Hesitation, and stalling 2002 LS

When I start driving, my trailblazer hesitates and the RPM's won't go over 3500 even when i have the pedal floored. Sometimes, while sitting at a stop light, the engine will stall. The truck also sounds like a train locomotive when I begin driving in the morning. Any ideas? The noise problem I beleive is unrelated to the hesitation problem. I am already on my second engine due to the piston sleeve problem.

When I start driving, my trailblazer hesitates and the RPM's won't go over 3500 even when i have the pedal floored. Sometimes, while sitting at a stop light, the engine will stall. The truck also sounds like a train locomotive when I begin driving in the morning. Any ideas? The noise problem I beleive is unrelated to the hesitation problem. I am already on my second engine due to the piston sleeve problem.
Welcome to AF. The fan clutch is probably the roar which can also reduce power, get it replaced if the condition is always there, there is an updated unit, pn#15293048. Of course have this checked out first.

Is your SES light lit? Not being able to free-rev might be an indication of a failed catalytic converter. Would not be the first 2002 I've seen reported with a bad cat.

G/luck
Joel

I do not have any trouble lights. I tried spraying some throttle body cleaner into the throttle body but it is still doing it. Any other ideas? I read the post above this one and the person reported a sensor as the possible problem....would that be a possibility for the 2002? Thanks!!!!!!!!!!!!

I do not have any trouble lights. I tried spraying some throttle body cleaner into the throttle body but it is still doing it. Any other ideas? I read the post above this one and the person reported a sensor as the possible problem....would that be a possibility for the 2002? Thanks!!!!!!!!!!!!
Check fuel pressure, how old is the filter is it a misfire or just no power?

I cleaned the throttle body again and took out the air filter. The air filter was filthy, so I replaced it. so far so good. it seems to be running much better.

Thanks Guys!!!

Max, you mentioned the fan clutch as a source of the other problem. Is that difficult to change and is there any special tools required?

Well fellas, back to square one. Hesitation and stalling are back. Any other ideas besides the throttle body cleaning and air filter?

Is the fuel filter a potential candidate and is it difficult to replace. Went to 3 auto stores and no one seems to have it.

It's extremely odd you are getting such drastic operating concerns and no SES light.:uhoh: Have you scanned for codes? My personal experience with clogged fuel filters is the vehicle will start and idle fine, but bog down and stall under load. There's just so many things your issue *could* be caused by that you could go broke thowing parts at it. Driving with some type of code/data scanner plugged into the OBDII is needed IMO.

Joel

It seems to do exactly that, bog down or stall when i am stepping on the gas and putting it under load. It starts right up fine, and idles fine. It also seems to stop having the problem once the vehichle is driving for a few minutes. Is there any special tricks or concerns when changing the fuel filter. I ordered one and it should be in today. This is my last hope before it goes into the dealer :-(

You could pull the fuel pump fuse and crank over the engine to depressurize the fuel system. There is a test port shaeder valve somewhere in the engine compartment that you can push to relieve fuel line press as well. If this doesn't turn out to be the fuel filter, it could be a failing fuel pump or bad fuel pressure regulator. GM fuel pumps don't typically last too long.:banghead:

Joel

thanks again, i'll try it tomorrow and i'll let you know how it turns out.

well i replaced the fuel filter and I am still getting the same problem. I guess it is time to bring it to a real mechanic. Thanks for all the help. If there any other simple things that you can think of that I can try, please let me know. The truck will otherwise go in on Monday.