Loss of engine power, stalling, failure to start when hot?

I finally had some time to check the ICM and coils. This unit is mount under the front exhaust manifold and is a beast to remove and replace. I discovered somebody had been there before me. One of the coils had been replaced with a used coil and one of the plug wire terminals was a ball of rust, and the rest of these terminals were clean. I did not like what I saw and since this coil/ICM were so hard to remove I decided to replace the whole thing. Got new parts a couple days ago and when about replacing and re-installing the coils and ICM. Got it all back together and started the engine. The engine started right up and was running very smoothly, about thirty seconds later the check engine light came back on. The engine continued running very smoothly, I listened to the exhaust and could not hear any misfires, but the sound of the exhaust told me the timing was still slow, acceleration of the engine was still sluggish. I thought I would test drive around the block to confirm if the engine as still sluggish as before. It was as sluggish as before. Halfway around the block the engine stalled out. I was afraid before to drive too far from the house for this very reason. While still rolling I cranked the engine and it restarted for 5 seconds and stalled again. I let it roll as far as it could. It stopped 3 houses away from home. I tried to restart it many times, but it would not keep running, it just starts and dies. I could hear it popping and spitting and backfire under the hood some, I also noted that while cranking from time to time the engine would push back on the starter like the timing was too advanced. I ended up pushing the car back home in 106-degree heat, Gets kind of warm down here in Texas these days. So far it has failed to restart and run. It might awhile before it cools down in this heat. From start up to stall out the engine about six minutes.
I just went outside to see if it would start up again. Current outdoor temperature is 107.
It still will only start and die. In this temperature it might not restart for a while.

Okay, the car finally restarted. First 4 attempts were start and shut off, 5th attempt it puttered for 4 to 5 seconds and shut off, 6th attempt it puttered stronger but was still just a putter, 7th attempt it started right and ran beautifully, no misfires, no puttering. I can still tell the timing is incorrect, when it runs semi-normal it seems as if you could drive it and only have the sluggish effect going on. It no longer runs rough like before. Apparently, there was some progress made by replacing the ICM and the coils. I think there is more than a single issue going on and masked under the code 43. The retarded timing alone should not cause it to abruptly stall and not restart until hours later like it did today. It's like something is somehow getting overheated and shutting down the electronics further upstream. Whatever it is slowly gets worse with each event. After today's stall out, I can no longer trust it leave it in the driveway. This is beginning to smell like one of those cars that might become a money pit. I'm not done or ready to give up on it just yet. When it runs right it is a sweet little car and pleasant to drive with very decent gas mileage. Speak out if anybody has any ideas of where to go next, hopefully not a new ECM.

I honestly don't know anything about this car's maintenance history. I was losing focus on the overall picture of the problems and concentrating on one issue. I changed the spark plugs because I did not know how long they had been in the engine. I guess I better get back to basics on maintenance and get the small stuff out of the way first. I don't know right now if the stalling is a fuel issue or electrical issue. I need to make it malfunction again to see if it is a loss of fuel or a loss of spark. Replacing the fuel filter may or may not resolve the issue but since I don't know the last time it might have been replaced, it certainly won't hurt anything. I derail myself! Thanks for waking me up, man. I could not see the forest for the trees! Now I will do what I should have done in the beginning. Test and eliminate instead of replacing parts blindly. I feel like a fool now!

