Yep, these cars will suck you dry and keep asking for more. Why do you think they are so rare? It's because people just get fed up with them and junk 'em. It takes alot of patience and knowledge to put up with a MK3 supra. You must have a passion for them, or its just not going to work out, kinda like a relationship :)

You should test the resistance of the MAF. Take the MAF off the intake piping. Now, looking at the terminals with the MAF upright (rectangular air box side to the left, circular turbo side to the right) the terminals are labeled from left to right E1, Vc, Ks, THA, E2. Heres the chart from the TSRM:

Ks -> E1 should have infinite resistance.
E1 -> Ks should be between 5-10K ohms.
Vc -> E1 should be between 10-15K ohms.
E1 -> Vc should be between 5-10K ohms.
THA -> E2 is ambient temperature dependant.
At 32F resistance should be 4-7K ohms.
At 68F resistance should be 2-3K ohms.
At 104F resistance should be .9-1.3K ohms.
Basically the resistance should fall as the temperature increases.

Now gut that cat or buy a test pipe and see what happens. And I was just busting your balls about the rod knock, it really sounds like preignition to me, have you been running 93 octane or 87?

Thanks man! Sounds like you really know your stuff when it comes to these cars.

Ill test it this afternoon and see whats up.

Its got 87 in it. Also Im sure the old gas from it sitting up doenst help at all. I put some 105 octane booster in it to try and help it some.

Lol, Im still going to start building the other that way im not in a rush. It does sound like some knock or somehting is loose, doesnt sound like a rod bearing.

Worked on the supra for a bit this afternoon and found that the TB is sucking air. Its right between the intake and the TB. I pulled it off and plan on putting a new gasket tommorrow. If only this is going to be my problem.

I just took it for granted that you didn't have any vacuum leaks.

A vacuum leak after the MAF will cause a check engine light (for the MAF) and will also cause a lean condition which will cause that pinging sound you hear.

I think the TB gasket will fix your problem.

I did to until I could hear a small hiss under the hood. So I broke out the starting fluid and started spraying around where everywhere something meets up. And sure enough, I spray it around the TB and the car tries to die. So bingo, found a vacuum leak. I should know this afternoon whether or not it does fix it. Right now it seems to start and idle fine, a little hesitant when you give it gas but will not rev past 2500rpm. Its like its hitting the fuel cutoff. But I wonder why it would run fine for a whole day then i wash under the hood and it all of a sudden gets a vacuum leak. Its crazy!

I also took the cat off and gutted it. So maybe that will help a bit. I also plan on swapping out the fuel filter today to.

Ok fixed the TB from leaking and changed out the fuel filter and its still doing the same thing. It revs, spits sputters, backfires and want go anywhere. Ive checked every plug and connector on the car for moisture and all are clean and dry. Timing is right at 11-12* idling. Ive pulled the timing cover to verify the cam sprockets and crank line up with each other and they do. the crank mark will be on 0 and both cam sprocket marks are with the mark on the backing plate. Still throwing the 31 code for the maf but thats it. All the rest are gone. Im at a dead end with this car. I dont know what else to try anyboy have and suggestion?

IT FINALLY RUNS! Replaced the igniter with one off my parts car and bam, runs like a champ. Still got the MAF code and its a little low on power but its running is the main thing. About to do a compression check on all cylinders and seewhere that stands. Also have some rod knock. Thought maybe it was something loose but its defiantly rod knock. Im going to track down a MAF and see if I can rid of that code and then Ill start form there. Going to pull the motor from the donor car this weekend and start getting it ready to be swapped when this one dies. I did shim the waste gate .022 so the boost was right at 7psi. I dont guess ill up the boost until I get the new motor ready. But thankfully she's running.

RIGHT ON MAN.

I have been keeping up with both threads, but haven't had anything helpfull to add. So call it learning.

Glad it worked out.