7.3 High RPM problem

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Oct 12, 2024 | 02:23 PM

Sergeant Titmilk

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2nd Gear

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7.3 High RPM problem

I recently replaced the injector o rings on my 1999 F250 7.3, and as a result, I'm having trouble with high RPM. I used to get 600–700 RPM at idle now i get around 900 RPM, I get 2000 RPM at 60 mph when I was getting 1600–1700, and 2600+ RPM at 70–80 mph when I was getting just over 2000 RPM. Does anyone know what might be the cause of this?

I have a code P0269 - Cylinder 3 Contribution/Balance Fault. Could this be the cause?

Oct 12, 2024 | 06:25 PM

udsuth78

Lead Driver

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From: Ponca City, OK

I'd suspect you either missed a connector for a sensor or possibly damaged a connector or sensor while doing the o ring job. You need to check ICP and IPR DC% while running and see what the PCM is or isn't doing about the high RPM. Go ahead and check the RPM with the scanner too. See if it matches the cluster. Check the tube from the MAP sensor to the intake also. Maybe it has developed a leak or has plugged up with oil.

Oct 14, 2024 | 04:32 PM

truckeemtnfords

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From: Fallon,NV & Bainbridge OH

I won't speak to the higher idle but the other rpm's sound a lot like the OD is turned off, that is if you have an auto.(you don't have much info in your post or bio)

Oct 18, 2024 | 01:04 PM

Sergeant Titmilk

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2nd Gear

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Before I did my injector o rings and replaced one injector I was reading 2100 rpm at 70 mph, but I had 4 damaged o rings and a dead injector. Right now I'm not getting any engine codes or tranny codes. Could I have been getting lower than normal RPMs because of my injector problem? Is 2400 to 2500 rpm normal for a 4.10 gear?

Oct 18, 2024 | 02:14 PM

udsuth78

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From: Ponca City, OK

Quote:

Originally Posted by Sergeant Titmilk

Not sure since I don't have 4.10's but it doesn't sound far off. The tire size, terrain, even the weather can have a pretty big impact on RPM at a given speed. That idle RPM isn't right though, at least not for an engine that's up to temp. There's a question. What's the EOT reading on your scanner, and I don't mean the temp gauge in the cluster. Those things are not accurate in the slightest. It's not even wired to the PCM and is only there to make the consumer feel good that they have a gauge to look at, nothing more.

Oct 18, 2024 | 09:55 PM

JoshHefnerX

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From: Glendale, AZ

I have 4:10's and if I'm remembering 2250ish at 65 is where I usually drive. 70 comes in closer to 2400-2500.

Oct 19, 2024 | 06:36 AM

ESwift

CNCFAB

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RPM would not change with injector oring changes, etc.. once the tc is locked the crank is pretty much directly connected to the rear tires and speed/tire size dictate engine rpm in the gear being run
This will tell you what rpm you should be seeing depending on tire size.

https://www.crawlpedia.com/rpm_gear_calculator.htm