09/09/2023. Got back to checking this car over. Temperatures here in Texas have been pretty warm and since I didn't need this car, I elected to not work on it in 106-to-110-degree weather. Until last night and today. First off, I replaced the inline fuel filter last night. The car has been sitting since our last conversation without any attempts to start it. I did not releave the inline fuel pressure just to see if it still had any pressure since it has been sitting so long. Cracked the line between the tank and the filter. It squirted gas out of the connection under some pressure. I found that interesting considering how long it has been sitting. Removed the other fuel line and saved the gas that was in the filter. Dumped the filter from one end to the other and gas would flow out both ends freely. I'd say the filter was not clogged up. Installed the replacement filter any wayand started the car. It took a couple of tries to purge the air and the ran normally. I decided to load test the engine under full throttle while in drive with the brakes applied while still in the shop. I know this is very tough on the transmission, but it's the only way test for the stalling malfunction. Note: under full throttle the engine can be heard misfiring. I could not really feel the misfires, but I could hear them very clearly echoing off the shop walls. That was something that surprised me. Flashback to the two spark plugs that were burning a very, very clean white? I held the throttle on the floor for about two to three minutes, suddenly the engine stumped like the key was turned off and on very quickly, what was that?
I let it slow down to idle, it was idling kind of weird but seemed good enough to keep going, back to full throttle for about another minute. Then the engine suddenly stumbled again and stalled out this time. I attempted to restart it. It only starts and shuts off and repeats. I left it alone until morning.
This Morning it started right up like normal again. Now I'm wondering is it a gas problem or electrical? I got out my fuel pressure test kit. Connected the pressure gauge and started the engine. Gauge revealed PSI at idle was 36LBS, sudden full throttle acceleration PSI was revealed to be 42LBS and quickly returned back to 36LBS. I think that is within the norms for this car.
All this testing of course caused the engine to warm up to operating temperature. While the engine idling, I heard a metallic click like a solenoid or relay click and suddenly the engine idling changed. I wondered if after reaching normal temperature if the idle slowed down? Then the engine began to shake slightly and shut off. The fuel pressure gauge was still showing 36 lbs when the engine stalled. I quickly installed a spark test light to check for ignition on the spark plugs. Yes, I still have ignition spark! Attempted to restart several times. No luck. I now wonder again if I have ignition and fuel why did it stall out. Then I thought, if the gas actually getting to the plugs. Quickly I removed the air filter and sprayed Berrymen B12 into the intake and attempted to start the engine. Hit the key and it started up for a couple seconds and died attempted to start it again without additional B12. It started up and shut off, started up and shut off. Gave it another shot of B12 and it started up and ran again for a few seconds until the B12 was burned out! I'm surprised but pleased to know the gas is getting into the fuel rail but what is stopping the gas from getting to the spark plugs after the car warms up? I think I also noticed the electric cooling fan may have stopped at the same time. I will check that out after the car cools down and restarts again later. That was some weird stuff and weird testing procedures to confer a loss of fuel just beyond the fuel rail. So, did something shut off the electrical pulse to the injectors? And don't forget that I think the cooling fan may quit at the same time. Can loss of the cooling fan cause this condition to shut down the engine? I will have to duplicate to test again watch to see if the cooling fan quits before the shutdown happens. Scratch your heads and let me know what you think. I know that as long as the misfire continues the knock sensor will keep the code 43 locked in and keep the timing retarded, but those white spark plugs really got stuck in my mind now. Got into my other test kit to check for a injector pulse from the ECM. The way this engine is built I can only get to one injector wire plug. All the rest of the injector wiring is under the air intake manifold. The engine has to run to warm up before the malfunction can occur.

I have already replaced the 3 coils and the ignition module and yes it will start up on starting fluid. I had stated that info above. To recap: after the spark plugs and knock senser, and temperature sensor, and coils and ignition module, and fuel filter were replaced I tested the fuel pressure. Running the test revealed 36 PSI at idle and under hard acceleration it goes to 42 PSI. I believe that is within the spec for this car. It stalled while I was testing the fuel pressure in the shop, never drove it down the street for fear if this very issue of stalling out. Fuel pressure gauge was still connected when it stalled. It was still holding at 36 PSI. While it was stalled it refused to restart and run. Only start and shut off, start and off. While in this condition of start and die I quickly installed a spark tester between the plugs and plug wires. It had a strong ignition spark. So, I saw the ignition source and I saw 36 PSI fuel pressure, but the engine won't keep running. I removed the air cleaner filter and sprayed Berrymen B12 into the intake. The engine started and ran until the B12 was burned out and stalled again. I tried to restart again without an additional amount of B12 being sprayed into the intake. It would start and shut off, start and off. I sprayed additional B12 again the engine started and rans a few seconds until the B12 again was burned out. I have not tested to see if the injector electrical pulse is working while this condition is present. That is the only thing I could think of as to why it stalled and shut off. ECM malfunction? What else could shut the injectors down? I know for a fact that fuel was in the fuel rail at 36 PSI (which it was running on moments earlier) and I know it has spark at the same time, but it refuses to keep running until I spray B12 or starting fluid into the intake. Not likely all 6 injectors quit at once. These are the things I witnessed when the malfunction/stalling occurred. This may or may not explain the misfiring I heard before the engine shut down.

