Interesting idle issue

[JSchuricht]

So I finally added a chip to my 95 only to have a weird issue. I am working with the tuner on the issue but I am not completely sure I can rule out the truck as the cause of the issue.

Here's the issue... basically a stock 95 built 10/94 with a TEE4 PCM, no issues prior to chip install. With the chip installed, 30° f outside starting the truck in stock I see 600 RPM, in the tow or performance tune I see 1000 RPM. Same setup with it 50° f outside and I see 800 RPM. The thing is this isn't the normal cold idle, I can hold the brake and drive around at the same idle RPM till the truck warms up then it's back to 600 RPM.

The only similar issues I have seen are here 1 2 but have no solutions. Has anyone else run into this issue? The reason I question the truck is the chip and tunes have been used in many other trucks so I am thinking I must have some weird combination of parts or issues.

[BigFuel]

It can still be the tunes on the chip. Might just be a bad write error or something. Then again different trucks do really weird things with common/proven tunes. Mine will not start in Eco and it idles 200RPM lower then in the other tunes. Only at idle do the tunes have to be absolutely perfect. If you have one strong or weak injector or an aging HPOP then the tuner will have to continue to mess with the tune till its just right. Sounds like the tuner is working with you, just be patient and let him work his magic.

[Carpenoctum]

I have a DP Chip on a 03 7.3 and when it's cold and in a performance setting it increases the hpop pressure till it's warm than it matches the stock pressure. Not sure why either but it makes it noisy