1. Check for boost leaks.
2. Kinked/damaged exhaust system?
3. Get a bigger turbo.
A 62/65/14 would do and have great spoolup. Second choice would be a 62/71/13 or 14. Don't know if this would spool for your liking though.
I have the wastegate plugged on mine and it hits 45 psi now and then. Have 180,000 miles on my original head gasket and still counting.

 

My truck is turned down now,
The #8 plate was shifted all the way forward toward the engine, and the AFC only had three bolts, but it was tight. I was thinkling maybe it loostened up and was part of the problem. I also took off the back of the AFC by breaking off the bolt, and checking the diaphram for holes, tears, etc.
I moved it toward the firewall about 3/16''. And of course replaced the bolts.

My truck takes about 2.5 times longer to warm up to operating temp. in the morning now, the max egt I am seeing now is 1200 when shifting into o/d with my foot buried in it. Less smoke, and less power of course. Boost also came down as well.

Still have not hooked onto the trailer though. Have not had the chance to work it yet for the ultimate test. Hopefully I got it now. Atleast I am not taking steps backwards yet.

 

I know its been a while, but I got it hooked on to my toy hauler with two one ton rock crawlers and hit the hills... I got it up to about 210* or so on the water and hit 1350* or so on the egt's. Did a good job on turning it down. It hink I'll stick around here until I get the turbo upgrade. that next stage is wqhere its going to start co$ting!!! thanks for the good advice guys.

 

Glad to hear you found the problem. One more question though.

Are you sure the t/c is locking? If it does not, the trans fluid will heat the coolant enough to show the engine is running hot when it is actually the trans running hot.

Just want to be sure.

Ronnie

 

Let me guess crucescrawler = Las Cruces? If you need any help tracking boost leaks or anything let me know. I have a device to find them, I also have a 62/65/14 turbo for sale among other things. PM me if you'd like.

-Dustin-

 

I believe the 98 to 98.5 12valve has a catalytic converter then they switched to 24v without the cat mid-year. These can easily plug up and cause enough backpressure to heat things up in the engine. Have you already tried "testing" with a piece of straight pipe? I know the heating effect is so great that Ford even has a "warm up exhaust valve" to heat engine & cab quickly in the great white north here.Those with an exhaust brake will know this as well should they ever bypass the throttle switch so it can be activated while dialing for fuel in cold weather.

In short the engine may be constipated and may need an enima.

 

PM'd on the turbo! Las Cruces is right...

 

I have 5'' stacks straight. No cat/exhaust restrictor plate.