The unfixable mystery problem - Page 2

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

07-23-2009, 03:47 AM	#4
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

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
ABS Problem?	rasclaat_98	MKIII Supra	6	12-13-2010 09:53 PM
speed sensor problem	nadircicek	Non-Generation Specific Questions	8	10-09-2009 05:58 PM
another heater problem	nicnet	MKIII Supra	16	12-05-2007 10:18 PM
found the problem	brs86supra	MKIII Supra	0	05-02-2006 03:42 PM
Boost Problem, I Guess	nonstop213	MKIII Supra	0	02-23-2006 07:32 PM

07-18-2009, 06:07 AM	#1
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	#2
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	#3
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