1990 Dodge Caravan bogs after warm up

I've replaced the fuel pressure regulator. And the fuel pump. I've got no trouble codes. In my experience if I had a sensor problem it would be reading out in the trouble codes. No?

Nice list. But why leave out the SBEC? Or the kitchen sink either?

The van runs great until it runs slightly over normal heat. Then starts the bogging. I can shift to neutral. Key off and restart. And the prblem will disappear for a bit. Then repeat.?

What's the possibility it could be a bad ignition switch?

Btw..I'm ruling out the cap and rotor since it doesn't have either. I don't know a single chrylser product with a cap and rotor since ' 89 eh.

Thanks anyway.

Since this problem only occurs when I encounter slightly elevated temps outside [heat wave here in the south. Btw]. And only after about 25-30 minutes of freeway-speed driving. I don't know exactly how i'd rig a test on the ignition switch to match those conditions. Do you?

What I did was tear into it to get to the switch. And after disaaasembilng the drivers' side under panels. Breaking down and disassembling the tilt column. And dropping the steering column. And tryingto get my test gear into position. I thought: what the hell am I doing. It's a 20$ part. So I replaced the ignition switch. And the lock cylinder [19$. Both were OEM parts.20 yrs old]. And the problem has disappeared. I'm now running fine.

So. For others reading. When this problem first appeared. I replaced the fuel pressure reg because it was slightly below spec. [Also orig equipment. Then on test found low fuel pressure. So we replaced the fuel pump as well. [Looked like original mopar pump]. Then replaced the TPS. Then finally the ignition switch. Every little thing helped. But problem didn't disappear until we replaced the ignition switch. I suspect it was overheating and forming too much resistance. Then spreading havoc through the system.