Clutch coil is easy to ohm out. You may want to check the wiring diagrams to see if the pressure switch is upstream or downstream of the relay. You may just be low on freon.

 

Success! The beast starts and stays running, achieves idle without any accelerator feathering, SAI does what it's supposed -- and no more MAF/IAT sensor codes.

So after 7 weeks and changing:

CPS
Fuel Pump
Coil Packs
Ignition Wires
Spark Plugs
etc.

and testing a bunch of circuits and relays for signal, continuity, etc., I finally decided to pull out my homemade paint can, mineral oil smoke machine (if anyone wants to know how to build one, there are youtube videos on it) and did more than just a visual and tactile inspection of all the vacuum lines I had originally done.

Viola, that elbow part of that fuel line style connector on the hose from the EVAP purge valve to the intake manifold had failed.

To test it quickly, I cut and ground a fuel line barb I had lying around to replace the original barb that had disintegrated, secured it in the connector with some 5 minute JB kwik weld, and everything is good now (even, the SAI, the operation of which must have somehow been affected by the vacuum leak). Can I buy that quick connect somewhere, or do I need to find one in a junkyard or just get rid of it and hose clamp that end of the hose directly onto the brass barb in the intake manifold.

FYI, when I started this journey 6-7 weeks ago, someone advised me in the first 24-48 hours of the original thread to check for vacuum leaks.

As Forrest Gump said "stupid is as stupid does".

 

Good news! At least you're back on the road, even though it was a long road to get there.

 

If you are referring to the elbow between the Evap valve and the top rear brass barb I would not sweat the details. The quick disconnect was likely more for assembly efficiency on the production line. You can go with just fuel line and hose clamps.

 

Yep that's the connector.

Went to Advance (closest to home), and they didn't have a vacuum "S" hose that I could use to eliminate the quick-connect, so guessing I will have to make my own.

 

Replaced the TPS and still no luck.

It wouldn't stay running when the temp got below 40 but will eventually run when above 50.

Today, I finally got ir running and the idle never stabilized: it searched for idle by breathing plus or minus 100-300 rpms (see attached)

And now it is throwing two new codes: in addition to on P0102 (MAF) and P18884 (IAT), it is now throwing a P0172 (rich Bank 1) and P0175 (rich Bank 2).

(BTW, I I have put in two new MAF sensors, I am starting to wonder whther my liberal use of dielectric grease on the connector might be the source of this problem as I thought I had read that the pinouts on these connectors are particularly sensitive)

Is that any clue as to what might be going on?

Makes me think it is a vacuum leak, still waiting on the new used throttle body to replace the one leaking at the shaft. (ordered from LKQ rather than going junkyard diving, they have been slow to ship).

And swapped out the fuel pump relay just in case (already replaced the fuel pump).

Still need to put in the new used underdash fuse box -- I got it unbolted but cant seem to pull it out enough to get to the connectors, do I need to remove that big junk of styrofoam straddling the steering column?

And ordered a new CMP (per the RAV, it looks like it can be replaced without removing the crank pulley, right?) and engine coolant temp as those are the only other sensors left to be renewed.

After all that is done, only thing left are the injectors (and ECM).

Thoughts?

 

OK, so today I replaced the under dash fuse box, and still having issues running.

Attached is a video I was finally able to get (my son is home; my wife refuses to help me with any having to do with cars) so you can hear the detonations/backfires I keep hearing when I work the throttle to try and keep it running.

So far, here's what I have done:

Changed:
MAF Sensor (twice, both new)
IACV (with a known good used one, though I note that both IACVs I have "hum" a lot more when key is in Position II than I remember -- could another IACV be next?)
CPS
Fuel Pump
Coil Packs
Ignition Wires
Spark Plugs
TPS
Fuel Pump Relay
Underdash Fuse Box

Smoke tested the intake:

Found a pretty major leak at the purge valve-to-upper intake quick connect (repaired)
Found a smaller but still discernible leak at the throttle body shaft (waiting for a new used one to arrive to swap out)

Parts still on the way:

CMP sensor (camshaft)
ECT (engine coolant temp -- the one on top of the engine behind the alternator)

After the last attempt to get/keep it running, I have three (3) codes: P0102 (MAF), P1884 (IAT, integrated with the MAF), P1668.

As the MAF(s) is new, I am wondering whether perhaps my liberal use of dielectric grease on the connector is contributing to the low MAF sensor circuit signal code P0102 (and the corresponding P1884).

Given the way it bucks like a bronco until I can work the throttle enough to get it to idle, then loses power after driving a few miles (anywhere from 2-10), I keep coming back to fuel delivery: next after all the above would be the injectors, but I assume if they were bad, then I would be throwing misfire or some other lean or rich codes?

Finally, I note that the SAI pump does not run as consistently/often the way I used to remember it: it has only come on sporadically during all of my almost 8 weeks of troubleshooting. The SAI pump is operational (I put 12V directly on it as well as jumpering it at the relay socket and I've tested the relay as well) as is the SAI valve solenoid (put 12V on it to confirm it opens). The SAI vacuum tubing all seemed to test out OK from the smoke test. To test the SAI valves themselves, I din;t do the rather involved test setup in the RAV, but rather I took the advice of someone on this thread and disconnected the SAI solenoid (so the valves should be closed), then pulled off the hosing on the pump side of each valve to see if I got any exhaust blowby thru the valves when running. I felt no exhaust blowby with the valves having no vacuum on them.

Most frustrating. ready to put a bullet in it. Or worse, take it to a mechanic

 

I had one D2 act up and never trigger a fault. Ended up being a bad purge control valve. Went with Hyundai unit & zero problems after that. Would be totally intermittent but the D2 would barely run, then clear up for a bit.

 

The P1668 appears to be some immobilization code.

After I swapped out the underdash fuse box, the alarm light was flashing with the doors opened, and it wouldn't turn over, so I cycled it a couple of times thru door lock-unlock states until the alarm light stayed off when the door was opened. Then it turned over fine (per above, running is a different matter).

Also read elsewhere that I need to sync the new underdash fuse box to the rest of the brain boxes. Is this the case?

 

So EVAP purge can fail and NOT throw a code? Hmmm.

I've replaced that EVAP purge valve once before at maybe 140K miles (with the Hyundai part), so maybe it's time again. Do you happen to remember the Hyundai equivalent part number?

A leak at that purge valve wouldn't show up from the smoke test as it vents somewhere in the back, right, so you'd never see any smoke around the intake manifold?

Can I just pinch it at the purge valve-to-intake manifold hose and see what happens?

And what do you know about the underdash fuse box and synching it (or not)?