The ACT sensor should be on one of the runners on the lower intake manifold.

The ECT sensor should be on the lower intake manifold near the thermostat housing. There is a second coolant temperature sensor with just 1 wire also installed near the thermostat housing, but it's for the temperature gauge.

 

Thank you!

I did spot the 1 and 2 wire ECT sensors, but I think I'll need to remove some stuff to see the ACT sensor. I got coming from Amazon two new 2-pin temperature sensors - one for charge air and one for engine coolant. I might as well replace them both while in there since both are throwing codes.

Also going to try a new TPS because she loses all power when I reach about 75% throttle position, even just starting out in first gear from a stop sign.

If that doesn't fix I'll have to hookup the remote pressure gauge (Wires to my windshield wiper so I can see it while driving) to the fuel rail and make sure fuel pressure is increasing correctly with throttle.

Thanks & have a great day!

 

Jesse, you may want to check this thread here about an unused Connector somewhere behind the Alternator.

 

You are correct, the ACT sensor is driver side on the top air passage behind the idle air control valve. If you prop open throttle you can look in there and see the ACT sensor way in there on driver's side!
The other plug hanging free is not for the ACTs.

What's funny, is the unused plug that is near the ECT plug but has a longer wire has the same keying (just different color of plastic) - so there are two plugs there that BOTH will fit the ECT sensor, and both reach it. But one is just long enough to reach ECT and the other is a bit longer than needed to reach the ECTS. The long one must have been for outdoor air temp or something.

So for good measure I cleaned the plugs and bent in the plug terminals a little for a better connection and replaced the ACTs, ECTs, and TPs, and since my ohm meter tells me that the old temperature sensors were still good (~50k on a cold rainy day) I plugged in the old water temp sensor into the stray unused plug since it fits HA.

That got rid of the ECTs/ACTs error codes (which were constant.)

Now I'm down to the following transient codes:
(When I jumper the code mode and turn the key on, first it blinks out "1 1 1" twice for current faults, then pauses and goes into "Stored faults mode" and gives:

172: "O2 Lean, not switching."
185: "MAF Lower than expected"
186: "Injector pulse longer than expected, OR MAF lower than expected"
187: "Injector pulse shorter than expected, OR MAF higher than expected."

It is running better than it was but still loses power at full throttle, so either my fuel pressure,flow is too low or my MAF is under-reporting at higher flow rates. It runs so good up to 70-80% throttle position though, it'd be odd that the MAF was reporting slow flows correctly but not high flows.
I wonder if my fuel pressure regulator is stuck.

I assume this is my best reference for the meaning of these blink codes: https://www.therangerstation.com/tec...des/#gsc.tab=0

Cheers!

 

I'd bet MAF is the issue. The fuel pressure regulator is barely doing anything at nearly full throttle. Running fairly rich wide open isn't gonna make a vehicle run like crap unless you waaaay over do it and the fuel systems on these aren't really capable of that at peak power.

Pull the spark plugs. They should make it obvious whether it's running chronically rich or chronically lean.

 

I agree, MAF is at top of my suspect list!
The reason the FPR is on the list is because it is a bypass-mode regulator, at low fuel consumption its little valve is partly open letting all the unneeded fuel flow back to the tank. If it were to stick open, or if there's some chunk of crud stopping it from fully closing, it would limit the fuel pressure at higher flows - and especially considering that the computer expects the fuel pressure in the rail to rise by 14 PSI at WOT plus the fuel demand goes way up and this would all cause it to starve out at or near WOT, so it's worth checking since I can do it for free and a new MAF is $80! (Which I will clean before replacing for sure..)
I did replace the one plug that had cracked ceramic and it looked OK for color.

Thanks and have a great day! Hopefully today I'll get a chance to spray out the MAF and see what we get!

 

Unless you have a failed fuel filter, the likelihood of crud in the lines is pretty low.

I will mention that one time after I installed a new fuel filter, the van started to occasionally lose power. It usually happens right after hitting a bump in the road, so I suspected the fuel filter had a loose object that would get in the way of fuel flow. I replaced it with the old filter, and the van ran great afterward.

I also say a case where the fuel pump was failing but it could still support the engine at idle, but the pressure dropped a lot when the engine was under load, and the engine would start knocking due to running too lean.

 

You bet correctly!!!

As you know the MAF has those two tiny thermo-resistor elements. Seems one had a broken wire but was mostly touching. I guess max airflow blew on it enough to make the connection spotty.

Anyway put on a replacement old used OEM MAF a friend had and now it runs great, has so much more power now than it did before too.

Thank you!