RebelGQ

Recently, my camaro has been experiencing knocking on idle. I was driving my car at work, then the damn thing just turned off when i came to a complete stop and it feel below idle rev (7.5 rpm)...
I cleaned the full throtle body and noticed dat my IAC sensor, which goes atop of the throttle positiong sensor, anyways, that IAC sensor was bought brand new about a month ago, then carbon just simply took over. Also, i cleaned the full throttle body about a month ago. ANyways, does this mean I have to changed m o2 sensor, eventhough black carbon still exists?
AND FROM what my mechanic told me, my camaro has a short, i just do not know where that short is coming from. Here is the question, does my o2 control my idling rpm, or does the short contribute to the mechanics of my engine because i tried everything in the book and the damn motor still knocks!!!

drdave88

iTrader: (3)

what kind of a knock is this? would it be an exhaust leak by chance? and what kind of a short is this mechanic talking about?

RebelGQ

he installed my ecm, but he noticed a voltage drop, i kinda pointed that out on some other forum... My knock is wierd because im at a complete stop and my motor will not stay at constant idle, just revs on its own, do u think the short has anything to do with this abnormality?

drdave88

iTrader: (3)

so the short is in the ecm? the o2 sensor wont really affect idle, not what youre describing anyway. are there any codes?

RebelGQ

just 45... i even checked for vacuum leaks, found nothing

drdave88

iTrader: (3)

what is the short he was talking about though?

RebelGQ

well, when he installed my ecm, he used a volt meter, then told me dat my camaro is having some sort of low voltage, and its noticeable... sometimes my volt meter will mark between 8 to 13, then 13 to 18, it just jumps around

drdave88

iTrader: (3)

but where did he use the volt meter? on the alternator? on the ecm? at the battery? talk to the mechanic and get all the details you can.

RBob

iTrader: (1)

As the ECM was just installed it needs to be put through an idle learn routine. Search for 'idle learn' and my username. This needs to be done with the 3.1l any time the ECM looses power.

As far as the voltage jumping around, that will cause all sorts of problems. Check the battery cables and the fusible links off the starter. It may also be that the alternator is bad.

RBob.

RebelGQ

I wonder if code 45 is giving me problems, then again, who knows...

BitchinRS

The code 45 may just be symptom of the voltage drop / idle up and down, needing to have the idle learn done. Fix these issues first then see if it keeps setting the code 45.

If I am not mistaken code 45 is O2 sensor rich. This can happen with the above issues. It normally gets set on my 3.1L just as the engines dies if I am experiancing the above problems.

If you keep running it like this you will eventually need to replace the O2 sensor, and posiably the cat. converter. The cat. converter does not like running rich for extend periods of times, and will eventualy being to melt the inards.

All of these issues can be conected to needing to have the idle learn done. Voltage will drop as the RPM's get to low. The ECm not knowing ware the IAC valve is located can cause the engine to die. To much fuel and IAC valve closed to far will cause a rich situation. Thay are all inter-related.

RebelGQ

I should attempt the Idle Learn then, but how do i know if i damaged the cat converter?

2_point8_boy

You don't until the next time you're up for smog. Usually it'll be ok, so I wouldn't stress too much about it. Unless you are running seriously rich, or have a bad miss, then you should be ok. A little coating of carbon, but it'll burn off.

As for the voltage thing, run the engine and put a voltmeter across the battery, you should see about 14.2 V. If you want to check the ECM ground yourself, you have to find the ground for the ECM and place the red lead on the ground, and the black lead on the B- post. You should see less than 0.05V on the meter. if you see anymore, then you're in trouble and need to fix the ground.

You can also check the Hot side the same way, find the wire that feeds power to the ECM, red lead at the ECM and the black lead at the computer ground, you should see System voltage there (14.2V).

If both of these check out OK, then I wouldn't worry about a voltage problem at the ecm because you have a good power source to the ECM and a good ground from it.

My advice to you is the do the re-learn procedure and see where you're at, then if you want, try to figure out the electrical problem.

