It's like I lost 200hp at WOT only.
10-25-2009, 05:39 PM
#1
12 Second Club
Thread Starter
iTrader: (4)
Join Date: Jun 2009
Location: Canton, Ohio
Posts: 77
Likes: 0
Received 0 Likes
on
0 Posts
It's like I lost 200hp at WOT only. I have a 2000 Trans Am M6.
Only mod is slp lid with descreened maf. It just had an oil change and a fuel cleaning treatment added from Midas.
Only happens when in WOT.
Happens in any gear.
**************
**New symptom**
The car now idles at 3k rpms no matter what I do now... and it still reads no codes.
************************************************** *************
Air filter is new and good all from SLP (just installed lid setup and bellow).
I will be in WOT and the rpms just kind of hover. It does not kick and jerk but it's like it loses 200 hp in a instant but you have the noise. The rpms do not drop but do not climb anymore as I still have the throttle pressed. Any clues? I do need to ceck the spark plugs but I just thought I should put this out there. Like I said other than that this is a stock 99 Trans Am M6 (aside from the SLP lid setup and I have a descreened maf).
When I had the maf off I cleand the metal quite well. I will try and take a plug off and look at it. This happened once at the track and now happens at any time we are in WOT (every single time but not at 1.2 throttle). Could it be the fuel filter? I am kind of stumped on this. Thank you.
Only mod is slp lid with descreened maf. It just had an oil change and a fuel cleaning treatment added from Midas.
Only happens when in WOT.
Happens in any gear.
**************
**New symptom**
The car now idles at 3k rpms no matter what I do now... and it still reads no codes.
************************************************** *************
Air filter is new and good all from SLP (just installed lid setup and bellow).
I will be in WOT and the rpms just kind of hover. It does not kick and jerk but it's like it loses 200 hp in a instant but you have the noise. The rpms do not drop but do not climb anymore as I still have the throttle pressed. Any clues? I do need to ceck the spark plugs but I just thought I should put this out there. Like I said other than that this is a stock 99 Trans Am M6 (aside from the SLP lid setup and I have a descreened maf).
When I had the maf off I cleand the metal quite well. I will try and take a plug off and look at it. This happened once at the track and now happens at any time we are in WOT (every single time but not at 1.2 throttle). Could it be the fuel filter? I am kind of stumped on this. Thank you.
Last edited by ssjTAdriver; 10-28-2009 at 06:43 PM. Reason: New symptom with * sourrounding it*
10-25-2009, 10:55 PM
#4
How did you clean the MAF? IIRC, the MAF is for start-up and warm-up....then its only used when you go WOT. The 02 sensors do everything after your warmed up to operating temp. MAF joins in at WOT though.
You won't necessarily get an SES light for a failing or bad MAF either....I didn't.
Just wondering if you messed up a little air sensor wire in there.
.
You won't necessarily get an SES light for a failing or bad MAF either....I didn't.
Just wondering if you messed up a little air sensor wire in there.
.
10-26-2009, 08:36 AM
#5
How did you clean the MAF? IIRC, the MAF is for start-up and warm-up....then its only used when you go WOT. The 02 sensors do everything after your warmed up to operating temp. MAF joins in at WOT though.
You won't necessarily get an SES light for a failing or bad MAF either....I didn't.
Just wondering if you messed up a little air sensor wire in there.
.
You won't necessarily get an SES light for a failing or bad MAF either....I didn't.
Just wondering if you messed up a little air sensor wire in there.
.
10-26-2009, 09:40 AM
#6
How did you clean the MAF? IIRC, the MAF is for start-up and warm-up....then its only used when you go WOT. The 02 sensors do everything after your warmed up to operating temp. MAF joins in at WOT though.
You won't necessarily get an SES light for a failing or bad MAF either....I didn't.
Just wondering if you messed up a little air sensor wire in there.
.
You won't necessarily get an SES light for a failing or bad MAF either....I didn't.
Just wondering if you messed up a little air sensor wire in there.
.
Have you ever cleaned and re-oiled that fancy air filter? Excess oil can shed off and contaminate the MAF.
