2000 Bonnie SE stalling issues

[MKMike]

If Andrew doesn't have any good MAFs, a local junkyard may.
If new is needed, Hitachi is the original equipment one to get http://www.rockauto.com/en/moreinfo.php ... 72&jsn=424
The ACDelco OE is the same but priced higher.

[harofreak00]

I did PM him.

[Bad67bird]

I did PM him.

im sorry i did not get back sooner, had a surprise inventory thrown my way ,so no work could be done.

so i decided to use a maf of a running car, the wife grand prix and still no change.

but it get interesting, i cleaned out the iac even thought the scanner said working
fine and there was a slight difference.Now the cut out seems to be anywhere from
1000 rpm to as high as 2500, which causes the car to buck,however it never dies
all the way.When it bucks the tach drops then it can be normal again,completely
random.My security light has been on since ive owned the car (nearly a year) but
its been going off on its own,more and more.Today i hit a bump and the Trac off,
abs lights came on.Could i have a short in the dash or ignition switch?

[MKMike]

so i decided to use a maf of a running car, the wife grand prix and still no change.

If that's the 2004 GP, then it's a different MAF sensor.
If the symptoms are worse with the GP MAF, I wouldn't be surprised.
You tried 3 brand new MAF sensors and they all did this same thing of cutting out at the same RPMs?
If yes, then the MAF seems less likely to be "it".
Ditto for the throttle position sensor.

Since both cars use identical coils and ICMs, I'd swap over the entire coil and ICM set.

If that fails to correct it, then it should be the CPS.

quote="Bad67bird"]
Today i hit a bump and the Trac off,
abs lights came on.Could i have a short in the dash or ignition switch? [/quote]
Doubt it and think this is a separate issue.
Most often this is a bad speed sensor in one of the wheels.
Look at the Common Problems sticky for more details on that.

[Bad67bird]

mike=
If that's the 2004 GP, then it's a different MAF sensor.
If the symptoms are worse with the GP MAF, I wouldn't be surprised.

that makes since,can look similar but not same internal

mike=
You tried 3 brand new MAF sensors and they all did this same thing of cutting out at the same RPMs?
If yes, then the MAF seems less likely to be "it".
Ditto for the throttle position sensor.
yes

mike=Since both cars use identical coils and ICMs, I'd swap over the entire coil and ICM set.
new coils and new module

mike=If that fails to correct it, then it should be the CPS.
new crank and cam sensor
mike=
Today i hit a bump and the Trac off,
abs lights came on.Could i have a short in the dash or ignition switch?

Doubt it and think this is a separate issue.
Most often this is a bad speed sensor in one of the wheels.
Look at the Common Problems sticky for more details on that.

yes i have a bad left wheel sensor according the scanner now

i was test driving the other day (wednesday) and i hit a large pot hole (ya tax dollars
at work) and the entire dash lite up as if the car shut off,however it still accelerated
and the lites went off one by one.

i did replace the ignition switch after that(yes andrew i know you sell them,but the tranny in the
grand prix went out and i cant have both cars down) , it seemed that mine was very loose.

the problem is still there and completely random (ie outside temp,engine temp,idling or on road
driving) but the range is now between idle (700rpm)and hard acceleration (3500rpm) but only
in gear not park or neutral(yes it has a new delco fuel pump as well).could it be i need an new
sensor/module harness?i did clean the ground bus splicer under the module. can a bad ac compressor
cause this? in my sunfire i had bare wire showing and when they touched it cut out the car. the
wires are good,the compressorwas changed last july,but it knocks a little now so could it be a short
in the clutch coil?

just reaching for straws here now by the way on the scanner all system show in good
working order and i ran voltage test again :
charging system voltage PID14.40v
battery monitor votltage PID13.08v

[MKMike]

Not sure if a bad compressor could cause that.
Carefully look at all battery cables.
Check for excessive ac voltage coming from the alternator--just to be sure that's not the issue.
Clean up all grounds and especially check the connections at the ECM.
You could try wiggling connectors and wires to see if you can duplicate it.

Harofreak00 probably has the right gauge set.

[Bad67bird]

grabbed every wire under the hood while it was running and cannot duplicate any of
the issues........the cut out problem only happens in gear........ill check the battery
cables again tomorrow.......ill load test the battery again with the car unhooked as
well just to see what we see......thanx again MKMike

[Bad67bird]

Ok next step is a factory Maf, I'm harness and another computer from Andrew..........we will we what happens

[Bad67bird]

Got the MAF installed, changed out the ecm and now I'm doing the theft relearn proceedure.........did I forget anything to this ro is it truly plug n play basically?

