JAWZGIRL

I am having problem wit 90 camaro rs , this problem has just started over the past year and I have been changing everything to fix it and just seem to get worse.I had to change timing belt ,egr, dist cap, rotor, o2 sensor,coolantsens,tps,cat,map,and fuel filter many other things lets start out with problem now ,will start fine will idle but cant drive , it first started out as I could not accelerate fast as car would bog down but let off gas it would come back up now I cant accel. at all wont go. trans shifts fine when running . also at times when you start it it idles ruff but other times its fine. I need help asap I have no more ideas. also I pulled codes and heres what they are. 33 MAP sensor circuit error (signal high indicating low vacuum),44 Oxygen sensor error (lean condition indicated),45 Oxygen sensor error (rich condition indicated) also new wires and plugs

Stephen

iTrader: (12)

Considering the error codes you got, have you replaced the O2 sensor? Or at ;east checked it out? Maybe borrow a buddies known good O2 sensor, since they aren't real cheap to see the results?

JAWZGIRL

o2 sensor has been done that was first thing I did with those codes, just seems to be getting worse now cant drive car as it will not accelerate. some one said distributor but I cant see why those codes would flash if that is the problem, any other ideas

sofakingdom

iTrader: (1)

Sounds like your fuel pump is dead.

What's your fuel pressure?

JAWZGIRL

fuel pressure is 44, I was told thats what it suppose to be ,also dont think it would throw those code for that either. I cleared my computer and with in 2 days those codes were back ,anybody out there think its my coil pick up

sofakingdom

iTrader: (1)

What is the fuel pressure WHILE IT'S IN THE ACT OF SCREWING UP?

Tape the gauge to the windshield and try to drive it, and see what it is WHEN IT SCREWS UP. Getting the reading while it's running right, like sitting idling, doesn't tell you a thing about what it's doing all those other times.

No it's not your pick-up coil.

Don't worry about the codes until you get the fuel delivery problem sorted out.

JAWZGIRL

thanks for getting back to me , last week I did the pressure during idle it was 44 , then with throttle went to 55 , the being of this week it would start the run really rough at idle then dies out, will not accelerate and as of yesterday car start then dies out right away wont stay running anymore

JAWZGIRL

also when I could drive it, it would bog down if you pushed the throttle to much but if you push it alittle it would get up to speed, the rpms would be low sitting at idle and rough

sofakingdom

iTrader: (1)

What happens is, the fuel pressure is FINE as long as the engine's demands for FLOW are minimal; but as soon as it tries to flow more fuel, the pump can't keep up.

Kind of like your bathroom sink would be, if you turned the little valve thing underneath there until it was almost closed: there'd still be 60 psi or whatever at your faucet when the faucet is off, but when you turned the faucet on, only a trickle would come out, and the pressure would drop to ZERO.

That's why you need to measure the pressure WHILE IT'S SCREWING UP; because at THAT time, whatever is going wrong, is going wrong. When the car is just sitting there acting normal, then whatever is screwing up whenever it screws up, ISN'T; and you're not going to catch it in the act. Just like the bathroom sink: if you put a gauge on it and only looked at it when the faucet was shut off and you saw 75 psi or something, you'd probably think everything was OK; but look at the pressure WHEN IT'S SCREWING UP, and you might see ..... 5 psi. Wouldn't be hard to deduce that you have a pressure problem when FLOW is required, and maybe something somewhere has a blockage or something.

Don't argue, just TRY IT. Whaddya got to lose? Either it'll help you figure it out, in which case, YOU WIN; or it won't, in which case, you know you can rule it out. Either way, you learn something valuable.

JAWZGIRL

wow ok I will try it tomorrow just going to be a bit hard since car wont stay running anymore . will also try to flash computer to see if it will let car start and stay idle and maybe drive a little

ASE doc

Sofa kingdom is on the right track here. The progessive nature of your problem sounds very much like fuel delivey. If you cannot verify a drop in fuel pressure, perform a pump volume test.

As odd as it sounds, a pump can produce sufficient pressure to pass a pressure test and still not provide enough flow to supply the engine. I have been stumped by this before when fuel pressure read fine, even driving and when the system would go lean. Replaced the restricted fuel filter and problem was solved.

HawkZ28

iTrader: (2)

X2 on the filter, and volume supplied.

I also had a similar problem caused by a relay, too. It was sporadic and the relay would overheat, and not supply enough voltage. Something that you should always replace (IMHO) when you do a new pump- I once had a bad relay that burned up 3 pumps before I figured out it was a $10 relay causing the pumps to die prematurely.

