Reduced power?

There should be codes stored, go to Autozone they read em for free, post the results here. If no check engine light, or no codes stored, check for power to the PCM. Check all fuses under the hood, marked PCM or ECM....This guide will help us fix it

https://www.2carpros.com/articles/reduced-power-limp-mode

Please run down this guide and report back.

the ecm last year went into back up timing mode do to extreme exhaust leak. since then all repairs have been made. no diagnostic equipment was ever used to read or clear the ecm, resulting in several months of off and on limp mode.this happened in winter, at temps. of 32 degrees or o degrees celci us. now the same time of year and temperature the 3.2litre 1992 tropper was running great, came out to start it and it would only turn over. also the heater is not working yet all fuses in and out of vehicle have continuity. my question to you is can it be possible to restore the ecm's internal internal clock to a time pryer to these events or some other method without the use of any dianostic tools
.

https://www.2carpros.com/articles/odb1-isuzu-1985-1994-cars-and-trucks-code-retrieval-procedure-and-definition

Check aboce link on how to retrieve trouble codes and let us know what they are.

tropper stuck in limp mode. all repairs have been made. is the only way to clear the ecm is with a diagnostic scanner, because unhooking the battery dont work. help please

If a fault has been detected and not rectified, resetting is futile. You need to retrieve the trouble code and proceed from there.