96 350 vortec back firing and loss of power

Asked by Dec 26, 2014 at 02:26 PM about the 1996 Chevrolet C/K 1500 Cheyenne Standard Cab SB

Question type: Maintenance & Repair

i have a 96 chevy 350 vortec. just changed the motor in it and cant get it to run right..it will
sit there and idle great when its it park...when i get out on the road it starts to loose power   
and back firing alot but only when i get to about 25-30 mph. help me under stand this.
took it to a shop they said i had a air leak in the intake,now there saying that  valves are
too tight...what is the problem?  you can email me at dustinjboshell@gmail.com...

5 Answers

68,435

Is it running hot as well? If so it's going to be a knock sensor problem. Sounds like the knock sensor is retarding the ignition timing. HTH. -Jim

no its not running hot at all... like i said i just bearly replace the motor with a long block from city motor supply in dallas tx...so its been at the shop for a week no and they keep telling me that its this and that but when the replace that part and put it back together its the same way as when i drop it off to them..... just trying to get some answers to why its doing this.... i read also about the cam retard offset... wouldnt that give them false codes if that was not set right???

68,435

It could give false codes but not necessarily. If the computer thinks that the engine is pinging it will retard the ignition timing. I had that happen to me on my '93 Caprice when it got old and develop a valve tap. HTH. -Jim

1 of 1 people found this helpful.

So your saying that it's the kn ock sensor.

68,435

It could very well be. The knock sensor is like a microphone. It "listens" for the engine pinging and retards the ignition timing until the pinging stops. If you have other noises going on near the knock sensor it may pick them up. On my Caprice the valve tap was right next to the knock sensor. With extremely retarded ignition or valve timing you'll get loss of power, popping back at the intake/throttle body, late transmission shifting (older models), and heat soaking. HTH -Jim

3 of 3 people found this helpful.

Your Answer

Add photo

Related Questions

  • 96 350 vortec back firing and loss of power 5 answers

    i have a 96 chevy 350 vortec. just changed the motor in it and cant get it to run right..it will sit there and idle great when its it park...when i get out on the road it starts to loose power and...

    1996 Chevrolet C/K 1500 Cheyenne Standard Cab SB

    -

    Maintenance & Repair

  • Loss of power, battery draining leading up to severe miss firing and back fire 2 answers

    Problem came on suddenly. I made no changes or additions to the truck. Then the voltage needle dropped from center at about 14 to less than half that. Had the battery/alternator checked they said th...

    1993 Chevrolet C/K 1500 Indy Pace Standard Cab SB

    -

    Maintenance & Repair

  • My 1994 Chevy c-1500 is stalling ,running rich, loss of power and will only go about 10 miles per hour and will stall out when you stop. 1 answer

    New distributor cap b/c it was screwed on, new TPS, while back changed TBI with used on but it was very clean! What could it be?

    1994 Chevrolet C/K 1500 Silverado Extended Cab LB 4WD

    -

    Maintenance & Repair

  • Firing 1 answer

    I was driving home from work and the truck died on the interstate. I replace the ignition coil it is still not firing. It's a 96 Chevrolet Silverado with a 4.3 liter V6 engine

    1996 Chevrolet C/K 1500 Silverado Extended Cab SB

    -

    Maintenance & Repair

  • 97 k1500 5.7 vortec swap with 95 5.7 350 ??

    i have a 97 k1500 vortec 350!! has 3 codes for cam 2 codes for crank how do i swap the 95 350 into the 97 truck ?? or what can i do to fix the vortec im at a loss idk what to do !!! HELLLPPPP

    1997 Chevrolet C/K 1500 Silverado Extended Cab LB 4WD

    -

    Maintenance & Repair

C/K 1500

Looking for a Used C/K 1500 in your area?

CarGurus has 882 nationwide C/K 1500 listings starting at $1,950.

ZIP:

Search Chevrolet C/K 1500 Questions

Chevrolet C/K 1500 Experts

#1 Andrew Olsen
Andrew Olsen
Reputation 3,460
#2 John Saffrahn
John Saffrahn
Reputation 2,530
#3 Rowefast
Rowefast
Reputation 2,110
View All

Related Models For Sale

Used GMC Sierra 1500
788 Great Deals out of 68,701 listings starting at $1,800
Used Ford F-150
2,162 Great Deals out of 195,111 listings starting at $290
Used Chevrolet C/K 2500
199 listings starting at $6,499
Used Dodge Ram 1500
417 Great Deals out of 10,946 listings starting at $1,000
Used Chevrolet Tahoe
597 Great Deals out of 32,881 listings starting at $1,500
Used Toyota Tacoma
516 Great Deals out of 43,168 listings starting at $1,995
Used Chevrolet Camaro
349 Great Deals out of 31,370 listings starting at $2,500
Used Chevrolet S-10
9 Great Deals out of 1,309 listings starting at $1,999
Used Chevrolet C/K 3500
232 listings starting at $2,500

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.