Hi Scotty - long time fan - first time posting a question. I've owned my 1991 Chevy Silverado K1500 5.7 Auto 120K miles since 94'. It's a good truck experiencing an issue that first got my attention at the drive thru car wash which requires the vehicle trans to be placed in neutral. By mid-way thru the wash the engine will stall. Also engine stumbles during deceleration from speeds 40-50 mph. I've replaced the wires, plugs, cap, rotor, coil, idle air control valve. Problem continues. What's your advice? Thanks, Joe
This sounds like s fuel related problem. Check injectors, fuel filter, evap control system, throttle body and MAP cleanliness, etc. Check fuel pressure with mechanical gauge.
Thanks for the advice
try the simplest stuff first. Change air filter. clean out intake. Measure fuel pressure. Make sure cat isn't plugged up.
Does it have MPFI or is it still TBI?
Air filter is replaced. Back in 91 they were installing TBI and boasting about EFI.
Thanks for your advice.
ok make sure the injector is giving a good spray pattern too