1999 Chevy Suburban C1500 - Stumper

[shultzee13]

5.7L - 350 V8
2WD

Problem: Dies when stopping, turning corners. No codes given

What I've done:
1. Replaced Idle Air Sensor
2. Replaced Spark plugs and wires
3. Replaced Ignition Control Module
4. Replaced throttle position sensor
5. Replaced crank shaft position sensor

6 Months ago I replaced:
Distributor, cap and rotor.

Feels like it has a miss between 1st and 2nd gear when shifting.
Everytime it dies it cranks right back up. I think this eliminates a fuel issue.
I have sprayed brake cleaner everywhere on top of the engine, no change in rpm, except the normal miss the engine is already doing.

Possible Electrical issue?
Possible dirty throttle body?
Need to replace the throttle body?

Stumped.

[rkn463]

Originally Posted by shultzee13

5.7L - 350 V8
2WD

Problem: Dies when stopping, turning corners. No codes given

What I've done:
1. Replaced Idle Air Sensor
2. Replaced Spark plugs and wires
3. Replaced Ignition Control Module
4. Replaced throttle position sensor
5. Replaced crank shaft position sensor

6 Months ago I replaced:
Distributor, cap and rotor.

Feels like it has a miss between 1st and 2nd gear when shifting.
Everytime it dies it cranks right back up. I think this eliminates a fuel issue.
I have sprayed brake cleaner everywhere on top of the engine, no change in rpm, except the normal miss the engine is already doing.

Possible Electrical issue?
Possible dirty throttle body?
Need to replace the throttle body?

Stumped.

There is an idle air valve on the throttle body that it uses to add air at idle, they can get gummed up and not open and close as fast as needed. Check that. If it is good then I'd look for a way to monitor the fuel pressure.

Good luck!

-Richard

[DeadheadNM]

Having same problem intermittently with my 1999 Suburban 5.7 Vortec - did you ever resolve this and if so what was your fix? My motor has 116k miles and is otherwise in excellent tune. Thanks, Pete

[shultzee13]

For me Pete the fix was two things:

Replaced brake booster because I was loosing vacuum and there is a small Allen wrench adjustment on front of the throttle body. Never noticed until mechanic showed me after this post.