Okay Ken. I looked at my options for testing and determined the only way I could access the injectors for testing was to remove the intake manifold. There is no other way to even see them let alone inspect the wiring and OHM test the resistance. During removal of the intake, I could tell somebody had been in there before. Loose and missing bolts and nuts. Getting down the facts. The #5 injector has been replaced and the other five appear to be factory installed. Completely remove the injectors from the engine and perform OHM test on each injector. Results as follows:
#1 10.5 ohms Out of spec
#2 7.2 ohms Out of spec
#3 12.2 ohms
#4 11.5 ohms Near the bottom of spec
#5 12.2 ohms Replacement injector
#6 12.2 ohms
The #1 and #2 spark plugs were the ones that I found to be very white, like new, out of the box type white. Note the ohms on those two injectors.
It might be that the PCM driver was getting overwhelmed. The link you sent me stated that one injector could cause issues with the other injectors and not show any additional fault codes. I only have Code 43 that is showing. I did not waste time to check the spray pattern. If the ohms are not within spec then I felt there was need to waste more time on spray pattern inspection. Will replace the set of injectors. #1, #2, #4 were very loose in the port hole. Most likely the o-rings were old and somewhat loose. I'm not sure this will cure the issues but I did see issue here and must correct them to keep moving forward. I will let you know when I get the engine back together. I will check the injector pulse at the injector wires before I re-assemble everything. But I'm sure it will test normal because the malfunction only occurs when the car is warmed up and it has to be running for that to happen. While I have it apart is there anything else I might check. Easy to do right now.

Thanks, Melton

Well, I finally had time to replace the injectors. I will skip the installation process due to boredomof story telling. After start up the engine struggled to idle for a few seconds till the air purged out. After that it ran smoothly. I have not been able to drive the car even out of the driveway for quite some time. I let it run for about 15 minutes and it did not stall, which it had been doing with great consistency. So I decided to venture out and see if it was going to stall while driving. It made the trip around the block for the first time in a while. I noted that the engine was running very smoothly but the check engine light was still on, and I could tell the timing was still retarded, but the engine was running well, still low on power but stronger that it was the last failed attempt at driving it. I made 3 trips around the block without stalling out. That was a big improvement. I decided to attempt to drive around the back roads to see if the stalling was really gone now. I drove 21 miles without issues, so I assume the 2 faulty injectors were the culprit for the stalling issue. The engine runs smooth now and does have more power than the last time I drove the car, but, the check engine light is still on and the timing is still retarded. When I returned home I checked for fault codes and found I now had two fault codes #33 and #43. I attempted to remove the codes. The #33 code when away but the #43 is persistently stubborn and won't go away. Until that check engine light turns off the timing cannot return to normal. I don't know if driving the car around will eventually turn this fault code off or not. I had already replaced the knock sensor and inspected the wiring at the sensor. The water temperature sensor has also been replaced as well as all the spark plugs and all the injectors. The car so far seems drivable again, but I'm at a loss of where to look next to clear the #43 fault code.

New thread has been added.

Ken, I can't access the two new threads I just created. Can you see them and if so, have you responded to them. I can only access this thread for some reason.