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Discussion Starter #1
When I start my 7.3 in the morning when temperatures are around 5 degrees Fahrenheit or lower, I’ll let the glow plugs heat up for at least 2 minutes (truck unplugged) and when the truck starts, immediately the rpms will be at 1500 with a rough idle and will slowly drop to about 1200. Unless this is normal, I can’t imagine this is good for the engine. Any thoughts? The truck does not do this when temperatures are slightly warmer. Thanks everyone!
 

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I agree that does not sound right or good to rev that quickly.
Typically high idle does not initiate for about the first 2 minutes after a cold start while vehicle is in Park (4R100) or when parking brake is set (ZF-5/6).

I will try and locate the correct procedure.
 

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Hopefully someone will confirm this also describes early ‘99 but there is no mention of an immediate high rev at cold start in Smokey’s thorough description below.

Are you touching the pedal at all during your start procedure? Is the floor mat possibly making the pedal stick?

 

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You should get some responses soon on what to troubleshoot.

Do you have a tune or does it do this on stock?

Does it happen when starting after the truck has warmed up also?

Do you have an EOT gauge?
My ScanGuage is always set to EOT in the winter.
 

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Discussion Starter #5
I do have a hydra chip now. I always run the fuel sipper mode. It does not do it when the truck is warm. I don’t have EOT or any gauges but I might buy a scan gauge very soon. Thanks Arctic.
 

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Can you change the Hydra to stock tune and see if the high revs continue?
 

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If it does it with the stock tune, try unplugging the icp sensor to see if that makes it go away.

Sent from my SM-N960U using Tapatalk
 

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Discussion Starter #8
Okay I’ll try that once it’s colder out again. It’s going to be in the 30s this week and the high rev doesn’t happen at those temps. I recently got a new OEM ICP sensor but possibly the pigtail is bad or I didn’t tighten it down enough?
 

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Discussion Starter #9
i believe you were correct with it being my hydra chip. I set it to stock and it starts very smoothly now and when I switch back to my daily mode the rpms jump slightly. I would have never thought! Thanks!
 

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Try starting with your chip in the 100hp tune and see if it romps for you...
 
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