Okay here's as in depth as I can go about the problem. Was on my way to work and the car was beginning to overheat (been having radiator problems - got those all sorted out though), but it did not fully overheat, maybe about 3/4 the gauge, maybe a sliver more. Parked the car at work for 8 hours, got off, and as I went to start it she immediately stalls. I don't get the chance to gas it or anything. Here's what I know and what I've done:

Has spark - it's starting up and turning over fine - just an immediate (I'm talking like .5 seconds of run time) stall
Replaced the radiator and gave her a coolant drain/clean (old one snapped on the upper outlet due to bad coolant/age)
Replaced fuel pump, and I can hear it surge every time I turn her over
Replaced fuel filter - old was was quite nasty.. but not the problem
Replaced MAF as I was reading here that can sometimes cause the problem

Now my problem has not changed one single bit. I figured next I'm going to give my IAC a good cleaning, make sure it's not getting stuck. How about the coolant sensor? Would that cause the problem? I only ask because the last time she ran she was a bit hot.

A side note.. ran an OBDII before I changed the MAF (got one from Autozone that gave diagnostics reading, not a code) and the only two that came up were MAF and Air temp control. Upon speaking to the guy at Lexus, he informed me there were the same unit. Now, my dumbass didn't have the MAF plugged in when I ran the OBD.. so i plug it in and everytime now i just get a "synch read error" or some bullcrap telling me to turn the key "off" wait 10 seconds and turn it "on". I'm losing hope but will see what happens when I clean the IAC. Thanks in advance

 

that's as in depth as u can go? what year? no communication with the ecu?

 

It's a 96, sorry. From what I know, the ECU is fine. Also read a similar article hear from a few years back saying something about if the ECU is causing this problem, the check engine light does not come on upon turning the electronics on. Could have been false, but I checked that and it was fine. All fuses are good, fuel pump ECU seems to be fine, it surges. I'm narrowing it down, for right now, to either IAC or coolant temp sensor not reading right. I say those two options because it seems to me it's either leaning out too little gas or enriching it too much. Just won't hold the idle, whether the gas is floored, partial, or none at all.

 

disconnect the battery for 5 minutes..hook it back up. see if it still does it and also check for any codes

 

Did it 20 times. And like I specified before, my OBDII port is giving me reading errors. So I dug into that a bit and think I found the problem on a huge thread here regarding the ECU Capacitors. I hear the 95-97's are quite famous for having this problem. Gonna' check it out later when I get home to the car.

 

Especially from Florida... heat and humidity are killers for those ECUs... since you're not even getting the read from the ECU, I'd certainly start there. Good luck.

 

Thanks.. I'll need it. This is why my 4 previous cars were classics - don't need to be an electrician to fix them. But I'm going to pull an ECU from a junkyard in the meantime of waiting for the capacitors to arrive. Got my fingers crossed.

 

I'm going to post a series of pics, not sure the order they will be in but they are of my ECU and the capacitors. The damn thing looks brand spankin' new, no corrosion on any of the caps. Also got a general pic of the inside of the ECU. Please let me know if this problem can still persist through this.

 

Now the third pic here is the only object inside the computer that seemed to show any kinds of age, but it still looks decent, and it's not one of the capacitors. Eh?

 

And finally, I got the IAC off, and cleaned it up a bit with break cleaner (didn't have carb or intake cleaner on me). Little did I know this generation's IAC is one whole unit, and cannot be taken apart to furthur inspect. However, I did notice that the inside piece (I'm guessing the piece that allows the air into the engine) was opened up a bit, as you can see some brass coloring past it. Is this a normal setting for an IAC, or might she be stuck open a bit too far and enriching the engine too much? Or possible not opened up enough, therefore leaning her out too much. Really appreciate the help in advance.