[Bad67bird]

Ok everything is in, programmed and no codes.........even put a new battery in since the other was 4yrs old and leaking.The symptom now is that it hiccups randomly on acceleration, I've changed everything!is it possible that there is some kind of internal vacuum leak?I've sprayed carb cleaner everywhere and no
Changes . I'm really at a loss here

[Bad67bird]

Here is an off the wall question? Could the ttc be sticking?

[harofreak00]

If the TCC sticking is bad enough it will throw a code. I've driven one with a sticking TCC, there was no ignoring it. It stalled the car when coming to a stop and would shift horribly.

[Bad67bird]

Ok I was reach in for straw lol guess I'll try the egr or uim

[MKMike]

Have you ever tested for excessive backpressure?
Either use an exhaust backpressure gauge or a vacuum gauge.
Hooking up a vacuum gauge, hold the rpms at 2000-2500 for 20-30 seconds and observe the vacuum reading.
It should remain steady.
If it creeps downward, your backpressure is excessive and is choking out the engine.
Typically, the converter has become blocked, though the blockage can be elsewhere in the exhaust.
If the catalyst has broken up into pieces, you could get an intermittent blockage.
Banging on the converter and listening for rattling should clue you in if that's the issue.

You might also consider checking STFT and LTFT at idle and again, while holding rpms to 2k-2500 for 20-30 seconds
Post the readings to the forum and we'll let you know if anything is off.

[Bad67bird]

Have you ever tested for excessive backpressure?
Either use an exhaust backpressure gauge or a vacuum gauge.
Hooking up a vacuum gauge, hold the rpms at 2000-2500 for 20-30 seconds and observe the vacuum reading.
It should remain steady.
If it creeps downward, your backpressure is excessive and is choking out the engine.
Typically, the converter has become blocked, though the blockage can be elsewhere in the exhaust.
If the catalyst has broken up into pieces, you could get an intermittent blockage.
Banging on the converter and listening for rattling should clue you in if that's the issue.

You might also consider checking STFT and LTFT at idle and again, while holding rpms to 2k-2500 for 20-30 seconds
Post the readings to the forum and we'll let you know if anything is off.

No I haven't Mike , but I think it's a place to look.........tried two other scanners and still nothing showing up.........now I
do have a couple of secondary air pump codes but I was told that would go away after a drive cycle since I changed the ecm.
Should I take it to the dealer to have it reset?
What is stft and ltft?

What about doing a CASE relearn?

[MKMike]

If it was Andrew who told you the secondary air codes will go away after a few drive cycles, you can be sure it's true.
STFT and LTFT are the short term fuel trim and long term fuel trim numbers.
They can give insight as to what's going awry.
A CASE relearn certainly couldn't hurt.

[Bad67bird]

If it was Andrew who told you the secondary air codes will go away after a few drive cycles, you can be sure it's true.
STFT and LTFT are the short term fuel trim and long term fuel trim numbers.
They can give insight as to what's going awry.
A CASE relearn certainly couldn't hurt.

Andrew never mentioned it, read it in an article however.....Andrew what do you say? Should I be getting these secondary
Air pump codes when my Bonnie doesn't have one?

Aahhhh ok then I'll try to get those numbers , lol I was racking my brain trying to figure out what they meant

And. I've. Read a lot over the last couple of days and it mentions doing a CASE relearn when ever the com,harmonic balancer
Or crank sensor have been changed.

[MKMike]

The service manual does mention sluggish or contaminated oxygen sensors as a possible cause.
The Upstream sensor (Bank 1 Sensor 1, IIRC)should be rapidly cycling from rich to lean.
The Downstream (Bank 1 Sensor 2) sensor should be a rather steady reading.

To check STFT and LTFT take readings at idle and again, while holding rpms to 2k-2500 for 20-30 seconds.

It would be nice if the issue resolved with a CASE relearn.

[Bad67bird]

Ok case relearn was done by the dealer
And it took away the check engine light
And the secondary air pump ..... however it still hiccups


Will be looking into your stuff Mike

[MKMike]

Bummer.
Well, happy Easter or Passover--or simply have a happy weekend!