Stalling at idle
Thread Starter
4th Gear
Joined: Jul 2023
Posts: 4
Likes: 0
From: Holton, Kansas
Stalling at idle
Hi everyone. I recently bought an 84, with an automatic. It has some issues with stalling. It runs at about 500 rpm and every 5-10 seconds it drops about 200 rpm and occasionally will stall. The previous owner said that it was caused by the IAC but I wanted to know if anyone had anymore information. I’m also curious if I need to replace it with a new one or if I need to repair it in some way? I have a CEL and there is a short somewhere in the wiring harness that drains the battery. Also I tried driving it to a friends house the other day and it stalled at a red light. Don’t know if that helps but wanted to mention it. Thank you!!
Safety Car
Joined: Nov 2005
Posts: 3,532
Likes: 1,185
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
Hi everyone. I recently bought an 84, with an automatic. It has some issues with stalling. It runs at about 500 rpm and every 5-10 seconds it drops about 200 rpm and occasionally will stall. The previous owner said that it was caused by the IAC but I wanted to know if anyone had anymore information. I’m also curious if I need to replace it with a new one or if I need to repair it in some way? I have a CEL and there is a short somewhere in the wiring harness that drains the battery. Also I tried driving it to a friends house the other day and it stalled at a red light. Don’t know if that helps but wanted to mention it. Thank you!!
Instructor
Joined: May 2023
Posts: 131
Likes: 1
Hi everyone. I recently bought an 84, with an automatic. It has some issues with stalling. It runs at about 500 rpm and every 5-10 seconds it drops about 200 rpm and occasionally will stall. The previous owner said that it was caused by the IAC but I wanted to know if anyone had anymore information. I’m also curious if I need to replace it with a new one or if I need to repair it in some way? I have a CEL and there is a short somewhere in the wiring harness that drains the battery. Also I tried driving it to a friends house the other day and it stalled at a red light. Don’t know if that helps but wanted to mention it. Thank you!!
the reason I’m bringing up fuel pressure is because I’ve been able to drive my car practically issue free up to 90mph/4500rpm with 6psi fuel pressure SOMEHOW. Just put a new pump in and waiting for the filter to arrive
Thread Starter
4th Gear
Joined: Jul 2023
Posts: 4
Likes: 0
From: Holton, Kansas
Take a fuel pressure test by connecting fuel pressure gauge to the Schaefer valve on the fuel rail with the car off. Make sure it’s tightened and turn the key on so accessory mode is on. Check the gauge it should be 40-45 psi range. You can check fuel pressure regulator by taking vacuum line off and if it’s dry it’s good. If fuel comes out it’s the regulator. You can check injectors with a multimeter. you should be getting spark since the motor runs, right? But it won’t hurt to check some of the plugs for rust or extreme carbon. You can also just listen on both banks of the motor for a misfire to narrow down the bank.
the reason I’m bringing up fuel pressure is because I’ve been able to drive my car practically issue free up to 90mph/4500rpm with 6psi fuel pressure SOMEHOW. Just put a new pump in and waiting for the filter to arrive
the reason I’m bringing up fuel pressure is because I’ve been able to drive my car practically issue free up to 90mph/4500rpm with 6psi fuel pressure SOMEHOW. Just put a new pump in and waiting for the filter to arrive
Safety Car
Joined: Nov 2005
Posts: 3,532
Likes: 1,185
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
Take a fuel pressure test by connecting fuel pressure gauge to the Schaefer valve on the fuel rail with the car off. Make sure it’s tightened and turn the key on so accessory mode is on. Check the gauge it should be 40-45 psi range. You can check fuel pressure regulator by taking vacuum line off and if it’s dry it’s good. If fuel comes out it’s the regulator. You can check injectors with a multimeter. you should be getting spark since the motor runs, right? But it won’t hurt to check some of the plugs for rust or extreme carbon. You can also just listen on both banks of the motor for a misfire to narrow down the bank.
the reason I’m bringing up fuel pressure is because I’ve been able to drive my car practically issue free up to 90mph/4500rpm with 6psi fuel pressure SOMEHOW. Just put a new pump in and waiting for the filter to arrive
the reason I’m bringing up fuel pressure is because I’ve been able to drive my car practically issue free up to 90mph/4500rpm with 6psi fuel pressure SOMEHOW. Just put a new pump in and waiting for the filter to arrive
Instructor
Joined: May 2023
Posts: 131
Likes: 1
You do not seem to know anything about an 84 with TBI in regards to fuel pressure. At 45+psi the car will be on fire as fuel pressure that high WILL busts the diaphragms. To the OP, DO NOT LISTEN TO THIS GUY. 13psi for a stock 84 IS GM spec. Get an 84 corvette GM service manual.
