1994 Chevy Silverado Loses engine power while driving

Tiny
NICKU2784
  • MEMBER
  • 1994 CHEVROLET SILVERADO
  • V8
  • 4WD
  • AUTOMATIC
  • 141,000 MILES
It is a 4x4 5.7L with a throttle body system, While at freeway speeds it more noticeable, If im holding it right at 70mph for example without moving the pedal it will lose power slowly, it will drop about five MPH then all the sudden power will come back and speed up. Also when im at a complete stop and give it alot of gas it just feels like there is a little four cylinder under the hood. Then all the sudden the V8 will come back and off I go. Some new or recently in the last year I have replaced.

Fuel pump
plugs, wires, cap and rotor
alternator
fuel filter, air filter (this past week) along with oil
I have taken off the muffler cause it was leaking and replaced it with a pipe, I think the catalitic converter is bad causr it rattles inside. I have cleaned the throttle body well, and I was told to take off that canister that hold all that carbon build up and blow it out. Well that didnt work so well. The hole was plugged and it exploded in my hands. Does anyone have and suggestions? I dont have alot of money and need to do this myself. Thanks
Do you
have the same problem?
Yes
No
Friday, January 29th, 2010 AT 11:25 AM

10 Replies

Tiny
SCOTTY DEE
  • MEMBER
If you hear rattleing in the convertor, and it's not the sheild making nose, there could be convertor material that gets in the wrong place at the right time. I would at least remove the convertor and pipe and see if it's restricted or if material falls out one end of the pipe.
Was this
answer
helpful?
Yes
No
Friday, January 29th, 2010 AT 7:59 PM
Tiny
NICKU2784
  • MEMBER
WOULD THE CATALITIC CONVERTER REALLY MAKE IT FEEL POWERLESS? CAUSE IT FEELS LIKE IT POWERED NY A FOUR CYLINDER ENGINE OR SOMETHING.
Was this
answer
helpful?
Yes
No
Saturday, January 30th, 2010 AT 11:22 AM
Tiny
SCOTTY DEE
  • MEMBER
Yes, If, IF, the convertor is plugged. I have dealt with quite of few clooged convertors on these models, usually after 10 years of service.
Was this
answer
helpful?
Yes
No
Saturday, January 30th, 2010 AT 12:48 PM
Tiny
NICKU2784
  • MEMBER
Ok so the best way to check to see if it is clogged is?
Was this
answer
helpful?
Yes
No
+1
Saturday, January 30th, 2010 AT 1:43 PM
Tiny
SCOTTY DEE
  • MEMBER
With a back pressure gauge pre convertor at the O2 sensor port, or unbolt it and shake it, if you hear a bunch a crap inside it, it's clogged.

Use plenty of penetrating oil on the exhaust manifold bolts, they have springs around them. If any break, you can get replacements at the parts store.
Was this
answer
helpful?
Yes
No
Saturday, January 30th, 2010 AT 2:40 PM
Tiny
NICKU2784
  • MEMBER
Thanks, I will be doing that in the morning.
Was this
answer
helpful?
Yes
No
+1
Saturday, January 30th, 2010 AT 6:52 PM
Tiny
SCOTTY DEE
  • MEMBER
Good deal. Let me know. Did you give feedback?
Was this
answer
helpful?
Yes
No
+1
Saturday, January 30th, 2010 AT 7:02 PM
Tiny
NICKU2784
  • MEMBER
Yes I did give feedback, I went out to take it for a drive this morning and well its gotton worse somehow. I didnt chabge a thing and now it will barely move, it runs rough under load, it seems normal in park, but when I give it gas it wasnts to die and when it does finally move there is no power and it will barely move fast enough to get to second and when it does it shifts kinda hard. I noticed a funny kind of metal on metal rubbing sound when I started it in the garage this morning. When I went underneath it seemed to be by the tranny or transfer case, it was in 4x4 when I started it. Wow this sucks, any ideas?
Was this
answer
helpful?
Yes
No
+1
Sunday, January 31st, 2010 AT 11:21 AM
Tiny
SCOTTY DEE
  • MEMBER
Okay, do this, take the O2 sensor out of the pipe pre-convertor, and run it down the road for a test. By removing the O2 sensor, if there is a restriction, it should run better. Let's try this first, and then we'll move on if needed.
Was this
answer
helpful?
Yes
No
+1
Sunday, January 31st, 2010 AT 11:33 AM
Tiny
NICKU2784
  • MEMBER
Thank you for your help. I decided after this to bring it to my friends shop. Its too cold to be wrenching on this outside. Your pretty good, keep up the good advice. Thanks again.
Was this
answer
helpful?
Yes
No
+1
Sunday, January 31st, 2010 AT 7:27 PM

Please login or register to post a reply.

Recommended Guides