coolmarocrzy

a friend of mine has had a few problems like this before.. once an o2 wire was burning on a header.. the other was the ignition module was going bad.. That ignition module is bolted to a braket right to the head along with the coil and maybe it could be getting heat soaked.. Just another theory.. but its worth taking it off real quick and running it to the zone to have checked, so you can rule it out if its not bad.

kainZ

jesus...

if fuel pressure is low, its the fuel pump
if o2 readings don't fluctuate or have no voltage, O2 sensors
if code 16 / 36 or tach banging around its opti
if hesitation/stumbling/misfire, its plugs or wires or opti most likely
if stalling it could be lots of things, so look at why it stalled, SCAN the codes, etc. process of elimination people, its not that hard and it doesn't need to involve buying parts.

if the datamaster scan says -40deg C or something crazy for engine temp, then its running rich because of the ECT sensor.. if not, save your ***cing 8 bucks... if it ain't broke, don't fix it!

don't be stupid people... problems have causes... watch house, do a differential diagnosis, and fix them, haha.. don't just throw parts at them before you even stop to analyze the situation..

note that winkle the moose has a head on his shoulders.. u should try thinking like that.. even 40 psi will be ok... but if its 12.. ur ****ed

KPZ-28

[QUOTE=kainZ]

don't be stupid people... problems have causes... watch house, do a differential diagnosis, and fix them, haha.. don't just throw parts at them before you even stop to analyze the situation..

Don't be so critical of me when you take your car to a dealership to swap out your opti. I didn't just throw parts at it trying to fix it, I replaced my fuel pump first when it started to stumble. It was 15psi and now my racetronix pump holds 43psi for atleast an hour and the vacuum line to the regulator is dry. At wot the pump drops to 38 psi, seems goofy to me but I hope thats normal. The car starts right up, runs great for about ten minutes then missfires throwing code po300 or if the outside temp is cool it runs great for hours. Let it sit overnight and the same thing happens again. Thinking its either fuel or ignition I start with the most common, new acdelco plugs, replace worn 7mm wires with taylor 8mm spiro pro making sure they don't arc or touch any metal in their stock looms, po300 again. I do the icm mod, same code again. I test coil, 5800 ohms seems weak since shoebox says it should be around 8000, replaced and po 300 code again. Parts guy says to replace icm with coil so I do and guess what, missfire and code po 300. I saved the opti for last with new waterpump and since its new it might as well get a new ect sensor for looks, my old one tested good but what the heck. In the meantime I noticed my elbow was torn on the bottom, so it got replaced with a new iat sensor.
So you now know we all aren't just throwing parts at random. I thought I had it solved after my opti swap, it takes longer now for the missfire to come, runs cooler and oil pressure seems higher when warmed up. Yesterday I got missfire and stalling with po 171 and 174 codes but no po300 random missfire. The yellow wire on my maf has 3.7 volts and 5khz when I snap the throttle. Speedy says it should be around 7k, so what do you think, keep the part buying bonanza going and get a new maf with a screen in it? What to try next, I unplugged my 4 o2's and it still missfired when warm (burned my hand in the process-real fun!) egr tested good. What about the fuel injectors or could the fuel pump heat up and loose pressure even though its submerged in gas? Sorry about the long rant, the only good thing about all of this is I'm learning something new everytime I work on mycar and my wife refuses to drive it!

WinkleTheMoose

Hmm....We could grab my brothers MAF that he has over in the garage, and put it on yours, and if it fixes the problem, you know you need a new one, cause its garunteed that his works.

KPZ-28

Thanks Sam, I'll take you up on your offer. pm me whenever it's convenient and I'll stop by your garage. I'm also going to borrow a fuel pressure guage from work and test my fuel pressure after it starts to stumble.

WinkleTheMoose

We have a fuel gauge here to if you end up not being able to get it from your house or whatever. So stop by if it you need to.

Sweetred95ta

Thank you!!!! I read the first 3 pages of this thing wondering how long this was going to go on.

The car is running like **** when it warms up because it is going into closed loop. In closed loop, the PCM is reading the O2 sensors and trying to get the car to an a/f of 14.7. When you let the car sit for an hour, it will start and run in open loop and will run a lot better, until it gets hot again and goes to closed loop. When you lean into the throttle, this is throwing it into "open loop" again and it's going to run good again. If you want to learn more about open and closed loop, search it. There is everything and more on this website.

Now, back to the problem. Unless you guys have large cams (with more degrees in between intake and exhaust duration, letting unburnt air by, making the O2's think that the car is lean and adding more fuel) I would say it is one of two things.

1. Temperature sensor: It is reading -40 (or some other wacked reading) and it's not letting the car adjust the a/f like it should.

2. O2 sensors: The computer can't get the correct reading from the O2's and it's making the car run horribly.

coolmarocrzy

see... it's guys on this site like Mr. I know everything kainZ & sweetred95ta that make me never want to ask questions or work with cars again.. Hrm.. I guess it must be nice to know everything.. but for those of us still learning here... why don't you back the F off with the attitude.. We didn't ask you to come in this thread telling us we're stupid. If you have a point to make.. or some experiance in this area of problems that you would like to share, then feel free.. Next time try not to be such a dick about it.

