Windsor 90 Laredo

I like how this forum has greatly helped in letting me fix up my jeep without paying a mechanic. No offense to professionals, just broke usually. I have a '90 Laredo 4.0 (renix) came with a small lift, 32.5 tires (that are twelve years old), and bullet holes. Bought for 400$ and am very happy with it. 400$ is cheap for where I live. I've been chasing the infamous random high idle issue. Upon recently checking the tps voltage numbers, after checking its ground connection and the TB for carbon. I suddenly had to drive somewhere and drove with the tps adjusted low. I needed .82 volts and I left it at like .26 but the high idle hasn't returned since. Does anyone know if I'm causing harm to any other parts by driving with the tps way out of adjustment?
The other issue is my antifreeze reservoir bottle leeks a lot from the cap after driving. I recently put in a new radiator and thermostat, and the cap leak is happening now (about a month later). cap looks good and the bottle threads seem fine. I read one doesn't need to "burp" a renix cooling system, but it seems like air is trying to purge out hence the overflow. Has anyone modified their cap with Teflon tape or something to remedy this? I'm looking into metal resevoirs but I need a quick temp fix. Any ideas would be appreciated. Especially a way to test the cap. Sorry for the book.

djb383

Using the "search" function will show aftermarket bottle caps that work better than stock. The cap needs to hold 15-16 lbs to prevent coolant from boiling.

cruiser54

703-1396 cap from Napa.

Doing no harm with your TPS adjusted wrong I guess. Sounds like it needs replacement but you can't afford it?

Do posts 1,3,4 and 5 in my Tips from the pink link below.

Windsor 90 Laredo

I just put a new cap on the resevoir. Napa stores are closed on weekends so I got one from orielys for now. Got to the red on the heat gauge and coolant spewed from the cap, so maybe it's the bottle itself. I just noticed that the hole on top of the bottle had a screw to seal it that has been there since I bought it. Should the hole on top of the resevoir bottle be blocked? Their isn't a leak anywhere except from the cap. New thermo, new rad. Those have been in their for a month or so, and just yesterday its having overheat issues. Both rad hoses were hot, both fans work, and my shroud was cut down some by the previous owner but I don't think that's the case. If someone can shed light on the top hole of the resevoir bottle. That would be great. I'm going to work with my tps one more time before I replace it. And follow cruisers link steps. Maybe a good flush is all I need to do for the heat issue?