In what has been a fruitless search for a cause, of why the 88 Cherk runs so rich/ poor/ MPG. I removed the plastic vacuum junction and, rerouted the vacuum lines. Cleaning up the circuitous paths considerably. Only to be rewarded with, a stalling condition and, no improvement in rich idle.. I'm sure my system holds vacuum. I've been all trough them and, pretty sure nothing leaks. I've replaced the TPS, and O2 sensors. A working set of injectors w/ new O rings, and ✓ed MAP line. I can do tests on electronic side of MAP as well as IPS. After that I'll run out of places to look. The only good thing is, I've become rather adept at using the digital multi meter.