Rough idle and shuts off when the transmission is shifted into gear?

1993 CHEVROLET 1500
184,000 MILES • 5.7L • V8 • 2WD • AUTOMATIC
Avatar
ALWHO
  • MEMBER
  • 2 POSTS
The engine won't idle smooth shuts off soon as you put in gear.

I have replaced the following:

1. complete Distributor, Coil, Plugs, Plug wires.
2. Drop tank cleaned it and replaced the fuel pump, and frame filter.
3. Replaced injectors, fuel regulator.
4. Replaced the EGR, 02 sensor, Throttle sensor, idle sensor, vacuum lines, and every other sensor i could find.

Mainly since Trucks 30 years old and I have changed everything until now.
What am I missing? Help
Nov 12, 2023 at 8:58 AM
Advertisement
Avatar
JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Hi,

It sounds like low fuel pressure or a large vacuum leak. Have you checked to see if there are any trouble codes stored? This truck has an OBD1 system and doesn't require a scan tool to retrieve codes. All you need is a short jumper wire or even a paper clip.

Here is a link that explains how to do it:

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

Let me know if you checked for engine vacuum leaks as well as the EGR valve. If it is stuck open, that can cause this.

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Let me know.

Joe
Nov 12, 2023 at 8:40 PM
Avatar
ALWHO
  • MEMBER
  • 2 POSTS
I fuel filter and cleaned tank replaced fuel pump have replaced vacuum lines and EGR valve, also changed fuel pump and filter only is when i try to keep running is 34 and once 43.
Nov 13, 2023 at 7:54 AM
Advertisement
Avatar
FFEATHERINGILL
  • MEMBER
  • 3 POSTS
Code 34 is MAP sensor voltage, a circuit code. Prove the harness and if it checks good then faulty sensor or PCM.
Nov 13, 2023 at 5:31 PM
Avatar
FFEATHERINGILL
  • MEMBER
  • 3 POSTS
Double check your distributor timing, be sure to disconnect the timing spout connector before starting when timing it.
Nov 13, 2023 at 5:33 PM