OK I give up

[graden]

So my car is doing some thing really weird all of a sudden and I cant figure it out.

When you start the car and leave it in park, I runs ok for a few sec, then it starts to surge a bit. There can be a real bad shutter in the engine from time to time allmost like it wants to stall.

Then, when you put the car in drive and accel under a gentil load, it does the same thing. stumbles and acts like theres a dead cyl.
Then resumes back to normal driving again for a few sec, then does it again.

If you stomp on it, you get no stumbles in the engine at all.

After the car warmes up for a bit, both idel and light load drive stumble seem to ease a bit to allmost none at all.

So far I have changed out.
All 3 coil packs,
spark plugs,
Plug wires,
Pcv valve,
Fuel filter,
Cleaned the k&n air filter,
Had a oil flush and change, ( incase of sticky valve )
Changed the TPS ( got a code 22 )
After changing the TPS I still get a code 22 ( :???: )
Cleaned the MAF sensor,
Cut off CAT and straight piped the exhost,
Cleaned the intake,
Put 2 tanks of gas in the car from different locations,
both 91 octane, injector cleaner and gas line antifreeze to displace any water that might have gotin in the system.

After doing this, the problem lightend up a bit, but is still there.

If I changed the TPS and am still getting a low voltage warning ( code 22) what supplys the voltage to the TPS?

I noticed this started happening about the same time it rained real bad here for a few days and I came to my car to find a water puddle on my passenger floor mat but the windows were rolled up.

Did my ECM get wet and is having issues now?
Any thing else I can check or try before I get a new ECM?
Maybe the rain and this problem are just coinceidental?

I was thinking fuel pump, but if it was, wouldint it be a consistant surge and not like how its acting?

[pokesmot]

is this the 3.3 your speaking of? or 3.1?

what kind of spark plugs did you use? ACDelco seem to work best for most people... have personally (and also heard of others) had problems with bosch spark plugs, and wires.

Another thing I would check is your vacuum lines, make sure all the hoses are good.

I have also had the water from the passenger side problem.. its probably a hole rusting through the firewall, your going to have to peel back the carpet and cut out the rubber insulation away form the firewall before you can find / repair the leak properly.

g2g for now, will try and toss some more ideas your way later.

hope this helps,

pokesmot

[graden]

3.3 Ltr
Vac lines are ok. Checked then and they look clean.
The plugs are champion plats.
The wires are just your standerd 8mm high temp.

[SE2000]

Check for air leaks between the TB and the K&N.

[graden]

looks clean. I have a cold air intake on the engine.
theres 2 screw down clamps on ither side and there as tight as they can go

[TA^Guy]

Don't forget about the fuel injectors.
Not sure what a code 22 means but a bad fuel injector can give misfires simular feeling to a bad ignition would.

[graden]

code 22 is low voltage warning to the TPS. I think the reason I have it even after I replaced and cleared the ECM is because I havent ajusted the TPS not relizing that they were ajustable.

Heres some thing that poped in to my head.
Is the O2 sensor dependant on normal oper temps to give a correct reading to the ECM?

Is it possible that the O2 is dying and causing the engine to burn rich when the car starts up but when it gets warm, it give a correct reading causing the problem to ease up?

[graden]

ok ..

I got the code 22 to go away.
lol.. helps to alighn the TPS before you screw it in to place.
:roll2:

Any ways .. again, it has helped the situation making it not
as bad as when the problem apeared but has not made it go away.

It is how ever, a very bad stumble, until the car warms up to proper operating temps, then the problem seems to lighten up to where its drivable.

So I still have to lean towards a sensor dependant on heat or normal operating temps to correct the problem.

Suggestions??

[ho bag]

Blindly throw money at it until its fixed :)

Honestly you need to start swaping sensors for known good sensors, maybe off a buddys car until you hit the bad one. Sounds like its very very lean as it surges up and then dies.

[graden]

ok so, I went down to auto value today to set a scanner
hooked up to see if they could find any thing.

when they hooked it up, they showed me that the
O2 Sensor was jumping constintly.

rich, lean, rich, lean
and fingerd the O2 sensor to be the problem.

so I bought a O2.

put it in ..... and guess what?
It didint correct the issue. Suprized?..... Im not:roll2:

thats just my luck. So .. I GIVE UP.

Im broke.

I guess next payday I will go down to G.M and have them
run a diagnostic.

I just dont know what to do any more. :(

[MichaelS]

I wouldn't be surprised if it was the Coolant Temp. Sensor acting up... Remember that this is essentially your choke. When the car is cold, it's supposed to command a richer mix. As the engine warms up, it slowly leans out, and will rely on the O2 sensor for tweaking.

btw, the O2 sensor swinging like that is perfectly normal, in fact, that is what it's supposed to do.

Regards,

Michael

[graden]

I have rebuilt grand ams from the bottom up. litteraly .
This is all new and uncharted territory for me.

"How sensors are suppost to act 101"

LOL oh well .. live and learn

Im almost tempted to get 1 from the junk yard to see if it is the issue. I think you can get them for around $2

Its just frustrating because the marrage budget is slowly turning in to the car budget. lol .. sorry hunny

So .. you have to know when its time to call it a day and enough is enough.

[Brad97GS]

Originally posted by MichaelS
I wouldn't be surprised if it was the Coolant Temp. Sensor acting up... Remember that this is essentially your choke. When the car is cold, it's supposed to command a richer mix. As the engine warms up, it slowly leans out, and will rely on the O2 sensor for tweaking.

btw, the O2 sensor swinging like that is perfectly normal, in fact, that is what it's supposed to do.

Regards,

Michael

You took the words right out of my mouth, on both the Coolant Temp sensor and the O2 sensor. :)

[goredsox]

clean out the TB and does the little light on the shifter come on??? if the light isnt on and the car is in park it will cause the air/fuel mix to change because the ecu thinks that it is in gear, and cause it to surge upand down, it happens to me all of the time. Usually i will just put it in N and put the e-brake on, since the light works in N there is no bouncing RPMS...

yeah if ya clean out the TB and MAF that should solve the hesitation...

Engine cold ECU runs in open loop, taking no input from the sensors and naturally running rich. Not until the ECT sensor reaches a certain temp will it cause the ECU to run in closed loop, taking input from all of the sensors... Hope this helps i hate to see a fellow 3300 in distress....

[Pack Rat]

Going back to your original post you said this started after a heavy rain and there was water on the passenger side of the floor. You also mentioned checking your ECM but did not say whether you'd checked it yet. That'd be a real good place to go next. They had a problem of water intrusion where the wire harness comes through the bulkhead. Probably going to find some green wire connections at the ECM.

[HeyDace]

Suspect MAF. Common symptoms would be lean/rich running, surging, hesitation and/or lack of power.

Sometimes tapping the sensor with a screw driver handle will make the engine faulter (sure sign its bad).
Sometimes unplugging the MAF, the engine smooths out some (PCM defaults to programmed engine parameters). This is where you need to be able to watch the MAF signal and know the specs

Unfortunately for most people, they are forced to go to their local "Auto Value" and have the "Tech" scan the codes. In cases like this you need to have a professional that can read and interpret live engine data. Not the guy that says "look, the o2 is switching...thats bad." :lol:

[graden]

Ok .. I changed out the ECM and it seemed to
fix the problem.. at least its driveable any ways.

It still does it a bit, but only for a few seconds on start up.