ASE doc

On certain vehicle lines, GM requires replacement of the relay with the pump. There is a TSB on this for affected vehicles. I definitely think its a good idea on any vehicle. Not bad either to check power supply voltage to the relay.

JAWZGIRL

ok so I went and just replaced the fuel pump myself (girl that is) and cleared codes drove it around a while and it seemed to do better , then while sitting rpms seemed low so just gave little gas to bump up, next I noticed car using a bit more gas (no leaks from work I did) went to accelerate more and car bogged again car now throws code 45 o2 rich any ideas this time .

xch3no2

Well you list the converter as replaced sooo might there be another exhaust restriction, squished or plugged pipe?

GM parts used (not generic from aftermarket) for EGR replacement on these can be critical but I don't think the problem would be so severe.

With fuel pressure good,
My other & best idea would be injector filters/screens clogged.
.

rgarcia63

A new fuel pump won't fix a restriction in the fuel system. a flow test was suggested and it's a good idea even if it meets specifications it eliminates it as a problem.
On the issue of a rich condition think about what would cause the ECM to supply more fuel than required for the amount of air it thinks is being used.

FUEL PUMP FLOW TEST

1. On diesel engine models, connect a suitable hose from diesel fuel filter feed line into a suitable container.
2. On gasoline fuel injection models, relieve fuel pump pressure, then disconnect fuel feed line and install a suitable hose on line. Place other end of hose into suitable container
3. On diesel engines, turn ignition switch to the Run position.
4. On gasoline engines, apply battery voltage to fuel pump test terminal.
Terminal "G" of the ALDL connector; bottom row first pin on left side
5. On all models, fuel pump should supply 1/2 pint or more within 15 seconds.
I let it flow for 1 minutes and get 2 pints
6. If flow is below minimum, check for fuel restriction. If no restrictions are noted, check pump pressure.

Base91

iTrader: (1)

The fuel pressure should drop a few psi when the throttle is opened. The fact that it went up along with the rich condition suggests the problem may be with the return flow not the incoming flow from the pump. Also, you need to check your injectors. First the resitance. All should be between about 12 - 16 ohms and none too different. If any fall outside replace them all. One or two bad injectors can full the ecu into thinking the mixture is lean so it tries to supply more fuel. This could cause the bogging down. You could check your fuel pressure regulator too with a vacuum pump/gauge. Turn on the ignition but don't start the engine. Pressure should be around what you saw then when you pull some vacuum the pressure should drop a few psi. If it doesn't the fpr may be bad or the return is restricted. follow the lines under the car and look for a crushed or bent pipe. If it looks ok it may need to be disconnected and blown through. Don't forget the basics like looking for vacuum leaks etc. etc.

sofakingdom

iTrader: (1)

Ignore the last post. Every word in it is wrong. EVERY ONE.

Fuel pressure should be at its highest when there is NO vacuum; i.e. when the pedal is on the floor. That's why you check it by disconnecting the vacuum line, which is NO vacuum, which simulates wide-open throttle. Stock, it should be around 43-44 psi at that time. It should be at its LOWEST when the car is idling or cruising down the road at high vacuum. Stock, it should be around 37-38 psi at that time.

What did your fuel pressure gauge show after you changed the pump, and you were driving around with it taped to the windhsield? Did it show 38ish whenever idling and cruising, and go up to near 44 whenever you gave it lots of gas, and STAY up there as long as you were demanding power, REGARDLESS of engine RPM, then go back down to 38ish when you let off the gas? That's what it should do.

Injector resistance should be between 15.5 and 16 ohms per injector.

The "O2 rich" code could be from any of several things. First thing to keep in mind, is that an O2 sensor is just that: an O2 sensor. It senses O2. That means, oxygen in the exhaust stream. It DOES NOT sense "mixture"; it DOES NOT sense "fuel"; it DOES NOT sense "how it runs": it senses OXYGEN. Nothing more, nothing less, nothing else. As such, its output is EASILY misinterpreted. Therefore that code doesn't mean "O2 Rich", like, the ECM actually knows somehow that the mixture is rich; rather, it means that when the ECM attempts to make it lean enough that there should be oxygen in the exh stream, the sensor reports that there still is none. That is a VERY DIFFERENT thing altogether from "rich". You could get an actual "rich" condition, for example, by having your coolant temp sensor unplugged; (although that would set yet another code) the ECM would think that it's -40° outside when it's 80° or whatever, and would add fuel accordingly; the mixture would be burn-your-eyes rich, but the ECM might still well be happy with it, until the engine had run for long enough that the temp should have come up above freezing somewhere and the ECM is smart enough to know that if it has been running for 15 minutes or something and it's still at -40°, there's SOMETHING wrong.

