The unfixable mystery problem

GettaRobo · 07-16-2009, 11:21 PM

So I talked to the mechanic today. Timing belt is fine, cams are properly aligned. Honestly, we are completely out of ideas. Since combustion requires three things: air, spark, and fuel, it's either not getting one of these things or perhaps it's something else. I know it's getting air, I'm reasonably sure it's getting spark (new wires, plugs, distributor has been checked, as has the coil wire,) and there is plenty of fuel pressure. Is there any way it is remotely possible that the tranny is dying on me? I mean the oil doesn't smell burnt or look brown and there are no metal shavings in it... The only tranny error code I'm getting is the speed sensor 2 error. So unless someone else has a revolutionary idea or something, I think I'm SOL.

carl johansson · 07-18-2009, 06:07 AM

Have you looked at the throttle cable? have someone sit in the car and floor it = while you watch the cable - maybe the cam lobe broke off or something stupid like that - so it's going back low throttle -

compare that to watching when you are at 3/4 throttle and it revs to redline.

I assume you took the fuel pressure after the fuel filter right?

It almost sounds like it's getting to much fuel at full throttle - did someone change the injector sizes? and isn't there an adjustable fuel pressure regulator? To much fuel at full throttle could be choking it off - while 3/4 is allowing enough air! It used to be a fairly common problem in carbed cars!

Just throwing out ideas - I don't know!

Carl Johansson

GettaRobo · 07-21-2009, 09:59 PM

Sorry for the long delay, was out of town and only had access to a dialup connection... Anyway, I don't think it's the throttle cable since it'll redline in neutral and park when you floor it. As for the fuel pressure, I wasn't the one checking it, so I don't know but I'll find out. I don't believe that anyone changed the injector sizes, but that could be a possibility. It was running rich at one point before I changed the AFM. The car is initially from the Los Angeles area, and now the car is definitely at a higher elevation here in Saskatoon, but you'd think that the other car that I have would run the same as this one if that were the case unless there's some elevation tuning differences that I don't know about. Apparently the mechanic had no clue about the speed sensor problem until I told him about it today... so basically he's going to see what all it controls and if it's causing the ECU to go in to 'limp mode.' It's a long shot, but I'll try some of the stuff mentioned here as well as the speed sensor issue and see what happens.

jcastro · 07-22-2009, 09:11 PM

try doing a smog check and ask to check ur vacume lines if it dosent pass the smog ull at lest have a better idea of wut it is and im pretty sure thell tell u whats wrong

86.5supra · 07-23-2009, 03:47 AM

i had the same problem after i had my 7mgte rebuilt. the shop couldnt figure it out so they took the motor out tore it apart and put it back in the car. It turned out to be a bad throttle body and mass air. hope this helps

GettaRobo · 08-05-2009, 07:31 AM

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 · 08-16-2009, 02:41 AM

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.

07-23-2009, 03:47 AM	#5
86.5supra 3" Exhaust Join Date: Jun 2009 Location: ny Posts: 83	mystery problem i had the same problem after i had my 7mgte rebuilt. the shop couldnt figure it out so they took the motor out tore it apart and put it back in the car. It turned out to be a bad throttle body and mass air. hope this helps

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07-16-2009, 11:21 PM	#1
GettaRobo 3" Exhaust Join Date: Apr 2009 Location: Saskatoon, SK Posts: 65	So I talked to the mechanic today. Timing belt is fine, cams are properly aligned. Honestly, we are completely out of ideas. Since combustion requires three things: air, spark, and fuel, it's either not getting one of these things or perhaps it's something else. I know it's getting air, I'm reasonably sure it's getting spark (new wires, plugs, distributor has been checked, as has the coil wire,) and there is plenty of fuel pressure. Is there any way it is remotely possible that the tranny is dying on me? I mean the oil doesn't smell burnt or look brown and there are no metal shavings in it... The only tranny error code I'm getting is the speed sensor 2 error. So unless someone else has a revolutionary idea or something, I think I'm SOL.

07-18-2009, 06:07 AM	#2
carl johansson 3" Exhaust Join Date: Nov 2007 Location: Auberry, California Posts: 141	Have you looked at the throttle cable? have someone sit in the car and floor it = while you watch the cable - maybe the cam lobe broke off or something stupid like that - so it's going back low throttle - compare that to watching when you are at 3/4 throttle and it revs to redline. I assume you took the fuel pressure after the fuel filter right? It almost sounds like it's getting to much fuel at full throttle - did someone change the injector sizes? and isn't there an adjustable fuel pressure regulator? To much fuel at full throttle could be choking it off - while 3/4 is allowing enough air! It used to be a fairly common problem in carbed cars! Just throwing out ideas - I don't know! Carl Johansson

07-21-2009, 09:59 PM	#3
GettaRobo 3" Exhaust Join Date: Apr 2009 Location: Saskatoon, SK Posts: 65	Sorry for the long delay, was out of town and only had access to a dialup connection... Anyway, I don't think it's the throttle cable since it'll redline in neutral and park when you floor it. As for the fuel pressure, I wasn't the one checking it, so I don't know but I'll find out. I don't believe that anyone changed the injector sizes, but that could be a possibility. It was running rich at one point before I changed the AFM. The car is initially from the Los Angeles area, and now the car is definitely at a higher elevation here in Saskatoon, but you'd think that the other car that I have would run the same as this one if that were the case unless there's some elevation tuning differences that I don't know about. Apparently the mechanic had no clue about the speed sensor problem until I told him about it today... so basically he's going to see what all it controls and if it's causing the ECU to go in to 'limp mode.' It's a long shot, but I'll try some of the stuff mentioned here as well as the speed sensor issue and see what happens.

07-22-2009, 09:11 PM	#4
jcastro 3" Exhaust Join Date: Mar 2009 Location: El Centro Posts: 113	try doing a smog check and ask to check ur vacume lines if it dosent pass the smog ull at lest have a better idea of wut it is and im pretty sure thell tell u whats wrong

08-05-2009, 07:31 AM	#6
GettaRobo 3" Exhaust Join Date: Apr 2009 Location: Saskatoon, SK Posts: 65	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

08-16-2009, 02:41 AM	#7
GettaRobo 3" Exhaust Join Date: Apr 2009 Location: Saskatoon, SK Posts: 65	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.