General Maintenance & Repairs Leaks | Squeaks | Clunks | Rattles | Grinds

4.3 liter vortec hesitation problems

Thread Tools
 
Search this Thread
 
Old 09-13-2005, 05:57 AM
  #1  
TECH Fanatic
Thread Starter
iTrader: (13)
 
redbandit98's Avatar
 
Join Date: Feb 2004
Location: Ft.Smith AR
Posts: 1,164
Likes: 0
Received 1 Like on 1 Post
Default non-ls1 4.3 liter vortec problems

well i know this is a common engine so i thought id ask..i have a 2000 s10blazer for a daily driver. I just bought it about a month ago.

Ive noticed the problem a few days after i bought it, i thought it was just the fuel filter,,thats exaclty what it acts like but i checked it and its fine. It seems to do it worse when its cold..it hesitates really bad.

you dont really notice it unless your getting it on it pretty decent. if your just putting around like i noramlly do its not really noticeable. Its like you can hammer it and it will try to pull then it will feel like it almost gives up then it will start pulling again.

best way to describe it is like teh tq converter is slippiing or something. I am getting no codes and it doesnt seem to be missing. its like a mechanical probelm holding it back..i guess it could be the tranny but i was thinking the cat. it gets pretty crappy gas mileage.. i know they dont get the best but it should get better than it does (about 13 in the city) i think theyre supposed to get about 16 or 17. its either that or the tranny (i think).

i dont know if the plugs and wires have ever been replaced since i just took ownership of it.. its in realy good shape and only has 48k on it. I wouldnt think if it was the plugs and wires it would do it worse when its cold.. i dont know. guess ill start with the cat and then try the tranny.

any suggestions?

matt

Last edited by ACW; 09-14-2005 at 11:15 PM. Reason: paragraph breaks
Old 09-14-2005, 11:26 PM
  #2  
ACW
TECH Veteran
 
ACW's Avatar
 
Join Date: Dec 2004
Location: Beaumont, TX
Posts: 4,012
Likes: 0
Received 1 Like on 1 Post
Default

Here's some stuff to check. The catalytic converter is a possible cause (part of the 'restricted exhaust' item)

"2000 Chevrolet Blazer - 2WD - 4.3L

Hesitation, Sag, Stumble

DEFINITION: The vehicle has a momentary lack of response when depressing the accelerator. The condition can occur at any vehicle speed. The condition is usually most severe when trying to make the vehicle move, as from a stop sign. The condition may cause the engine to stall if it's severe enough.

Fuel System Checks
- Check the fuel pressure.
- Check the throttle position (TP) sensor for binding or sticking. Voltage should increase at a steady rate as the throttle moves toward wide open throttle (WOT).
- Check the manifold absolute pressure (MAP) sensor response and accuracy.
- Check for water contamination in the fuel.
- Check the canister purge system for proper operation.
- Perform the fuel injector coil test.
- Perform the fuel injector balance test.
- Check for low fuel pressure after a cold start or during a moderate or full throttle acceleration.

Ignition System Checks
- Check for damaged spark plug wires.
- Check for fouled spark plugs.
- Check for proper ignition system performance.

Additional Checks
- Check the Service Bulletins for calibration updates.
- Check the generator output voltage.
- Check the EGR valve operation.
- Check for a restricted exhaust. "
Old 09-15-2005, 07:56 AM
  #3  
Restricted User
iTrader: (1)
 
woodman13's Avatar
 
Join Date: Jun 2004
Posts: 49
Likes: 0
Received 0 Likes on 0 Posts
Default

4.3's with 100K miles tend to have a carbon build up in the top end from lack of oil changes and poor quality oil. I had same issue, I pulledd it apart and resealed it and cleaned the carbon out and presto like a new engine. Still driving today after 80K more miles.
Old 09-15-2005, 11:54 AM
  #4  
TECH Fanatic
Thread Starter
iTrader: (13)
 
redbandit98's Avatar
 
Join Date: Feb 2004
Location: Ft.Smith AR
Posts: 1,164
Likes: 0
Received 1 Like on 1 Post
Default

hooked it up to one of those new delphi systems my buddy uses at the shop he works for..it is state of the art and bad ***..its wireless and directly connected to the headquarters..it was like 40k!!! anyway turned out to be a poorly adjusted tps, the voltage was right on the edge of throwing the light..
matt
Old 09-15-2005, 09:37 PM
  #5  
ACW
TECH Veteran
 
ACW's Avatar
 
Join Date: Dec 2004
Location: Beaumont, TX
Posts: 4,012
Likes: 0
Received 1 Like on 1 Post
Default

Cool, glad it's fixed Heh... that was only second on the 'list', didn't need a $40,000 tool ( / ) for that
Old 09-19-2005, 11:30 AM
  #6  
TECH Fanatic
Thread Starter
iTrader: (13)
 
redbandit98's Avatar
 
Join Date: Feb 2004
Location: Ft.Smith AR
Posts: 1,164
Likes: 0
Received 1 Like on 1 Post
Default

yes but its now fixed..i guess i could have checked it with my voltmeter but hell this thing is bad..its wireless and its about the size of a small notepad, you download all the stuff into it and it communicates with headquarters and gives you things to look at..for example ..say on a newer car that the fuel pump relay is connected somehow to the glovebox light..this softwarw will tell you, go to glovebox, open it,.if ilight is on , fuel pump is getting power, next step..its bad ***. its got a touchscreen and a pencil like a palm pilot. it also has built in tutorials of over 800 sensors..so if your customer has a question about a camshaft positon sensor it will let you touch the screen and it will go through a tutorial with pictures diagrams and everything, all wireless..he said that the cars now have like 200 sensors, and the future cars will have over 600.. this thing is set up to handle all of it..its the only one in state of arkansas right now.. it will also give you a printout of everything on the car and how its performing, its truley amazing what it can do.
Old 09-19-2005, 10:32 PM
  #7  
ACW
TECH Veteran
 
ACW's Avatar
 
Join Date: Dec 2004
Location: Beaumont, TX
Posts: 4,012
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by redbandit98
...
this thing is set up to handle all of it..its the only one in state of arkansas right now.. it will also give you a printout of everything on the car and how its performing, its truley amazing what it can do.
Very cool (And definitely lucky to be friends with that guy! ) Just curious, do you know what it's called / what company makes it? I found an ~$8000 diagnostic tool, but that's not nearly the same price level: http://buy1.snapon.com/products/diag...12&dir=catalog
Old 09-20-2005, 09:56 PM
  #8  
TECH Fanatic
Thread Starter
iTrader: (13)
 
redbandit98's Avatar
 
Join Date: Feb 2004
Location: Ft.Smith AR
Posts: 1,164
Likes: 0
Received 1 Like on 1 Post
Default

here is the link to there system..i dont know much about it or how much it cost..the price was their total price..i dont know what all they got with it but im sure its a shitload..

http://www.delphi-iss.com/index.asp?...23&refererID=2
Old 09-20-2005, 10:24 PM
  #9  
ACW
TECH Veteran
 
ACW's Avatar
 
Join Date: Dec 2004
Location: Beaumont, TX
Posts: 4,012
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by redbandit98
here is the link to there system..i dont know much about it or how much it cost..the price was their total price..i dont know what all they got with it but im sure its a shitload..

http://www.delphi-iss.com/index.asp?...23&refererID=2
Cool, thanks for the link



Quick Reply: 4.3 liter vortec hesitation problems



All times are GMT -5. The time now is 02:37 PM.