10-26-2009, 10:20 AM
#7
12 Second Club
Thread Starter
iTrader: (4)
Join Date: Jun 2009
Location: Canton, Ohio
Posts: 77
Likes: 0
Received 0 Likes
on
0 Posts
The air filter maybe has 50 miles on it. No, I have not cleaned it. I took it to Midas and will check on it because it happened (that day) after we got it back from their fuel system cleaning and oil change. We had synthetic put in. I will check the plugs when I get it back and inspect the wires. When I say I cleaned the maf, I just mean I took a rag (did not touch the wire) and cleaned a bit of the dirt off. There was very little. It has never been taken apart. Thanks guys. I will keep you posted. There is no check engine light on either. I thought last night it could even be an O2 sensor. Thanks!
Trending Topics
10-26-2009, 10:39 AM
#8
12 Second Club
iTrader: (4)
Join Date: Aug 2003
Location: NorCal
Posts: 1,618
Likes: 0
Received 0 Likes
on
0 Posts
I had the same thing happen to me a couple years ago.... it was the knock sensors. The had been submerged in water from when I washed the engine and then rusted to hell causing them to pull timing at WOT.
It was so bad I took a pic of it.
It was so bad I took a pic of it.
10-26-2009, 12:55 PM
#9
The air filter maybe has 50 miles on it. No, I have not cleaned it. I took it to Midas and will check on it because it happened (that day) after we got it back from their fuel system cleaning and oil change. We had synthetic put in. I will check the plugs when I get it back and inspect the wires. When I say I cleaned the maf, I just mean I took a rag (did not touch the wire) and cleaned a bit of the dirt off. There was very little. It has never been taken apart. Thanks guys. I will keep you posted. There is no check engine light on either. I thought last night it could even be an O2 sensor. Thanks!
The small...tiny...sensor wires in there will break if you touch them too hard with a Q-Tip, if that rag touched any of them, they're history.
.
10-27-2009, 07:17 AM
#12
12 Second Club
Thread Starter
iTrader: (4)
Join Date: Jun 2009
Location: Canton, Ohio
Posts: 77
Likes: 0
Received 0 Likes
on
0 Posts
No I never touched the wire. I guess you can say I just cleaned the housing with no solvent. It happens from 1000rpm to 6000rpm if I test it that long. Of course it didn't do it for when Midas checked it out. It only partially sputters now for a brief moment and seems to me like I had some water in my gas maybe. I always put 93 in the car. The clutch is about 1500 miles old (zo6 setup with a new flywheel too). I forgot to mention that... sorry. It was replaced out of necessity as some idiot put the hydraulic line sitting on the exhaust manifold and it cooked.
The trans does need a rebuild and makes noise but this seems like an all of the sudden event. When the clutch pedal is released there is a noise coming from the drivetrain. It almost sounds like a slow moving grinding stone rotating. So now it barely does the "you just lost 200hp" thing and only in a short 1/2 second burst. I will continue to drive it and test it out througout the week and see what happens.
It seems like what Avengeance said below might be more like what I am experiencing. Like I said it barely ever does it now and when it did it was ONLY at wot, was not gear dependent, and happened from idle on. I only cleaned the housing of the mass air flow sensor and NEVER touched wires. It was quite prior to this happening and if I ruined the maf I would have thought it would have happened sooner. Thank you all so very much for your replies.
The trans does need a rebuild and makes noise but this seems like an all of the sudden event. When the clutch pedal is released there is a noise coming from the drivetrain. It almost sounds like a slow moving grinding stone rotating. So now it barely does the "you just lost 200hp" thing and only in a short 1/2 second burst. I will continue to drive it and test it out througout the week and see what happens.
It seems like what Avengeance said below might be more like what I am experiencing. Like I said it barely ever does it now and when it did it was ONLY at wot, was not gear dependent, and happened from idle on. I only cleaned the housing of the mass air flow sensor and NEVER touched wires. It was quite prior to this happening and if I ruined the maf I would have thought it would have happened sooner. Thank you all so very much for your replies.
10-27-2009, 08:14 AM
#13
sounds ironic that midas touched your car and now it runs like ****.....im kind of curious what they put in your gas tank, maybe your pcm is pulling timing because it hates the fuel....if you want to clean your engine in and out, do it yourself...just my 2 cents tho.
10-27-2009, 08:43 AM
#14
12 Second Club
Thread Starter
iTrader: (4)
Join Date: Jun 2009
Location: Canton, Ohio
Posts: 77
Likes: 0
Received 0 Likes
on
0 Posts
It is not my car. It was my gf's decision.
