[Mr Bear]

All done. So far, seems all successful. After a 30 mile test run, it appears to be gas, oil, coolant and vacuum tight.

Got up and went out at 830 (24.5 hour cure on the RTV on the intake ends) and filled Pixie with coolant. Checked for any leaks at the freshly tightened frost plugs and the pesky drain that always weeps on a plastic radiator (I have long since learned to pack the drain threads with a bit of soft setting pipe sealer in addition to its rubber o-ring), and every thing looked good.

With some light trepidation, I got in, set the park brake and turned the key. Two turns and Pixie fired up and settled into cold high idle. Let her run for 45 minutes with the heat on high checking everything for leaks....couldn't find any.

So, took her for a 30 mile run on the highway and noted a high hot idle. Usually she idles along at 650 rpm.....it was up around 750 to 800 and the throttle pedal felt stiff. Otherwise no issues. Check engine light is on but I expected that after replacing so much stuff and having powered it up with the battery install before reconnecting the MAF sensors. It should clear in about 75 miles of driving or several warm/cold cycles. If not, I'll check with the OBD reader at Oreilly's.

In the meantime, the combination of MPFI and the throttle body mod made the low range torque come on much better. She no longer works hard to climb the hills out of the neighborhood in lower gears, acceleration is better, idle is smoother and the hot restarts are instant, no lag with the new injectors.

Got back to the house, checked again for leaks and none noted. So....changed the oil and wix filter. I went ahead and switched to 5W30 full synthetic since its a fairly high mileage engine.

I took off the air cleaner hat and looked at the routing of the throttle cable. Had it on the wrong side of the PCV valve assembly adding an extra bend. Put it back where its supposed to be and the throttle freed up. In addition, with the reroute of the cable RPM at hot idle dropped back to a comfortable 700 RPM, only slightly higher than the usual 650ish it used to run.

It seems I got it right.....for now!

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It looks like an unexpected side benefit of switching to Mobile 1 Synthetic oil (5W30) on this high mileage engine is an overall increase of oil pressure.

Regularly, Dinosaur Oil provided me hot readings of 18 psi Idle and 35 psi at Speed.

It would appear that Fake Oil is going to provide somewhat improved figures of 25 psi Idle and 45 psi at Speed.

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250 miles have rolled under Pixie's 10.5" wide tires and she's still idling 900 with an engine light. We idle along in traffic with the brake on to keep it below 30 mph.

So, came home this evening, sprayed out the Idle Air Control slot in the throttle body with carb spray. Some better....so, I did the idle relearn for the 275th time. 800 rpm progress, figured I'd give it another 100 miles and see. So, went hunting in the back yard, killed a doe and on the way to get ice and a cigar its idling 1500 and 1000 and 700 and 1800 and well, we limped home and processed the deer.

Took a shower and thought it over.

Went back out, fired it up, sprayed everything between the fender wells with carb cleaner and wd40 looking for vacuum leaks. None.

Shut Pixie off and yanked the IAC stepper valve out of the throttle body (had been to oreilly this PM and the single code was P0507, unexpected high idle...yeah, I already knew that. Unfortunately its a generic Diagnostic code with about many causes. But my problem wasn't on the GM list of causes). Anyway, the IAC valve was a touch cruddy, cleaned it....cleaned the seat, lubed the o-ring and reinstalled. Started Pixie....700 rpm....great....till I blipped the throttle....Pixie stuck at 1000 rpm.

Scratched my head. Scratched my belly. Could it be?.....

Pulled the air hat, got a flashlight and looked down on the throttle blade I had removed to modify (removal of the blockage to increase low and midrange torque).....

Flipped the throttle plate gently, sticky.....wiped it out...flipped it, sticky....right there at closing sticks. It can be forced closed but not under spring power.

Looked close, back half of the throttle has a gap as wide as a hair, i.e. not wide at all.

Could it be that simple?

Loosened the torx screws on the plate, bumped the throttle twice gently so the plate aligned.....retorqued the torx screws and flipped the plate again. No hair line gap on the back half and no sticky throttle.

Got back in the drivers seat, bumped the gas pedal, no sticking! Started Pixie, fired right up, settled in at 550 RPM. Shut down and started again three more times, same result....550 RPM idle.

I think its fixed. Test ride tomorrow and that pesky engine light should reset by itself now.

I'll let ya know.