Because the various sensors that the ECM has - O2, TPS, CTS, MAP, MAF, the dist - are ALL IT KNOWS about the outside world. Those are its eyes, ears, fingertips, smell, and ever other sense. It can't know "the so-and-so is broken, change it out"; it can't see that. That's not what "codes" mean. For example, in a car with a MAP, the ECM can see throttle position, engine RPM, and vacuum; if it was to see the conditions of low RPM, high vacuum, and wide-open throttle all at the same time, it would KNOW this combination of inputs is impossible (because its program tells it so), and it would set a code for SOMETHING. Who knows whether it would be the RIGHT thing; most likely, in that case, it would be TPS, since it's the one most likely to fail that could create that physically impossible combination of indications. But YOU, the mechanic, have to be smart enough to interpret the "codes", and find the actual cause, and not just blindly swap out parts thinking that whatever "code" the computer gave you, automatically means "replace the such-and-such".

Typical reasons for why the ECM can't get the mixture lean enough, include a leaky injector; the FPR broken and fuel leaking from it into the manifold via that little vacuum line; and the FP WAY too high, such that it has to reduce the injector duty cycle beyond its normal tolerance to reduce the amount of fuel it feeds.

Other typical causes for that code include a faulty O2 sensor; they're easy to damage in a number of ways, and one of the things they can do when damaged, is to be unable to output the correct signal for a "lean" condition. The ECM is constantly trying to vary the mixture acrss the O2 sensor's "boundary"; it acts like a switch almost, and not a linear indicator, in that only a very tiny amount of oxygen makes it read full-scale "lean", and only a tiny bit less than that makes it read full-scale the other way "rich". At all times except WOT the ECM is varying its fuel curve back and forth across that "boundary", and will set a code if it doesn't see enough "cross counts". Even though you say you've changed it out, I'd suggest trying a new one.

Another thing to watch out for, is when there's a misfiring cylinder (fouled plug, bad plug wire, etc.). Then, the ENTIRE contents of the cyl get dumped out UNBURNED into the exhaust, INCLUDING one whole cyl's worth of .... you guessed it .... OXYGEN. Under that condition, NOTHING the ECM can POSSIBLY do, will EVER get rid of the excess O2 in the exhaust; and it may make the engine run burn-your-eyes rich, and all the while set the "O2 lean" code. While that's probably not the case in your situation, it's an example of how what the "codes" tell you, CANNOT just be taken at face value; a little more thought has to go into them, than that.

JAWZGIRL

ok here it is the psi on car after I changed was 43 idleing and then normal driving then I drove it went up to 50 psi but it still bogs down worse then ever now but psi doesnt go down on bog just when I let off gas back to 43 so I am thinking not the gas

JAWZGIRL

changed the o2 sensor again and the car still bogs down worse then ever now , fuel pump changed pressure idle 43 driving 50psi now when I rev idle bogs down not feeling so well any more about getting to the problem so please help , some one said distributor coil could this be it down to this last idea. helllppp!!!!!!

aljohnsonii

how long did the car sit it could have a rusted tank had a similar problem i ran a fuel system cleaner through it and it knocked the rust off the tank and kept messing up my filter would have correct pressure at idleing but driveing down road with tank sloshing it would wont to die

thegooseman

Im just going to throw this out there.

Ignition control Module.

The first time mine went out, the symptoms I had leading up to it was the car was bogging and loosing power. It would idle just fine but as soon as I got up to speed the problems came back. I thought it was fuel related until one day when my car finially died. The mechanic replace the ign module and problem solved.

Sexonfire14

Plug in a scan tool. OBD1. go under "data stream" and drive your car, at the same time check all the info it gives you. tps should be set at .5 volts. sounds like its not set right. see the throttle position sensor is a demand sensor, it tells the computer what the drives wants to do. its getting a wrong signal and it wont know to add more fuel, the bogging down is the car going lean. and the idle goes up when you let go because ur idle air control valve kicks in.

