The unfixable mystery problem

[GettaRobo]

Well, today I picked up my supra from the shop it's been at. The mechanic has officially given up on the car. He can only think that there may be a bad connection in the wiring system, but he's not sure. I also bought a speed sensor off of www.rockauto.com , but it does not fit in my car. So now I'm stuck with a broken car and a speed sensor that does not fit. Luckily I can return it. I've been having a hell of a time trying to find a speed sensor for that car. I basically want to replace it before I try anything else with the car since it's the 'easiest' to get at. The part number is 89411-30090 and upon further investigation, apparently a 30091 would work as well... If anyone knows where I might be able to obtain this part, it would be greatly appreciated. Aside from that, it looks like I may have to take a peak at the throttle body.

P.S sorry for the long delay in updates... I was on holidays and was only able to steal a wireless highspeed connection a couple times

[GettaRobo]

For anyone interested, I have uploaded a couple videos on youtube. The first is of the car running fine up to 4000 RPM and then as soon as you try to floor it, the engine starts cutting out: http://www.youtube.com/watch?v=DfHrL3gNaJ0

The second is of the car cutting out and how it will not go much past 5k even with it floored. Notice that the speedometer is not rising very quickly: http://www.youtube.com/watch?v=9p67-hROA-k

I hope this helps in diagnosing the problem that I'm having.

[*Deadman*]

Could it be the box?

[GettaRobo]

Good suggestion, but I'm thinking if the engine won't even rev past 5200 RPM that it probably isn't it. I forgot to add that when you leave it floored for a bit you can begin to smell raw fuel when the windows are down.

[*Deadman*]

what about a leaky injecter or a crack in the manifold

Im just throwing out ideas see if anyone clicks

[btwilson86]

It sounds to me that the air entering the engine is not being metered properly. I haven't seen much discussion of the possibility of a bad mass air flow sensor in this thread. If the sensor is bad, or if the wiring has been reconnected improperly, your computer will not be receiving an accurate measure of air and will not add the proper mix of fuel, therefore resulting in a loss of power (stopping you from increasing your rpm's with various loads). Note that you will still be able to rev in neutral or park as there is virtually no load on the engine, thus requiring little power to rev.

I tried finding a pinout of a N/A mass air flow sensor, but have failed in the search. Colored wires should be the same on similar year supras, so you might be able to cross reference that way. I say swap your Canadian MAF for your CA one and see if that helps.

[GettaRobo]

So I took a look at the wiring, and this is what I found.

The camera wouldn't really focus properly, but the yellow wire is bare at the beginning of the connector in this pic :


In this one, it shows two brown wires spliced into one. I'm wondering if this might be the issue:


Let me know what you guys think. I may be able to pull off the harness from my other car to fix it. Also, the maf was bad on this car so I have one from the US now that I got off of ebay. Both run fine on my parts car.

[*Deadman*]

Yea that looks a little dodgy man if you really want to you could change the looms or take it down to an auto sparky and get them to have a look

[btwilson86]

Yeah, I would check the wiring on your parts car's MAF sensor plug. Wire colors will probably be the same, and if so I would cut the connector off of it and splice it onto the Supra you're trying to get running. I'm pretty sure those 2 wires shouldn't be spliced together, but I can't say for sure as I don't have a N/A that I can easily go check the wiring on...

Hopefully that's your problem though. Would like to see this thread end with "I got the car running" sometime soon...

[El_supracabra]

I had been having this prob since i bought my supra. I tried the tune-up (dist cap, rotor button, wires, plugs), changed the gear oil in the tranny and rear diff., tested the igntion coil/module, and changed the oxygen sensor.
Then, i blew a head gasket.
After rebuilding the engine (pressure tested the head/cleaned/crack tested block/milled/decked/bore/hone/new pistons/ground crank/re-bushed rods/new bearings/metal Headgasket/arp studs/ port & polish/ new clutch/ new headers/ replaced EVERY vacuum line on the ENTIRE engine/ fuel filter/ cleaned injectors/ cleaned fuel rail/ new air filter/ OHM tested fuel pump relay/ igniter/ coil/TPS/ and all 3 pick up coils)
dropped in the engine. SAME PROBLEM!!!!!!!!! W.T.F!?
Next is ECU. idk what else to do either. I like the idea of replacing the mass air flow sensor.