Hi guys!
My joy after my last T4R progress was too short, I have a new issue.

My T4R first gen 88 22re was running good, except for some rough idle once in a while I wanted to address, but nothing important (I want to believe). So I detailed the engine mostly with WD40, papers and cleaning rags because I didn't want to use water and degreaser yet. I needed the engine bay clean as much as possible to be able to check for vaccum leaks. After that I started the engine (it was still warm) and the idling was very low and stalled. The pattern is this now: after a couple of hours (engine cold) starts ok, but low idling/stalls with warm/hot start.

Lets google the problem, I said to myself... well, the list of possible causes, based in other threads, is very long: TPS, MAF, O2 sensor, spark plugs, spark plug wires, cold start injector, vaccum leaks, iacv valve, idle screw, fuel injectors, timming chain, cat, short EFI harness, fuel pump, my bad luck, etc.

So the question's what is the logic way to face this issue? I mean, I can start testing every possible cause, but I'd like to follow some logic if that's possible, what should be the order?

Please shed some light on.
Have a good day!

 

It had an idle issue (runs rough sometimes), you cleaned somethings and now it is worse..

They could be the same issue may not be. The first step is a general visual inspection that everything is still connected.

There is a diagnostics chart in the FSM, in theory, Toyota put these in order of likely hood.

The fastest simplest way to verify that many systems is the ECU voltage checks

 

Thank you, Co_94_PU.
FSM first, I'm going to upload this page for future reference.
I'm going to start testing tomorrow morning and I'll update this thread.

 

After an initial visual inspection, I found this covered with a piece of tape, the FSM called it solenoid resistor. Apparently it was poorly connected. I didn't meassure the resistance as the FSM suggests because it obviously has a problem
Could it be related to the issues I mentioned above?

 

Resistors are most likely good.
Toyota parts are bullet-proof. It's the connections that break. Perfect example here.

Try to solder it, OR repair like I did with coolant temp switch (TSW) connnector on my thread, OR replace connector with one with longer pigtail.

And don't forget to check crimps to ECU.

https://photos.app.goo.gl/xPH0FFMuXKblGwS72

 

Well: Disconnect the CSI, you do not need it unless its really cold. Next unbolt the EGR at the back or the intake and block it with a strip of metal from a soda or beer can, spooge and tighten. Next check the fuel pressure VSV on the back of the valve cover and make sure its wired and plumbed correctly. Check the air filter, then get a propane torch UNLIT!!! and dispense propane gas around all joints where unmetered air could get in. If it suddenly smooths out, that is where your leak is. If you wear a flame suit you are doing it wrong.

 

OR! Fix the wiring to the injectors so you have more than two tiny little wire strands trying to pass all that current to fire the injectors.

 

... thinking out loud ...why do that resistor is called Solenoid Resistor in the FSM? should be Injector Resistor....

Hi guys!

That wire was poorly connected, barely holding together by a few wire strands and covered with tape. I moved that wire when I was detailing/cleaning the engine and apparently that broken part got worse, causing the idle problems I mentioned in my first post in this thread. I didn't see it until I removed that tape.
I soldered it, I meassured the resistance, and it was good, I put it back, I reconnected the battery and started the engine. It runs as the way it was doing it before the problems, better, but I still have some engine shaking/hesitation problems I'm going to address soon.

Thank you Co_94_PU, RAD4Runner and skypilot, I appreciate your help.
Have a good day!

 

Cool! The injector is basically a a solenoid valve.; solenoid operating a valve.

Happy Easter, guys!

 

That explains it.
Happy Easter!