JAWZGIRL

OK so heres what i did recent went out and cleaned air intake and under egr and replaced the tps again cause thats what I thought to . I drove it after a while same thing then I took out 02 sensor and drove it drove a little better but still died , so I cut the pipe after the cat thinking maybe the muffler bad and it did same thing then I cut the whole cat off cause then I thought that was clogged and nope that wasnt it , noticed a little bit of ark in number 6 but pushed sleeve in more and that went away. I am crying now as this is my baby and I cant figure out . also called a chevy mech. and ran everything by him he also thought cat but like I said that wasnt it. really rough idle dies out when you drive over 30mph sometimes wont start. thinking of blocking egr to see if thats possible it , but its coming down to next new distributer shaft next but trying to save money here not like thats happening also had mech do that fuel thing and it was fine he said

aljohnsonii

yeah youll get good pressure but if the tanks rusted it sits at the bottom and when you drive it kickes up the rust id check the filter again and and if your fuel pumps easy to get to id take a flash light and see what color the bottom is if its clean then see how worn the vats key is it might be loosing resistance on the ohms on the key and if its very worn then your key will jump around in the ignition and your car will think theres no key and loose fuel and die

JAWZGIRL

OK no rust I looked inside the tank when I just changed out the pump and no debri either , also as for the vats the keys I have are new and thats not the problem

JAWZGIRL

this whole problem started when I went to pass someone on a stretch of road punched it and car bogged down then went up and has been getting worse since or should I say right now cant even drive around block without it shuting down

aljohnsonii

check the tank and key had problem like that with first camaro on third now

xch3no2

Don't be upset, this has an answer somewhere.

It might pay to remove the injectors for a visual inspection & flow test.

aljohnsonii

did you replace cylinder to or just key
if you replace both then all i can tell you is to change your computer or ign control modual in the dis. once it gets hot it kill the car and the computer could have a burnt resistor in it that causes it to go in limp mode

xch3no2

Another basic I haven't seen covered in your thread,

Has the timing been checked?

Project 3.4 Camaro

I'm thinking its ICM, or that the o2 sensor and MAP aren't wired right, or are bad(I've heard alot of people getting new sensors that are bad) or the ECM is bad, or vacuum lines, or maybe the TPS needs adjusted....thats my best guess, and just curious, is the car a 305 or a 3.1?
And a vacuum leak if bad enough and depending where it is, can actually prevent the car from holding idle on its own and cause massive power sap....I had a really bad vacuum leak at my intake manifold that was causing me hell...had to tear it down and reseal the whole damn top end...
And don't loose hope, have to just keep plugging away at it, you'll get there eventually, my car has had a good many issues that were hard to overcome...but eventually I did, and now its almost daily driveable, took me over a year to get to this point...problem after problem, just have to take it one at a time, knowing that eventually it will run out of problems if you fix them as they pop up,lol.....

ASE doc

First of al, I do not advocate replacing parts or doing any type of repair without first verifying the failure by performing tests. I did not mean for you to replace your fuel pump, unless it failed one of the prescribed tests. That said.......

Your problem may very well be ignition. Ive seen ignition failures act alot like fuel system failure. The code 45 "exhaust rich" code would fit with that. What Ive seen is a drop in ignition KV severe enough that combustion falls off and the engine sends unburned and half burned fuel past the O2. You feel a drop in power and the O2 sensor sees "rich exhaust", or in some cases, if the fuel is completely unburned, the O2 sensor sees "lean exhaust". O2 sensors do not recognize HC, only the difference between CO and CO2.

The test for this is simple. Use a cheap inline spark tester and a long ignition wire to route one plug wire so that the spark tester is visible while you recreate the failure. Watch for spark to drop off as the engine loses power.

If this happens, proceed with testing your ignition system. perform a KV test to verify the coil's health. Have the ig module tested. Ohm test the pick up coil. Never assume because you have replaced the distributor or any part of it that it's working properly. Parts, especially cheap parts, come bad in the box all the time.

JAWZGIRL

today I replaced the distributor came with new ign mod I set the timing to 10 started then after a little warming up died then I cleared computer again and now doesnt start at all ,pulling hair out now

thegooseman

I dont know if it would cause it to die but I believe the timing is supposed to be set at 6 stock. If im wrong someone will chime in and say otherwise.

Project 3.4 Camaro

just to see what happens...spray some starter fluid into the intake, that will at least rule out fuel or spark...

JAWZGIRL

sorry read many threads and its 10 for timing , thinking its something to do with spark but just havent figured out having it towed to mech. cant take it anymore. I changed everything and nothing worked

sofakingdom

iTrader: (1)

Leave the timing alone. It doesn't just up and change by itself. Even if it did, it won't make the car do what you're saying your car does.

Not the computer, not the O2 sensor, not the vacuum lines, none of that. Vacuum lines for example, could be COMPLETELY MISSING if you were driving with the throttle wide open (foot on the floor), and make basically NO DIFFERENCE. Leaks of that sort have the greatest effect at idle, and have progressively less and less as the vacuum drops. Since your problem doesn't follow that pattern, that's not the cause.

You have a fuel problem of some sort. Still.

