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The engine will crank but not start sometimes which means either no fuel no spark or no compression. I thought it was ignition coil, which was busted but not the main problem apparently. No clue what to look for or how to look for it because the electronic fuel injection is very complicated. Any help would be appreciated.
 

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When it doesn't start I'd pull a spark plug wire to check if you have spark. A commonish problem on these cars as they age are ignitors failing.
 

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When it doesn't start I'd pull a spark plug wire to check if you have spark. A commonish problem on these cars as they age are ignitors failing.
i checked the spark plugs and they seems to be fine. it turned on later once I pressed the gas all theway down which leads me to believe it’s either the maf sensor, air filter, fuel filter, fuel pump, or something else but I’m not sure.
 

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It's not the spark plug I'm referring to. Pull the wire and hold the metal clip inside very close, but not touching to a metal surface and see if there is an arc when the engine is cranking. If there is no arc you have no spark. If you do it rules out a whole branch of problems you have. The ignitor is what triggers the spark to occur. Most of the stuff you list rarely fail, can't cause a no start, or usually isn't intermittent.
 

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It's not the spark plug I'm referring to. Pull the wire and hold the metal clip inside very close, but not touching to a metal surface and see if there is an arc when the engine is cranking. If there is no arc you have no spark. If you do it rules out a whole branch of problems you have. The ignitor is what triggers the spark to occur. Most of the stuff you list rarely fail, can't cause a no start, or usually isn't intermittent.
Ok so it randomly started again but there is like a squeaking noise I wish I could upload the video so you can hear and see how much the car visibly vibrates. I checked all the wires coming out of the dizzy to the spark plugs and they all produced an arc.
 

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It starts and runs, so the ignition is working, but its vibrating like crazy. It could be as simple as a vacuum leak but the squeaking is leading me down another rabbit hole. We'll get to the squeaking in a moment. But always diagnose in the order of cheapest/simplest fix first. You've already checked for spark, that was #2. Go back to #1 and look for vacuum leaks. If there are no vacuum leaks, then its probably not firing on all cylinders and there could be a number of reasons. First order of business is to figure out which cylinder(s). While its running like crap, pull one lead at a time and reattach. If pulling a lead kills the car or makes it worse, that's a good thing, meaning that cylinder is firing. Whichever lead you pull that doesn't kill it or make it worse is the one(s) that aren't firing. Again, cheapest/simplest fix to most expensive, so on to #3. Visually check every inch of the spark plug wire(s) associated with the dead cylinder(s). Anything suspect, replace. If nothing obvious, check the ohms with a multimeter (sorry you'll have to look up the spec as I'm too old to memorize such things). If out of spec, replace and try again. Nothing? On to #4. Lets see if its jumped time. That could put a couple of cylinders just far enough out to not fire. Connect your timing light and check that its somewhere near 10 degrees. If its way off, make sure the dizzy is still bolted down and hasn't turned. If loose, reset and try again. Timing OK? On to #5. Let's see if the fuel injectors are firing. You can get a noid light and learn how to use it but shade tree, put your ear to a long screwdriver held on each injector while its running and listen for the click. Any injectors not clicking? Replace and try again. #6 would be to check for fuel pressure. You actually need a special banjo fitting on the Supra but low fuel pressure wouldn't cause a squeak and more likely the car wouldn't even start at all so lets move on to #7 & 8.

Nothing we've tried so far would characteristically make a squeaking sound but things that would make it lose compression could squeak. Hate to say it, but if the squeak is coming from the top of the motor, I've seen broken cam followers cause this on the 5m. You could run a compression test, but of course its pretty simple to take the cam covers off and visually inspect the cams and followers. If those are all fine, then #8 its also possible that the tensioner pulley has siezed and maybe made the exhaust cam jump time (we already checked and the dizzy, i.e intake cam is on time). Take the upper timing belt cover off and inspect for any teeth missing from the cam belt or if the outer part of the belt appears polished. Beyond that, you're into #9, the valves themselves and a compression test, but I'm not expecting to hear valves squeak.

There's a few other related electrical things that could be at issue given the intermittent nature of the failure, but those also don't usually squeak and we've rarely seen cause this set of symptoms, so probably best to go down the traditional diagnostic tree of spark, fuel and compression first and rule out the obvious before chasing the enigmatic. Good luck.
 

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Very comprehensive this is so helpful I will be running down this list tomorrow thank you so much
 
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