2002 Trailblazer Bogging Down? [Archive] - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum

: 2002 Trailblazer Bogging Down?


Driver_dav
07-06-2010, 11:37 AM
I have a 2002 chevy trailblazer with a 4.2L and when i start it, it bogs down as i drive i can put the gas to the floor and does nothing it has died a couple times and i have a check engine light io tried scanning a few different times with different scanners from o'reillys and it will not connect to my truck at all or read anything i cant afford to take it in but i am mechanically inclined someone help!! :confused:


UPDATE: i just ran it and turned the ac up all the way and also shut it off and that did nothing heard from some they had that be the problem; with the rough idle i can hear a clunk/clank type of noise coming from the engine now and then mainly when the idle kicks up.

ylab
07-06-2010, 11:49 AM
First we need to fine out what's going on, or what does the PCM think is going on. If the code reader is unable to connect, check the cigarette lighter fuse.....that fuse also supplies power to the OBDII connector. Hopefully its just a blown fuse preventing the scanner from working.

Is the light flashing? - If it is, it indicates a miss on one or more cylinders and you shouldn't really drive it. (With a miss, you'd also idle horribly rough).

The early years have some common issues that can cause those symptoms and we need the info from the PCM to really help.

Driver_dav
07-06-2010, 12:06 PM
First we need to fine out what's going on, or what does the PCM think is going on. If the code reader is unable to connect, check the cigarette lighter fuse.....that fuse also supplies power to the OBDII connector. Hopefully its just a blown fuse preventing the scanner from working.

Is the light flashing? - If it is, it indicates a miss on one or more cylinders and you shouldn't really drive it. (With a miss, you'd also idle horribly rough).

The early years have some common issues that can cause those symptoms and we need the info from the PCM to really help.

the cigarette lighter is fine i have been using it this weekend but i believe my rear hatch one didnt work are those seperate fuses? and the engine light is not flashing.

ylab
07-06-2010, 03:17 PM
Ok, not fuse that feeds the OBDII connector. Any aftermarket electronics connected, that might be affecting the ability to pull the codes? (Some of the remote start kits and such wire to the system to bypass the pass-lock anti-theft device).

Just w/o seeing it or having access to the codes, its a cr@p-shoot. My first thought on it bogging is a clogged converter or exhaust, which should set a low converter efficiency error when it gets that bad. - Has it been low on power before the light and severe bogging?

If you want to try and rule out the converter, you can briefly pull the O2 sensor (one on manifold). Take a spin around the block and see if the engine is more responsive. If the problem is less severe, you most likely have a clogged converter. (Which will eventually set the CEL). I"d personally prefer to get the connector working and read the codes, so we know what we're dealing with.

Driver_dav
07-06-2010, 03:56 PM
Ok, not fuse that feeds the OBDII connector. Any aftermarket electronics connected, that might be affecting the ability to pull the codes? (Some of the remote start kits and such wire to the system to bypass the pass-lock anti-theft device).

Just w/o seeing it or having access to the codes, its a cr@p-shoot. My first thought on it bogging is a clogged converter or exhaust, which should set a low converter efficiency error when it gets that bad. - Has it been low on power before the light and severe bogging?

If you want to try and rule out the converter, you can briefly pull the O2 sensor (one on manifold). Take a spin around the block and see if the engine is more responsive. If the problem is less severe, you most likely have a clogged converter. (Which will eventually set the CEL). I"d personally prefer to get the connector working and read the codes, so we know what we're dealing with.

i found 2 dead fuses one for cig lighter other was a aux power or something replaced and i could read the code was a small evap leak from my gas cap oring bad would it bog down for that code up for a while, i will know if that fixed it on my way home tonight

Driver_dav
07-07-2010, 01:41 PM
So I replaced those fuses and scanned it was just the stupid gas cap (degrading o-ring) and i cleared it so there is now no lights, and this morning it was bogging do again at one point it almost sounded like it was kinda reving but not driving (dont quote me) and also the little orange light for the 4-wheel drive control is not on do not know if that has anything to do with it but mainly its bogging i have put it to the floor and it seems to like die more but when it gets warmed up its fine? im so lost and confused help

Driver_dav
07-21-2010, 04:53 PM
so i am still having issues and really cant figure it out i have no codes but when i go to hit the gas its kinda like it bogs more and if i just hold the gas halfway it will bog then a little while later it all of a suddens kicks up and runs fine? i need help!!!

petevw
07-21-2010, 05:29 PM
Not saying this is the problem, but it's something that MIGHT cause it, and needs to be done periodically anyway.....has the throttle body ever been cleaned?

If not, or you don't know if it's ever been done, go to the auto parts store, get a spray can of throttle body/fuel injector cleaner, and clean it:

http://forums.trailvoy.com/articles.php?do=viewarticle&artid=91

christo829
07-21-2010, 05:35 PM
Might seem simplistic, but have you ever cleaned your throttle body? That's
a cheap and easy item to eliminate. EDIT: Petevw beat me to it..me and my slow
typing!

You might be fighting a PCM learning problem as well, where it has learned
how to run with the leaky gas cap, and now that you've fixed that, it
still has to learn how to run "properly". It takes a few run cycles to
relearn, and if there are other issues, it might take longer.

After the throttle body, plugs and O2 sensor would be something to look
at.

You don't mention how many miles you have on it. Some members clean
their throttle bodies every 30-45K miles. Plugs should last 100K, but
not always. If you don't have AC Delco 41-103's in, that could be a
problem as well, and some change their O2 sensor at the same time
they change plugs.

The catalytic converter *might* be an issue, but that seems to usually
express itself as an overall lack of power, rather than no power just at
takeoff.