What does the fuel pressure gauge do when you drive it down the street taped to your windshield? We still haven't heard about that. Sounds like all you've done is watch it while it was sitting in the driveway and you give it gas. That's NOT ENOUGH. You have to see what it does UNDER LOAD, in NORMAL operation.

Clear your mind altogether. Free yourself from panic and irrationality, and relax. Cease to be a slave to fear and ignorance. Then read my signature and apply it to your situation.

cuisinartvette

How old are the catalytic converters





One thing at a time here you could have multiplle problems. Youll get it sorted out be patient and follow the steps the guys here have posted youll nail it then like the car again. Gets frustrating doesnt it

JAWZGIRL

the cat is a year old but cut that off and that wasnt it as for the the psi I did drive the car with it taped on the shield and it was 43 at idle and 50 driving not sitting in drivway

xch3no2

ok...everybody read the whole thread again, some are asking questions already answered.

Injectors still need checked...see post #15 & 29.

robotic_junky

IMO, borrow a scanner and check the MAP sensor to see if it's working right. If it's not working right, then it could be the sensor, the wiring for the MAP sensor, or both. Also check the vacuum line going to the MAP sensor.

You could also unhook the MAP sensor and drive around a couple blocks and see if you see a difference.

Air_Adam

I have to agree with Sofa... he's on the right track - has been right from the start. Check your fuel pressure when the problem is occuring. You need to be able to catch the issue 'red handed' so to speak.

nomad350Z

I think even the mod needs to read the whole post.

She did check the fuel pressure while driving, it was 50psi. Idle at 43. Thats been stated 4 times now.

Its not a fuel delivery issue, its a fuel proportionality issue.

Like ASE and Sofa Kingdom said, the O2 sensor is sensing oxygen, and adding fuel to compensate. Too much fuel will bog the engine too.....ever try the can of paint and a match trick as a kid? Hold the match just far enough will make a fireball....hold it too close and it goes out.

1. Check all of the injector resistances. As stated previously, should be around 16 ohms. Do this when the engine is cold, and when its warmed up for awhile. I realize it won't run, just let it idle for a while to generate some heat under the hood. The resistances hot will be less than when they are cold, but never less than 14 or so.

2. Compression test each cylinder. You noticed the car bogged after you tried passing someone...you may have cracked a cylinder ring, causing unburnt oxygen to flow past the 02 sensor.

3. Calibrate the TPS sensor.

All of these tests are cheap compared to what you've already done, and will tell all of us indespensible information to get you going. If you don't know how to perform the tests, do a search. If that doesn't help, ask us on here.

JAWZGIRL

Still cant start car to do any test its done I reach my end of the rope

HawkZ28

iTrader: (2)

Are you sure that you're getting spark? I'm thinking since you replaced the dizzy, it ran, and then stopped running, that may be your problem. Double check the grounds INSIDE the dizzy. Try your old ICU as well. Don't give up! You're close!!!!

blacksunshine'91

iTrader: (10)

I'm having the same code, but the exact opposite situation. After warming up (such as a short highway drive) and then idling for a bit at a stop light the car will idle very rough before dying. It'll start back up but as long as I sit at idle it will die again. If I get back on the highway or down the street at a decent speed the check engine light will go off and it will run fine until sit at idle again. Already replaced the O2 sensor which made the situation better, but not gone. I think I'll replace the fuel pump relay to see if that affects it.

ASE doc

I hope you will take a few days to gather yourself and go back to basics. Compression, spark, in reasonably correct time, and fuel are what's needed for an engine to run. Check each of these. If your car doesnt start, it's because one of these isnt happening.

I hate to play devil's advocate. I know how hard youve worked at this. However, good diagnostic technician could figure this problem out fairly quickly and might save you alot more frustration. The hardest part is finding an honest, skilled and knowledgable technician. One clue to finding one is to look for ASE Master Technician L1 Advanced Engine Performance Specialist. This person knows your engine management system better than most anyone. One hour of diag time is generally about $90. Could be a bargain for you at this point.

88blkiroc

Take it to a mechanic already. You spend more time and money throwing parts at the car then just taking it to someone who knows what they are doing and can fix it right without guessing. I know there is pride in fixing your own vehicle but if you are tossing this many parts on and dont know what to check you are screwing yourself over by not letting a professional handle it.

JAWZGIRL

ok I threw it on a flatbed and towed it to the mech. him and another person from chevy are going to figure it out for me and will cost me min. I will get back to you on what he thinks also when I dropped off he got to hear how bad it is and seem like this will be a good challenge to him also, after all I changed all sensors even the map again and throttle checked all volts on it all and they are all right on. so give me a week and I will get back to you all. thanks so much for hanging in with me