base timing on this engine is set at what appears to be zero degrees, i didn't have a flashlight to shine down in the hole so i could read it well, but it's waaaaaaaaaaay the hell under the 10* mark that the shop made when setting timing, infact it's in the little groove cut out of the timing plate, so i'm curious if the shop set the timing, but set it with the EST plugged in. (it was a kid who was working there), so now i'm waiting for the car to cool some, and i'm going to loosen up that dist. hold down and set this better....hopefully that'll solve some of the rough running problems i have, even though i don't know if it'll solve the backfire....we'll see about that when i toss in the o2.

 

so how much difference can base timing make when driving a car? just curious since the computer will advance the timing anyway.

I'm askin the question but not doubting my result, i didn't notice the backfire or hesitation issues, even after warm, and the car had raped ape syndrome when it wasn't burning up in temp (210*+)and had decent performance while hot....i'm not saying this is a guranteed fix, however, i do believe it's helped things out a million times....oh, and two days ago i stomped the gas at a stopsign where traction issues can exist easily, and the car simply went forward. Today i did it on a nicely paved road and i had the tire spinnin, came to that same stopsign i was at the other day, slammed the pedal down, and she gave a nice hoot and hollar of a burnout.....some of the ***** are back, and i'm slowly feeling confident about this car again.

 

Hell yeah to that! That way ALWAYS works!

Don't forget, the computer advances the timing OFF OF the base timing. (That's why it's "base" timing.) So if the base timing was retarded, the computer can't advance the timing as far as it should be able to. In fact, if I have my timing light on with the EST bypass still connected, the timing shows way off the scale.

 

well then, that should explain my hesitation, stumbling, maybe my backfire but we'll see on that....just got back from another 20 minute drive and i'm in love w/ the car again....and that's scary cause it's been so long since i've loved this car.......I'M LOVIN IT (the new thirdgen slogan)