Third cylinder missing until RPM’s raised

Tiny
TONYNEAL
  • MEMBER
  • 2004 CHEVROLET COLORADO
  • 4 CYL
  • 2WD
  • MANUAL
  • 100,000 MILES
This truck has been one heck of a work horse since I’ve had it, about six years. Then I was helping a friend move some things, and while we were on the road (driving some what uphill) it started loosing power and then, missing badly in the third cylinder. But without a load I can drive it and once the RPM’s get higher it’ll smooth out, then when they start dropping it starts missing again and popping. Any ideas?
Friday, February 1st, 2019 AT 8:17 AM

4 Replies

Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Good afternoon,

How long since a good tune-up?

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

I would check the fuel pressure to be sure you have enough pressure.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

A compression test should also be done.

https://www.2carpros.com/articles/how-to-test-engine-compression

Roy
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Friday, February 1st, 2019 AT 8:47 AM
Tiny
TONYNEAL
  • MEMBER
  • 37 POSTS
Why would it smooth out on higher RPM's?
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Friday, February 1st, 2019 AT 9:00 AM
Tiny
TONYNEAL
  • MEMBER
  • 37 POSTS
Compression test = negative,
Air test = negative
Checked coil = negative
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Friday, February 1st, 2019 AT 9:07 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Negative? If you mean you did the tests, what were the results?

Roy
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Friday, February 1st, 2019 AT 3:08 PM

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