Go with the throttle body clean first, and maybe some fuel system
cleaner (either a Seafoam treatment or some Techron in the tank),
and see if it makes any difference. That's the cheapest route at the
moment. If it doesn't make a difference, at least that can be crossed
off the list, and we can try to do some more diagnostics.

Good Luck-

Chris

leatherneck69
07-21-2010, 06:24 PM
I seem to be having a problem very similar to Driver dav's. My 2002 TB started bogging down on me and dying at stop lights last summer. It would only happen when I first started the vehicle after sitting for several hours (mostly overnight). I read on here about cleaning the throttle body and changing the fuel filter. Cleaning the throttle body was very easy and hopefully that'll fix your problem, Driver dav. I did that and everything worked fine until a few weeks ago.

Now my TB bogs down in the morning and right after work, but runs fine after about 5 minutes. My gas mileage sucks (worse than usual anyway) and it's just plain annoying. I cleaned the throttle body again. I have 94k miles on it and I'm planning on changing the plugs this weekend. I'll let you know if it makes a difference. I'm glad you guys mentioned the O2 sensor because that was going to be the next thing I tried. Thanks.

ylab
07-21-2010, 07:32 PM
I was pretty sure you'd find a fuse blown. That's the most common reason for the OBDII connector to not work with a scan tool. And you have no detected problems, other than the gas cap....which doesn't affect driveability.

When cold the engine runs rich to enhance cold operation, problem is that if the throttle body is slow to open, you end up having fuel dumped into the intake without sufficient air. (Too rich is a problem). Besides possibly causing the motor to bog down, due to the excessively rich condition, you also run the chance of harming the converter due to the excess unburned fuel in the exhaust. - Next step like mentioned above is to clean the throttle body (front and back), disconnect the battery to allow it to learn the new TPS sensor response and I would also pull a plug to check for fouling. (If it ran rich long enough, the plugs might be fouled a bit as well....just check 1 or 2 of them).

leatherneck69
07-21-2010, 09:36 PM
ylab - I'm glad you mentioned disconnecting the battery to learn the new TPS sensor response. I didn't do that before which may have been part of my problem. I did it tonight though. I also cleaned the throttle body again and changed my plugs. 2 or 3 of them were still wet. I'm not much of a mechanic, but I know that wet plugs ain't good. Runs like a champ again! Glad you guys are here. Hope your problem is just as simple to fix Driver dav. :thx

Driver_dav
08-04-2010, 01:17 PM
Another Update:

I replaced the fuel filter and also my Fuel Regulator I have had many tell me those to items too; no such luck still bogs so my next attempt will be cleaning the throttle body i will let everyone know thanks so far!!

Driver_dav
08-23-2010, 09:10 AM
so i cleaned my throttle body yesterday it was nice and shiny and also unplugged the battery terminal to reset and still nothing!?!? I need more idea's?:confused:

jcjarhead
08-23-2010, 05:08 PM
Ylab suggested this a while ago? Could it be? The way you describe it; I have very similar effects...and a clogged CAT.

All better now with the Magnaflow!

Driver_dav
08-23-2010, 05:24 PM
Ylab suggested this a while ago? Could it be? The way you describe it; I have very similar effects...and a clogged CAT.

All better now with the Magnaflow!

i never thought the cat cuz all my experience with those is problems when it gets warm, my next might be sparks they looked kinda crudy

CRoberts
08-26-2010, 09:53 PM
I have a similar problem the truck would run like it had reduced power and put the gas petal down and would come out of it and run strong. and some times stall out and die when coming to a stop so today i got feed up with it and took it to chevy the found nothing in the computer so he tested the fuel pressure it was at 20psi waaayyyy under spec so i am going to put in a new pump tomorrow i didnt think it would be the pump because it didnt starve out in high rpms but it must have got just enough flow to do it i would say get your fuel pressure checked its worth a shot. mine has 180xxx miles so its done pretty good i guess

bluedolphin2669
07-23-2011, 03:26 PM
so i am still having issues and really cant figure it out i have no codes but when i go to hit the gas its kinda like it bogs more and if i just hold the gas halfway it will bog then a little while later it all of a suddens kicks up and runs fine? I need help!!!

so i cleaned my throttle body yesterday it was nice and shiny and also unplugged the battery terminal to reset and still nothing!?!? I need more idea's?:confused:

please let me know if you fixed this problem... My 2004 trailblazer is bogging down when i try to push on the pedal and i am at my whits end with it... Thanks

bluedolphin2669
07-23-2011, 03:28 PM
i have a similar problem the truck would run like it had reduced power and put the gas petal down and would come out of it and run strong. And some times stall out and die when coming to a stop so today i got feed up with it and took it to chevy the found nothing in the computer so he tested the fuel pressure it was at 20psi waaayyyy under spec so i am going to put in a new pump tomorrow i didnt think it would be the pump because it didnt starve out in high rpms but it must have got just enough flow to do it i would say get your fuel pressure checked its worth a shot. Mine has 180xxx miles so its done pretty good i guess

my 2004 trailblazer bogs down and just yesterday died at the red light on me but started right back up... Did you fix yours???

Driver_dav
07-24-2011, 01:12 PM
please let me know if you fixed this problem... My 2004 trailblazer is bogging down when i try to push on the pedal and i am at my whits end with it... Thanks

my 2004 trailblazer bogs down and just yesterday died at the red light on me but started right back up... Did you fix yours???

I did not fix my, somehow it fixed itself, it just stopped having problems, very confused? then about one year later around the same time it did it a couple times again now its done.