KED85

Bad Alternator.
It's worn down
Loose cables or dirty connections
And out by you, you hae loose poor connections for the cables.
Solution
Start replacing lots of major cables or wiring connections.
And if you had added stereos & such, you then found the bad connections (being that power was branched from under hood).
I would go to the wrecking yards & start looking at shells of cars for guidence as to what's worn down, connection wise.
The power jump comes from the alternator either recharging something or as the source/cause of the power surge.
I had a "new rebuilt" alternator fail me (at cost of $115).
It took me SIX icms until I figured out cause of problem.
These MPFI system & F bBody cars require 100% proper voltage to run proper and trouble free.
Code is from teh poor running engine passing the problem to tht sensor.
Once major problems solved, bet you'll have a great ride.
And I'd also suspect the coil, too.
IF original, it can also cause these types of problems.

RebelGQ

the other day i was driving my camaro under this blastid heat, i turned my car into the driveway all the way, then my car just shut off...
today, i had the starter and alternator exchanged, but i should look into the coil...

KED85

I'll bet your starter is fine.
Usually it's' wiring going to starter that fails.
My Old Chvey still has the 1974 original starter on it with new solinoid.
My 1985 rides still are original GM issued starters, too.
Coil, do a simple clip into harness test & go for rides. NOT SECURLY MOUNTING THE COIL IN THE BRACKET. Tape it to fender or something like that.
Cause IF ya still got problems, then ya can return coil easier and save $30-ish

RebelGQ

is the coil underneath the distributor???'
and if so, how can i determine whether my coil is going bad???

KED85

Engine
Under hood
passenger side
Right above exhaust manifold
How can ya tell it's going bad
Well
ya kinda guess because if the engine is exhibiting certain "new tricks" stalling & such & then it dies & no restarts, majority of time it the coil that is cooked & fried.
Why is it fried?
Look at location!
The exhaust heat cooks it.
AND it's nearly 20 years old now.
AND once replaced lots of problem CAN disappear, too.
AND ya can gain more "power" (not much but ya feel it) and better gas milage, too. AND BEST IS the smoother idle....
It is a very good thing to replace the coil.

RebelGQ

i had an 85 camaro V6 before, i knew where the coil for that one, but for the 3.1L, dunno. What tools do I need to do this coil job?

RebelGQ

And what is the name of the coil, so I can pick up one from the auto parts store

KED85

I use Accel stuff
I paid $35 at Kragen

RebelGQ

is it called the ignition coil, and is it hard to remove, or would I require specials tools?

KED85

Your concerns well founded.
Ignition Coil
I mounted mine on the firewall overhang passenger side. Then I took wires off old coil, attached to new.
I left old coil in place, as it was dead.
Give this idea a try to "test" if your original coil is weak.
And this way, there is no need to remove anythign, ya just adding & clip/click wiring.
This is easier mounting a new coil than removing the old coil any day!

RebelGQ

is dat coil where u mounted urs by the map sensor?
its kinda hard to see the image u displayed.
Nice wiring

KED85

Yellow Item back firewall passenger side hanging upside down!
Follow the wiring!
Coils can be mounted most anywhere
AS LONG AS
the factory wiring can reach it!

RebelGQ

Can u display a bigger image where the coil is originally mounted, hopefully it'll give me an ideal where tyo mount mines...

KED85

Com'n read my previous posted answer.
Follow that advice & then go to your car!
Honest you'll find it
It is exactly where I stated it to be.
Over exhaust manifold, passenger side of engine.
Follow YOUR COIL wire from distributor to that coil & there it is (I could have said follow the yellow brick road, but...)
Sorry
Serious, take a look under you hood & follow your plug wires.
One plug wire off your distb. does NOT go to an engine spark plug. That's YOUR current location of YOUR coil.
Keep at it, you'll learn!
Hope and this answer should help ya.
It's a black square cube about size of your fist. Passenger side of engine.

RebelGQ

im used to the 85 v6 I had before, im new to the 3.1L, sorry to ask something dumb

BitchinRS

3.1 is just about the same as the 2.8. Just stroked to 3.1

KED85

So ya know your question is nothing short of challenging.
Especially for yourself.
My answers for your help.
Let us know when ya find it. You will.
Or more simple way.
Go to parts store and ask then for a coil for your ride and then find it under your car hood.
I got my Accel coil at Autozone for $35 & a few days waiting.

86BLUEBIRD

just look at the top of ur distibutor and find the plug wire that is plugged into the middle of the cap and follow it to the coil.

KED85

Found it yet?
PS I'm not driving from the San Fernando Valley to help ya locate it, it's hot enough!
Let us know when ya find it & you will.