WinkleTheMoose

GOD BLESS AMERICA!!!!

Sweetred95ta

I wasn't trying to be a dick. The thing is, everything I've learned has come from reading threads on this site. Do you know how many threads there are posted on this same exact subject? That's probably why it went 3 pages before anyone gave any clear cut answers to the problem. I've posted in probably 10 different threads like this in the last month. I'm am totally willing to help and I have no problem with it, but the answers are out there. I was actually fairly nice in my post. I just couldn't believe it took 3 pages for anyone to shed some light on the situation.

It sounds like you need to stop listening to your mechanic too. He sounds like he doesn't know his a$$ from a hole in the ground. You may want to consider getting a aldl cable and downloading Freescan, so you can check your car. Instead of buying parts for it because they are reading a little different, check them out in real time and see how they are acting. I would have thought that unplugging the O2's would have solved your problem, but I don't know anything about OBDII cars. Just keep trying to diagnose things and getting back and posting the results.

Also, when people are talking to one another about borrowing this and that, it would be nicer if that was done in PM's so it doesn't ***** up the thread. It just makes it longer and more difficult to read.

WinkleTheMoose

Hey. Lets just stop with this post. We figured out what we think the problem to be. And as far as his mechanic goes, he has done most all of this stuff himself, and thats pretty dang good for being a first timer for most of the stuff on his car. He problem solved most all of the stuff that he replaced on the car, the car has 120k on it, and most of the crap is stuff, that need to be replaced in the first place. He knows what he is doing with the car, its just the stuff you wouldn't think would make a difference do. Drop this post. And leave it alone.

Sweetred95ta

I wasn't putting his mechanic abilities down. I got mixed up with all of the people that posted. One guy was replacing parts because his mechanic said to. I just had to go back and read over the post to figure out that it wasn't him. What did you guys find out to be the problem? Posting the solution will help people in the future that have this kind of problem.

LilJayV10

For the guru's in this thread. I am having the same problem on the 93 I am working on. I haven't thrown any parts at it yet, did swap out the ign module with another one I had. Any help would be appreciated.

http://web.camaross.com/forums/showthread.php?t=436613

kainZ

Everyone:

Listen, I'm sorry for dropping some f-bombs, that won't happen again; but, seriously, with respect to the rest of my post, you guys need to lighten up. I didn't call anyone stupid, I advised that you avoid being stupid, as in, in the future. Which, I think, will always be good advice. Besides, if I am giving decent advice about your car, why does it matter how nice I am in my post? Last I checked, this was the LT1/LT4 engine tech section, not the 'diagnose my car problems in yet another thread so i don't have to use the search button or my brain, but please do it without hurting my ego section.'

Yeah, that's a great attitude, quitting just HAS to be a great solution to mediocrity; I mean, everybody's doing it... and we all know that the more people who do something, the more correct it is.. By the way, none of us claimed to know everything. I said that you should be able to diagnose simple things like this by actually testing things and using your brain / reading the forum rather than wasting money on parts you don't need.

I brought the car to the dealer because I was at a friend's house, and we wanted to do fun things like watch midget **** instead of getting all dirty in the cramped engine bay of my car. When I brought the car to the dealer, I told them what was wrong with it, because I had already diagnosed it. In the end, the dealer sucked at life, and I ended up deciding to fix it myself; but, my laziness doesn't have anything to do with my criticism of people wasting their money on parts they don't need. The correct criticism for bringing your car to the dealer would be something like: "don't be lazy and trusting of incompetent people."

It would be nice if you posted the fix for his specific problem, so that other people could maybe be able to just do a search to learn what they needed to diagnose their problems, instead of invoking yet another 3 or 4 page dead-end thread... which, actually makes it harder for people to search for good information on their own.

Stuff that YOU wouldn't think would make a difference? The only things that make a difference are the things that logically COULD make a difference. Hence, with reasoning and testing, you can diagnose them before wasting your money on parts you might not need.

Sorry, I felt the need to apologize for swearing, and to clear the aforementioned things up.

ShowStopper540

ICM!!!, i had a friend with a 1995 TA, and his would do this exact same thing, it would idle fine cold, warm up, sputter and die, sumtimes we couldnt start it without waiting as much as an hour! the ICM has built in resistors and whatnot (as with most electronic ignition components), when the motor heats up, and the heat dicipates to the ICM, it fouls up, and soon enough will stop firing properly or stop firing all together, sumtimes waiting 5 or 10 mins will do the trick, the TA finally quit doing it all together, it wouldnt start at all, we replaced the ICM, charged the battery. fired her up and shes been running good ever since! i would replace my ICM if i were you, and if that doesnt cure it, my coil would be next.
NOTE:: Neither of these failures will put out a code