Where do I find the minimum idle speed?
Remove the connector from the IAC valve (located below the TPS on the passenger side of the throttle body). Start engine. Check the RPM gauge for the proper idle speed setting (minimum air). This information can be obtained from Specifications, Tune Up Specs for any year you select.
What’s the minimum idle speed for a 1988 350?
For the car we are using (1988 350 AT), the minimum air or idle speed should be a 400 RPM. I highlighted the needle on the RPM gauge as well as marked what the goal for this vehicle should be at (400 RPM). If the speed is off, there is a torx screw on the side of the throttle body on the driver’s side.
How do you set the idle speed on a Torx?
Set the idle speed to specifications, rotating the torx screw clockwise to raise RPM, and counter-clockwise to lower RPM. Once again, the desired RPM and needle were highlighted for ease of viewing.
How to troubleshoot an automotive engine high idle?
The troubleshooting procedure for high and low idle conditions are similar, which are included in the following: Step 1 – If the check engine or service engine light soon has illuminated retrieving the diagnostic trouble codes could lead you in the right direction of what the problem is, or is related too.
What should the idle speed be on a GM TBI?
Insert a T-30 size Torx driver into the Idle adjustment screw that is located behind the plug removed earlier. Turn the screw to adjust the idle speed to 650 RPM +/- 50 RPM. Turn off the engine and disconnect the negative battery terminal from the battery using a wrench.
How can I check the idle air control?
To perform a rough check of the idle air control, remove the valve while reconnecting the wiring harness. While observing the valve with a flashlight, turn the key to the “ON” position, (DO NOT START ENGINE.) the valve should move slightly.
When to remove an idle air control valve?
Because of the nature of this valve (large air volume processed) it should be serviced when a tune up is performed to remove “coking” which will hinder the valve’s performance. To perform a rough check of the idle air control, remove the valve while reconnecting the wiring harness.
What should be the idle RPM of a car?
Typically, engines idle at about 600-800 rpm. Older engines may go up to 1200 rpm or more while warming up. But if the engine is revving up while idling, even after it’s sufficiently warmed up, you might have a problem.
Is it normal to have a rough idle?
This is definitely not a normal situation. If you are experiencing a rough idle or your RPM is running high, then there are a variety of reasons for why this could be happening. It is not always easy to diagnose the cause because there are so many factors involved here. Below are the top 5 causes that a mechanic would look for.