I have a 1991 fuel injected GM 366 cu.in. on propane. It was running
excellent until a few days ago. It has very little power on start up.
After a few seconds on flat ground, it picks up speed quickly and
seems to run fine as long as I am in a certain rpm off idle. It starts
and idles good once it is warm. When it is cold, it idles a little
rough, but not too bad. I am getting a code 43 which means ESC curcuit
problem. I had installed a new knock and O2 sensor. I had measured the
voltage signal from the ESC module to the ECM and found it to be a
steady 9.2 volts. The book says between 8-10 volts is good. I was
thinking the ignition timing is in full or partial retard mode thus
making it sluggish until there is less load on the engine? I was
wondering if the ignition module which receives the signal from the
ECM could be causeing this. Any ideas?