Symptoms changed now. Now it is idling high at 3000 rpms and I don't have to put my foot on the accelerator to move. I took it home and am now just pondering. I will take a spark plug out tonight but I have to get back to work. This car is really pissing me off. I had this problem in my 88 mustang a long time ago and can't for the life of me remember what it was. It was 11 years ago so my memory is busted. Could it be throttle position sensor? The throttle cable looks fine and so does the spring. O2 sensor? Knock sensor... probably not. It is NOT reading a code either. Thanks guys.
Symptoms changed now. Now it is idling high at 3000 rpms and I don't have to put my foot on the accelerator to move. I took it home and am now just pondering. I will take a spark plug out tonight but I have to get back to work. This car is really pissing me off. I had this problem in my 88 mustang a long time ago and can't for the life of me remember what it was. It was 11 years ago so my memory is busted. Could it be throttle position sensor? The throttle cable looks fine and so does the spring. O2 sensor? Knock sensor... probably not. It is NOT reading a code either. Thanks guys.
10-28-2009, 04:55 PM
#16
12 Second Club
Thread Starter
iTrader: (4)
Join Date: Jun 2009
Location: Canton, Ohio
Posts: 77
Likes: 0
Received 0 Likes
on
0 Posts
I think it might be knock sensor related for the first symptom but now I have the high idling crap... I'm stumped. I really need to check the plugs but I doubt it's a plug issue.
10-28-2009, 05:03 PM
#17
TECH Resident
iTrader: (66)
Join Date: Oct 2008
Location: NC
Posts: 793
Likes: 0
Received 0 Likes
on
0 Posts
I car hesitates, but doesn't just not go anymore like yours. In mine you can hit it and it hesitates for like 1 second then goes and somebody told me to first change out plugs and wires.
10-29-2009, 10:37 PM
#19
Launching!
Join Date: Sep 2009
Posts: 236
Likes: 0
Received 0 Likes
on
0 Posts
I know the answer. . . It makes perfect sense... To run a fuel injection cleaning, you must disconnect the fuel pump and unhook the fuel pressure regulator vaccum line! See if the vaccum line is off the regulator, there may be a bolt shoved in it, or if you are lucky a screwdriver.. It makes perfect damn sense! If this solves your problem, I am a genius. if not, it was a damn good guess.
10-30-2009, 03:34 AM
#20
TECH Regular
Man I wish people would stop pulling screens off the MAF.
MAF problem explains all your problems. MAF is used to fuel the car on start-up cold temps up to operating temps, AND is used at anything over 4000 RPM and WOT. That would explain your high idle and crappy accel at WOT. In my opinion (I'm not getting in a pissing match about this either) when you took off the screen you introduced problems with how the MAF is reading airflow. It's meant to evenly distribute air over the sensor wires, think of the screen on your sink faucets. Take them off and sometimes you introduced un-metered or turbulent air into your engine causing high idle and bad fueling.
Quick and easy check is to unplug your MAF and see how it runs. It will force it to only look at your O2 sensors and may fix your problem. If not then you can cross the MAF off your list and move on to something else.
It may idle crappy at first but should even out and be smooth by operating temps, and if the car is mostly stock you can try a WOT burst for a few seconds to see if it's cured.
If it's the MAF you'll have to replace it and leave the screen in it. I'm sure taking out the spare tire will give you more gains then removing the screen and it won't hurt anything at all.
MAF problem explains all your problems. MAF is used to fuel the car on start-up cold temps up to operating temps, AND is used at anything over 4000 RPM and WOT. That would explain your high idle and crappy accel at WOT. In my opinion (I'm not getting in a pissing match about this either) when you took off the screen you introduced problems with how the MAF is reading airflow. It's meant to evenly distribute air over the sensor wires, think of the screen on your sink faucets. Take them off and sometimes you introduced un-metered or turbulent air into your engine causing high idle and bad fueling.
Quick and easy check is to unplug your MAF and see how it runs. It will force it to only look at your O2 sensors and may fix your problem. If not then you can cross the MAF off your list and move on to something else.
It may idle crappy at first but should even out and be smooth by operating temps, and if the car is mostly stock you can try a WOT burst for a few seconds to see if it's cured.
If it's the MAF you'll have to replace it and leave the screen in it. I'm sure taking out the spare tire will give you more gains then removing the screen and it won't hurt anything at all.