An interesting problem

GettaRobo · 06-06-2009, 02:16 AM

Hi everyone, so I recently got my timing corrected from 30 degrees to 10 degrees where it should be, and the maf is no longer thinking that the ambient temperature is -40 C/F outside. Here lies the problem. Anytime that I try to take the car past 4000 RPM, it seems that the fuel is being cut. The engine will rev, and the car jerks. In addition to this, when I try to get my car past 60 mph, it's almost like the engine is misfiring or something, it seems to stutter and jerk a bit. This part of the problem never happened before the timing and maf were corrected/replaced. I have new plugs and wires on the car and no error codes other than code 61 (speed sensor #2 on the tranny). It was suggested to me that I remove the sensor completely and try that. Also suggested to me were to reset the ECU and since my fuel tank was almost empty, to fill it and see if it might possibly be a fuel pressure problem. I have filled the tank since then and have experienced the same problems... I was wondering if anyone here would have some pointers or suggestions in addition to this. Thanks!

P.S. Car is a n/a 88 supra with an auto tranny

Edit: This is also a Californian car. It has a few extra sensors for emissions control and whatever. It was suggested to me by a friend that there may be a rev limiter on it. Also, for whatever reason it is now misfiring like crazy... Something tells me that I bought a lemon back in January.

GettaRobo · 06-06-2009, 10:15 PM

So here's an update: Filled the tank, still does the same thing. Pulled 3 of the easy to get to spark plugs, one had carbon deposits on it. Put it back it, and doesn't APPEAR to be misfiring anymore. Also unplugged the ECU for the night and plugged it back in today. Now the car won't shift out of second... Speed sensor? probably. Bad ECU? possibly. I'll try to swap it out with another one later today.

Edit: so I lifted the hood again today and found a disconnected TPS connector. Plugged it in and it worked like a charm. The only problem I'm still having is the speed sensor that I can't do anything about yet, and the 4000 RPM bogging down/fuel cut problem. Could this be a fuel pump problem?

06-06-2009, 02:16 AM	#1
GettaRobo 3" Exhaust Join Date: Apr 2009 Location: Saskatoon, SK Posts: 65	An interesting problem Hi everyone, so I recently got my timing corrected from 30 degrees to 10 degrees where it should be, and the maf is no longer thinking that the ambient temperature is -40 C/F outside. Here lies the problem. Anytime that I try to take the car past 4000 RPM, it seems that the fuel is being cut. The engine will rev, and the car jerks. In addition to this, when I try to get my car past 60 mph, it's almost like the engine is misfiring or something, it seems to stutter and jerk a bit. This part of the problem never happened before the timing and maf were corrected/replaced. I have new plugs and wires on the car and no error codes other than code 61 (speed sensor #2 on the tranny). It was suggested to me that I remove the sensor completely and try that. Also suggested to me were to reset the ECU and since my fuel tank was almost empty, to fill it and see if it might possibly be a fuel pressure problem. I have filled the tank since then and have experienced the same problems... I was wondering if anyone here would have some pointers or suggestions in addition to this. Thanks! P.S. Car is a n/a 88 supra with an auto tranny Edit: This is also a Californian car. It has a few extra sensors for emissions control and whatever. It was suggested to me by a friend that there may be a rev limiter on it. Also, for whatever reason it is now misfiring like crazy... Something tells me that I bought a lemon back in January. Last edited by GettaRobo; 06-06-2009 at 04:56 PM.

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
Interesting power loss problem!	stssa	MKIII Supra	4	01-13-2009 04:54 PM
another heater problem	nicnet	MKIII Supra	16	12-05-2007 10:18 PM
Boost Problem, I Guess	nonstop213	MKIII Supra	0	02-23-2006 07:32 PM

06-06-2009, 10:15 PM	#2
GettaRobo 3" Exhaust Join Date: Apr 2009 Location: Saskatoon, SK Posts: 65	So here's an update: Filled the tank, still does the same thing. Pulled 3 of the easy to get to spark plugs, one had carbon deposits on it. Put it back it, and doesn't APPEAR to be misfiring anymore. Also unplugged the ECU for the night and plugged it back in today. Now the car won't shift out of second... Speed sensor? probably. Bad ECU? possibly. I'll try to swap it out with another one later today. Edit: so I lifted the hood again today and found a disconnected TPS connector. Plugged it in and it worked like a charm. The only problem I'm still having is the speed sensor that I can't do anything about yet, and the 4000 RPM bogging down/fuel cut problem. Could this be a fuel pump problem? Last edited by GettaRobo; 06-08-2009 at 12:48 AM.