1999 Chevy Silverado Idling

Tiny
Z71_PILOT_1
  • MEMBER
  • 1999 CHEVROLET SILVERADO
  • V8
  • 4WD
  • AUTOMATIC
  • 170,000 MILES
Truck with 5.3 wont idle right. Idles too low most of the time at start-up. Then sometimes Idles wide open at start -up. No codes
Do you
have the same problem?
Yes
No
Wednesday, April 22nd, 2009 AT 5:18 PM

9 Replies

Tiny
JACOBANDNICKOLAS
  • EXPERT
It sounds like a bad throttle position sensor or idle air control valve. Without a code, it a guess. Have you checked closely for vacuum leaks and intake leaks?
Was this
answer
helpful?
Yes
No
Sunday, April 26th, 2009 AT 12:23 PM
Tiny
Z71_PILOT_1
  • MEMBER
I bought an engine from a wrecked truck, and they used the old intake because they said the newer one was damaged, I interchanged the IAC & TPS from both intakes and even changed the MAF sensor and neither fixed my problem
Was this
answer
helpful?
Yes
No
Sunday, April 26th, 2009 AT 1:22 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Was the year make and model the same?
Was this
answer
helpful?
Yes
No
Sunday, April 26th, 2009 AT 8:30 PM
Tiny
Z71_PILOT_1
  • MEMBER
Well since ya rarely seen the host vehicle for an engine in a junk yard, all I saw was the dogouse after the truck had been disassembled. I was told it was " the same engine ". The engine and intake appeared to be identical to the old
Was this
answer
helpful?
Yes
No
Sunday, April 26th, 2009 AT 11:09 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
If there is no check engine light, I bet there is an intake leak.
Was this
answer
helpful?
Yes
No
Monday, April 27th, 2009 AT 8:52 PM
Tiny
Z71_PILOT_1
  • MEMBER
Is that usually a difficult type leak to find/ fix?
Was this
answer
helpful?
Yes
No
Monday, April 27th, 2009 AT 9:05 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
I hate to recommend this, but with the engine running, spray starting fluid, carb cleaner. Around the intake. If there is a leak, the engine will rev up.

NOTE: WHEN DOING THIS, YOU ARE SPRAYING A VERY FLAMABLE PRODUCT ON A HOT ENGINE. A FIRE CAN START IF YOU HIT SOMETHING LIKE AN EXHAUST MANIFOLD. KEEP A FIRE EXTINGISHER NEAR.
Was this
answer
helpful?
Yes
No
Monday, April 27th, 2009 AT 11:16 PM
Tiny
Z71_PILOT_1
  • MEMBER
O.K. Thanks for all ur help
Was this
answer
helpful?
Yes
No
Monday, April 27th, 2009 AT 11:39 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Let me know what you find, and be careful.
Was this
answer
helpful?
Yes
No
Tuesday, April 28th, 2009 AT 8:19 PM

Please login or register to post a reply.

Recommended Guides