RebelGQ

I live in the pomona area, well sometimes i go to los angeles... i will look into the problem tomorrow, i took my cutlass for now... thanks for looking out

RebelGQ

nevermind, disregard the reply... i have to order dat accel ignition coil through kragen

RebelGQ

Bad news, i did install a new ignition coil, but not an Accel Coil... MY camaro did managed to get a little hp, but the idle is still not smooth... Im gonna just take my camaro to the electrician, and figure out where my short is coming from

KED85

Hey ya got this far
ONE MORE SIMPLE STEP TO DO
Before ya take it someone
Later on today at night time, start engine pen hood IF ya see any electrical tracings on wires, you do have a ture problem. Then the next step is to find the source of that electrical power leakage.
Many problems are simple to find if ya see/look for obvious clues.
Burnt plug wires is number one cause of electrical bad news.
Next is poor wiring connections.
Give this "mission" a try before ya take it away. You may find the real cause of your problems this way.....

BitchinRS

Also make sure you battery cables are nice an firm. I just ran into this. Car would run rough and some times wouldn't. Turned out that the + cable could be turned by hand. After tightening the cable my problems went a way.

RebelGQ

I made sure the cables were not lose. I made sure they were snug tight and the cables did not turn by hand... But my problems still did not go away

KED85

Open hood at night with car running & check & see if any cross wiring problems!
Make sure not in area of light for this test!

RebelGQ

I think i might have a clue where my short might be coming from... I think its the ignition coil to the distributor... Im gonna need a wiring diagram and see if im correct... its the only wiring dat has been worked on since i can tell by the wiring

KED85

Do the same test mentioned to see if any clues at where you suspect.

RebelGQ

I took my camaro to an electrician today, well actually an auto electric repair place. they did not find anything wrong with my car, they told me my car runs fine, except its running on rich... Im going to change the o2 sensor tomorrow and probably put a fuel filter... And plus dat wacky voltage is still in effect

RebelGQ

Why does my camaro still spity out code 45 when I replaced the o2... i even cleaned the full throttle body... Can it be possible that the carbon deposits can still exist in my motor and give my ecm bad problems?

86BLUEBIRD

well there has to be a reason that there is a lot of unburned fuel that the o2 sensor is reading. replacing the sensor wont necessarily solve the problem.

KED85

Try a TUNE UP!
Really that'll help ya!

2_point8_boy

Ok, the problem is that you have a lack of oxygen in the stream, you are running rich for some reason and the O2 sensor isn't seeing any O2 left over. There are a lot of things that could cause this, for example:

Stuck Open Cold Start Valve
Bad MAF/MAP
Bad ECT
Stuck Open Injector
Bad FPR
Bad IAT
And a whole slew of other things.

Rich can be only 1 thing...too much fuel, however lean is harder because there are other things like intake leaks and exhaust leaks that can cause that problem. One of the sensors upstream of the O2 is toast, or maybe an injector, but either way, there's too much fuel in there

RebelGQ

I already tried what you guys mentioned, I replaced not too long ago the MAF sensor, the fuel injectors seem fine, the 02 sensor was just replaced yesterday, i recleaned the full throttle body, also the IAC sensor, (sensor which goes atop of the throttle position sensor). What else, I cant think of anything, I think the spark plugs might be covered with black carbon, but i did all this change abbout 3 months ago...

RebelGQ

Try thread, some guy told me that i found a loose vacuum hose, but I dont know where it goes, they call it the ball of power, located underneath the battery (driver side)

https://www.thirdgen.org/techbb2/sho...hreadid=316236

2_point8_boy

Any kind of vacuum leak would cause a lean condition, and a small one would be easialy corrected for by the computer.

The only way to tell if you have a stuck injector is to hook up a pressure guage, run the engine, then shut it off. Leave the guage hooked up, and if everything is ok, then the pressure should hold overnight.

Trust me, if you had tested everything already, the problem would be gone. I don't always trust that a new part is good. i work at a shop and get paid by comission, so if it takes me longer than it needs to on a job, I lose money. The other day I had to replace an alternator on a 3800 series engine, so it took me 15 minutes, BUT the new alternator that they sent me was crap, so i had to do the job AGAIN. O2 sensors, especially cheaper ones, are known for being crap right out of the box. That's the irst thing they teach you when you're training to be a mechanic, diagnose first, change the part, then verifiy that the fix actually worked. Never assume that a new part is automaticaly good.

RebelGQ

dats the only loose vacuum hose i found, but i cannot locate where the fitting is at, i mean the wierd ball dat is