hesitation, loss of power on inclines.

1993 CHEVROLET SILVERADO
220,000 MILES • 4.3L • V6 • 2WD • MANUAL
Avatar
JHARPER0701
  • MEMBER
  • 6 POSTS
My truck runs great while its cold. But once that engine temp rises and the engine is at normal temps, the engine light comes on. And once the light is thrown i almost instantly have less power (horribly noticeable on incline) and also it will hesitate and stumble during take off or acceleration (bad). It will sometimes gradually get worse the more miles i drive. Another thing that's odd. When ever I'm on an incline and I press down on the throttle it will feel like less power and when I let out a bit it will get a bit more power until I press back down. Then it does it again. Like I said it runs wow great while its cold. But once warmed up the engine light throws and begins to act up. Truck has a new map sensor, new engine coolant sensor. New thermostat. New plugs and wires. Fresh oil change . New fuel filter. Any help would be great. please HELP!
Apr 25, 2015 at 9:37 AM
Advertisement
Avatar
WRENCHTECH
  • CERTIFIED EXPERT
  • 20,761 POSTS
Have the stored codes read and post the specific code number here. Please go over this guide to get the codes


https://www.2carpros.com/articles/buick-cadillac-chevy-gmc-oldsmobile-pontiac-gm-1983-1995-obd1-code-definitions-and-retrieval-method

Please go over this guide and get back to us.
Apr 25, 2015 at 10:58 AM
Avatar
JHARPER0701
  • MEMBER
  • 6 POSTS
I can have that done later. But could you take a shot at what you think?
Apr 25, 2015 at 11:24 AM
Advertisement
Avatar
WRENCHTECH
  • CERTIFIED EXPERT
  • 20,761 POSTS
It does sounds like the fuel pump is going out to me.
Apr 25, 2015 at 11:26 AM
Avatar
JHARPER0701
  • MEMBER
  • 6 POSTS
And today it got so bad. From wanting to die and sputter and buck. I unhooked the map sensor and it ran better. But. Still no power. Disconnecting the map made it run 100 times smoother. But no power.
May 1, 2015 at 6:12 PM
Avatar
WRENCHTECH
  • CERTIFIED EXPERT
  • 20,761 POSTS
And all that accomplished is to set some false codes to totally confuse things once you do get the codes read.
May 3, 2015 at 12:12 PM
Avatar
JHARPER0701
  • MEMBER
  • 6 POSTS
OK. Over the weekend I was able to track down a code reader. Coming up a o2 sensor. Upstream I'm assuming. I don't have a down stream. I bought a new part to replace and cut the cat off. It sounds like sand inside. Assuming that's bad. So I'm replacing all of that.would the bad o2 sensor cause those symptoms?
May 4, 2015 at 2:39 AM
Avatar
WRENCHTECH
  • CERTIFIED EXPERT
  • 20,761 POSTS
All you need to do is give me the exact code number. Don't replace anything. Don't cut anything off.
May 4, 2015 at 2:48 AM
Avatar
JHARPER0701
  • MEMBER
  • 6 POSTS
13
May 4, 2015 at 3:34 AM
Avatar
WRENCHTECH
  • CERTIFIED EXPERT
  • 20,761 POSTS
That's a generic code for an issue with the 0/2 sensor circuit. It needs to be further troubleshooted to determine if it's rich, lean or not responding at all. If you suspect a plugged converter, you would need to do a pressure test at the 0/2 sensor hole.
May 4, 2015 at 3:42 AM
Avatar
JHARPER0701
  • MEMBER
  • 6 POSTS
OK. I did replace the o2 sensor. And removed the cat. The cat was half fried. I replaced the sensor. It is still hesitant. And stumbles. Could this be a bad fuel pump? Or clogged fuel lines? Remember it only acts bad after it warms up.
May 5, 2015 at 8:32 AM
Avatar
WRENCHTECH
  • CERTIFIED EXPERT
  • 20,761 POSTS
Yes, it could be the pump causing all of these issues.
May 5, 2015 at 8:54 AM
Avatar
JHARPER0701
  • MEMBER
  • 6 POSTS
Yep, it was the fuel pump thanks for the advice.
May 5, 2015 at 9:08 AM