[jaybaum96]

Even though the L67 swap is coming, i still want to fix this problem for at least a few months. Ever since i replaced my UIM my car seems to bog/loose acceleration power alot. Before the UIM replacement, it did bog but about 1% of the time i pushed on the gas. Now it seems to be happening about 75% of the time. I know for sure i have no vacuum leaks, no check engine light and no misfiring cylinders. When i had the misfire/uim problem a few months back the pcm was throwing random codes for sensors - 2 of which i replaced (the TPS and IAC). I have brought my car into my auto class at school, we scanned the car - no codes. The voltage coming in and out of all of the sensors is correct. Personally i think its either the upstream o2 sensor, TPS or MAF sensors slowly going... Regardless of whats happening, the pcm is not showing any faults or anything what so ever as a trouble code.

The car bogs down any time it wants when i am accelerating, and i know i have been running slightly rich. Also, when an air/fuel gauge was connected during the bogging time the gauge went back and forth (from lean to rich) at the same "tempo" as the sound of the bogging. And for example with the acceleration, if i go 100% throttle or WOT, it will go, but it will suddenly drop in torque as the engine sounds like its still sucking in air.. The tranny is perfect, it is DEFIANTLY not a tranny problem. Anyone have any ideas what it could be getting caused by?

-sorry about the essay- hahaha

[me6894]

How do you know for sure you don't have a vacuum leak? What are you fuel trims with the car idling? Have you scanned for misfires while this is happening?

[jaybaum96]

and to add to it, my rpms dont drop its just a feeling that the car looses power. Sometimes if i pull over and turn the car off and wait about a minute, turn it back on it wont bog down at all for the period of time during that start cycle. But it would do it next time i start the car which makes me think it is a sensor.

[jaybaum96]

me6894, on 17 March 2010 - 10:10 PM, said:

How do you know for sure you don't have a vacuum leak? What are you fuel trims with the car idling? Have you scanned for misfires while this is happening?

I know for sure it isnt a vacuum leak because it only happens sometimes when the car is driven. Like i just added, if i turn off the car and turn it back on it sometimes it wont happen at all until its shut off and turned back on again. Fuel trims, not sure what they are during idle... And yes i scanned for misfires while it is happening, none occur.

[dykzeulb]

I was going to say misfire, because mine did that, but I would say a leak..

[ChibiBlackSheep]

Could it be a clogged cat?

My car bogged pretty bad when mine was clogged

[jaybaum96]

I know for sure it isnt a vac leak, because when it does happen it only happens when the car is warmed up. Hmmm it could be a clogged cat, but wouldnt that set off a code for the second o2? Also, the fact that the bogging occurs 2/3 times the car is driven makes me think it is an electrical/sensor problem. For example, if im driving and the bogging is occuring, i can pull over and turn off the car. I can then start the car and it wont do bog what so ever. Then next time i start it up and drive it, it will bog.

[jaybaum96]

To test the problem today i drove around for an hour before work and racked up 65 miles. I drove through parkways, stop and go suburb streets and highways. My car did not bog down once... I got back home (turned off the car) ran inside to grab some food, went back outside started it up. It bogged about half the time i hit the gas on the way back to work. And my car was fully warmed up. Any ideas? Im still thinking the front o2 sensor is slowly going. I get payed tomorrow so i'd like to spend my cash on something worth while like fixing this. haha.

[Nick07]

jaybaum96, on 18 March 2010 - 10:17 PM, said:

i'd like to spend my cash on something worth while

Continue dealing with the problem and save your money for the L67 swap. If something breaks or fails in the mean time just fix it if you have to. Problem solved /thread

This post has been edited by Nick07: 18 March 2010 - 11:50 PM

[jaybaum96]

Well id like to fix it, being that it is annoying as f**k and it sometimes occurs in front of cops and such. Im sure thats all cops want to hear is a loud note of exhaust and then an engine going WOT hahaa. I just want it fixed because i dont know how long it will be until i finally swap. Realistically it is the only thing wrong with my car at the moment.. I am really convinced it is the o2 sensor after everything im finding on here and other forums..

[blazerman3]

Read my post for "stalling while hot". It may or may not help but there it is.

[blazerman3]

Is this a MAF problem?

[jaybaum96]

blazerman3, on 19 March 2010 - 11:16 AM, said:

Is this a MAF problem?

thats what im trying to figure out, im thinking o2 sensor because my car doesnt die at all. The idle on my car is fine, runs fine accept for acceleration at times...

[blazerman3]

Had a problem similar to this on a `84 Olds...It was the MAF....ran rich all the time...

[jaybaum96]

blazerman3, on 19 March 2010 - 05:43 PM, said:

Had a problem similar to this on a `84 Olds...It was the MAF....ran rich all the time...

and at times it would bog down during the acceleration?

[blazerman3]

Always would.....fuel mileage went totally bad....

[jaybaum96]

did it ever have times where it wouldnt happen for a period of time?

[nitehawkjcb]

Eh... Bogging under acceleration... Could be a lot of things, including a MAF and/or an O2 sensor that's starting to fail.

This post has been edited by nitehawkjcb: 19 March 2010 - 10:43 PM

[jaybaum96]

Still thinking o2 once again is starting to fail. But I also noticed a change today when i sprayed MAF cleaner on the maf sensor, it fixed the problem for about 20 minutes. So that could quite simply be the problem....

[me6894]

If you think its the MAF unplug it and drive with it. If it runs fine then that was your problem. Without having a scanner to read different parameters while you're driving you're really just guessing.

[jaybaum96]

me6894, on 19 March 2010 - 11:42 PM, said:

If you think its the MAF unplug it and drive with it. If it runs fine then that was your problem. Without having a scanner to read different parameters while you're driving you're really just guessing.

so your saying if i unplug my maf and drive around with no filter, no maf on - my car should ideally run fine? And if it does thats the problem??

[Dbl_D718]

No no, just unplug the electrical connector from the MAF, but leave everything else in place.

[jaybaum96]

haha im clearly not reading right. But if i disconnect the maf, wont it be doing the exact same thing?

[nitehawkjcb]

No. For instance - my car runs fine with the MAF unplugged. Once plugged in, the car chugs and dies.

[me6894]

Like said above, unplug it not disconnect it. Just unplug the electrical connector but don't touch anything else. Leave the maf air tube and air filter connected to the tb.

[jaybaum96]

hmm, ill try this after work tonight.

[jaybaum96]

any ideas on if why it was unplugged it ran fine, and then once it was plugged back in it is idling at 2500 rpms?

[me6894]

jaybaum96, on 14 April 2010 - 04:43 PM, said:

any ideas on if why it was unplugged it ran fine, and then once it was plugged back in it is idling at 2500 rpms?

you need a maf sensor