Truck at startup idles between 2,200 and 2,400 RPMs

1995 FORD RANGER
200,000 MILES • 4.0L • V6 • 2WD • AUTOMATIC
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EWC177
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Tried to reset new IAC and PCM. didn't work. checked screw under throttle, it's nearly all the way in. changed MAF, TPS, fuel sensor,all o2 sensors, catalytic converter, manifold, all vacuum lines,and replaced fuel pump,pressure regulator,fuses,and other things such as coil, plugs,and wires. starting to run out of patience and money. any help will be appreciated.
Apr 11, 2021 at 5:14 PM
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ASEMASTER6371
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Good morning,

The base idle screw being all the way in has raised the idle very high. With the IAC motor disconnected, the idle should be 500 RPMs.

https://www.2carpros.com/articles/engine-idles-too-high

I would clean the throttle body of all carbon deposits to be sure the plate is closing all the way.

https://www.2carpros.com/articles/throttle-actuator-service

Roy
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Apr 12, 2021 at 4:32 AM
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EWC177
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Throttle has been completely removed and cleaned with throttle cleaner, and the plate screw was originally all the way in, and it was worse..
Apr 12, 2021 at 6:04 AM
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ASEMASTER6371
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Again, if it is all the way in, it will raise the idle. It should not be all the way in, it should only crack open the plate a small amount.

Roy
Apr 12, 2021 at 12:41 PM
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EWC177
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It's only in about a thread or 2, and it's still idling around 2,300 RPMs.
Apr 12, 2021 at 2:31 PM
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ASEMASTER6371
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Can you attach some pictures and a video?

Roy
Apr 12, 2021 at 2:38 PM
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EWC177
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I'll try to upload some tomorrow after work, didn't check my emails before it got dark here.
Apr 12, 2021 at 6:07 PM
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ASEMASTER6371
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Sounds like a plan.

Roy
Apr 12, 2021 at 6:10 PM
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EWC177
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Thanks.
Apr 12, 2021 at 6:11 PM
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ASEMASTER6371
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Also. Unplug the idle air control and see if the idles comes down.

Roy
Apr 12, 2021 at 11:03 PM
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EWC177
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Tried that, and it didn't.
Apr 13, 2021 at 3:47 AM
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ASEMASTER6371
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Look for any vacuum leaks especially at the brake booster. If it is good, then I suspect the throttle body itself.

Roy
Apr 13, 2021 at 4:00 AM
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EWC177
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RPM checked with odb 2.
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Apr 13, 2021 at 5:48 PM
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EWC177
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2nd video.
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Apr 13, 2021 at 5:51 PM
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EWC177
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After reconnecting IAC and TPS.
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Apr 13, 2021 at 5:53 PM
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EWC177
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Vacuum leak.
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Apr 13, 2021 at 5:55 PM
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ASEMASTER6371
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This sounds like you need a lower intake manifold gasket from where you are spraying.

The valve you circled is the DPFE and that will not cause the leak.

https://www.2carpros.com/articles/replace-intake-manifold-gasket

I attached the procedure for you to view.

Roy
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Apr 14, 2021 at 12:32 AM
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EWC177
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Just had the manifold replaced, and new gaskets, twice..took to one less than reputable shop and paid over $300.00. then still had problems and went to another shop that works on everything and had to but new intake and gasket set because the others had left out the rounded bushing type gaskets...
Apr 14, 2021 at 2:47 AM
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ASEMASTER6371
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From your video, it points right to it.

Did they give it back to you that way after the repair?

Roy
Apr 14, 2021 at 3:58 AM
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EWC177
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Yes, it was running better, but would lag down if you dropped below 50 MPH.
Apr 14, 2021 at 4:13 AM
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EWC177
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Kind of a light lunge.
Apr 14, 2021 at 4:13 AM
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ASEMASTER6371
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Did they replace the upper and lower intake gaskets?

Roy
Apr 14, 2021 at 4:31 AM
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EWC177
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Yes, told me that they had a truck like mine and the surging was bad o2 sensors or stopped up cat on theirs, so they removed them..didn't help mine..now it has a new cat, muffler and all 3 o2 sensors have been replaced with the proper upstream and downstream sensors..
Apr 14, 2021 at 4:34 AM
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ASEMASTER6371
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With you spraying carburetor cleaner and the idle changing, you have a vacuum leak right there. Most of the time it is those gaskets.

Roy
Apr 14, 2021 at 4:41 AM