The ground to the valve cover was the one that I added today - it wasn’t there for some odd reason. I’ll definitely check the t-stat ground tomorrow.

The ect sensor is the two wire plug under the distributor, the wires like to fray with age and will short out causing the cel. The hard start is because the ect sensor works in the same fashion as a choke does for a carburetor, when the engine is cold it adds in up to 38% more fuel for cold starts and tapers off as it warms up. With the code on the ecu will run a default temp and cause issues with coolant temp corrections. I doubt it's actually the sensor, most times its frayed or broken wires on the plug that goes to it.

I did notice that the wires going to the connector were showing bare wire, so I actually did cut it and solder another connector on, as well as changing out the sensor itself, but I still had the code afterwards, along with the air intake temperature sensor code and the TPS code.

I mean, I don’t think I would have popped the motor, but I suppose it is a good practice to not go into much boost with a CEL. I know you say that I have actual mechanical problems, but I almost want to disagree to an extent. I had no CELs before doing what I did to resolve my hesitation problems in boost. I didn’t touch the ECT, AIT or the TPS, so I don’t understand how or why I’m getting codes 6, 7 and 10. I also replaced the AIT and ECT sensors as well, and the TPS is almost new as well. As dumb as it sounds (and I’ve never personally witnessed it), I’ve actually heard of tunes ‘going bad’ and the resolution is to reload the tune. Not sure if a ‘bad tune’ could cause a CEL or two as well. Just thinking out loud.

Chips don't rewrite themselves. People always want the solution of a tune going bad because it's easier to blame it on something else then taking a deeper look at the car. These are old cars with old wiring. A bad chip would throw complete limp mode not start random trouble codes for ect, ait and tps. I tune cars everyday for a living since 2010. Take a closer look st your wiring, make sure all the harness plugs are plugged in, check your t stat ground, if you have an ecu jumper harness unplug and plug it back in, look for loose pins in it and move it around. And like other dude said don't drive your car till the cels are gone and it's running like it should be

Oh my favorite tool, the multimeter - NOT. I hate wiring and electrical work the most. Looks like I may be at this for a little while. I’m gonna try to put a bigger chunk of time into this car today.

Oh please don’t tell me that lol. I’m already not looking forward to it!

Wiring is really quite simple once you understand it. Using a obd1 ecu pinout found on google you can be aware of what every wire on your ecu harness is for then do a continuity test from the ecu to the matching wire on the sensor plug. For the tps code, it's not uncommon to see People install the tps without lining up the moving arm that actually gives the variable voltage reading. So even when the throttle body moves the tps sensor sits still and shows no voltage change. To test the tps, plug a multimeter lead into the middle wire which should be read, with ignition on and the other lead to a ground you should get about .45-.49v at throttle closed and about 4.5v at wide open throttle. Test that first and report back what it's doing and we can go from there to see what's up.

Okay, so I resolved the issue. There was a point within the past couple days where I also replaced my clutch master and slave cylinders. While replacing the master cylinder, I noticed a lone wire, balled up in the corner that didn’t look like it went to anything, so I grabbed it and pulled it out. It was a wire that somebody had ran themselves - it was not a factory wire.

Anyways, there was no resistance when I pulled it out, and though one end of the wire had the rubber covering stripped off of it and the other end had some solder on it, it didn’t look nor feel like it was attached to anything - so I threw it out not thinking anything of it.

Upon my codes 6, 7 and 10, I decided to start by probing the TPS sensor to see what the closed throttle voltage was. I was getting 5 volts - yes, five volts and not point five volts. I tried loosening the TPS and turning it to see if I could change the voltage and it wouldn’t read anything other than five volts. I even tried a second multimeter with no luck. I left the TPS connector plugged in and completely removed the TPS and the voltage still read five. I knew something wasn’t right. Obviously the sensor was getting voltage, but not the right amount.

First thing I did at this point was check for continuity between the center connector wire and the ECU, which I did get continuity - great! Then I checked for continuity between wire ‘A’ of the connector (far left side wire) and chassis ground (since this is the ground wire for the connector) and I didn’t get anything.

Now I was starting to wonder if I had a ground issue. I then checked for ground continuity on the ECT sensor and the IAT sensor and neither of them had any continuity. At this point, I was now wondering if the 3 sensors didn’t share the same ground wire somewhere within the harness.

I took a shot at it and I ran my own ground from the TPS to the chassis (which if my theory of these 3 sensors sharing the same ground wire was correct, then the ground wire that I ran to the TPS should ground all 3 sensors). Then, I checked for continuity between chassis ground and each ground wire on the three sensors. All 3 sensors were now grounded!

My problem ended up being (my guess anyways) that the wire that I pulled out next to the clutch master cylinder was ran manually by the previous owner to ground these 3 sensors out.

Anyways, the car is running great now. I hope that maybe someday my experience can help somebody else out!

Congrats man! I bet this allowed you learn some valuable information about your car overall

It did, and as much as I normally hate wiring/electrical issues, I kind of actually enjoyed it this time.

I’m going to have to check that out! That makes complete sense.