Faulty Fuel Pump, Relay, Selonoid on trans?

[Junk]

One more douse of info: this does not happen during rapid acceleration. Drove it out on the Freeway and during acceleration to 60 - no spontaneous shifting or anything out of the ordinary. Same goes for back roads. Seems to only happen at highway speeds although keeping 1/2 eye on OBDII MPH vs Speedo - everthing checks ok as does OBDII RPM vs guage RPM.

I hate this beater.

 

[sjcruiser]

This is an EASY diagnosis...........


Loose nuts behind the steering wheel...

I thought that for most (if not all) of us it would be uncomfortable if they're being tight (or too tight)

 

[Waggoner5]

That would seem to rule out a few things in my opinion. The TV cable that controls the shift habits of the tranny, the fuel filter, and or fuel pump. Since the truck seems to run well and shift well at WOT, this leaves a couple of more things. Wiring has intermittant short, TPS has a corroded spot in it, or MAP readings inconsistant. All three of these could cause your symptoms, but I still don't understand the ECU not throwing a code??? Can you actually see the 5 volt reference signals from the sensors on your scanner? If so watch the TPS voltage as you slowly tip into the throttle. See if at idle it is around .90 volts and climbs to around 5 volts at WOT. Check also that the MAP sensor is both correct at your current Bar. press. and the voltage changes as you throttle up.
Gary

 

[Gumby]

Check that TPS movement with the key on engine off, Junky. should be nice and smooth from idle to WFO with no glitches.

I'm not sold that it isn't the TV cable adjustment.

 

[landtank]

I say we bolt that SC on my truck and we give it 6 months or so for a full shakedown to be sure to rule that out.

 

[robbie]

I would second the TPS and look closely at it, I would also look at the wires just above the starter and see if any are getting wet with coolant from the little heater hose or it 90 degree cusion on top. Some time the high temp sheathing looks ok until you look real close. Was this sheating setting against the EGR pipe, if so it may not show externally any real marks except a small flat spot. So If it was laying against the pipe I would round up some of the special heat tape from a speed shop and have it handy when you go in to check the wires underneath. I have seen where the wire loom with this tape to prevent heat destruction has actually masked melted wires under neath. This usually holds true if it has been resting on the pipe.
If you can not see the voltage risisng on the computer then take a volt ohm meter and un plug the plug to the TPS and measure the values according to the FSM ( I think you can read toyota speak?), also a quick look above the starter to make sure no liquids are hitting these conections or you have some rubbing wires in this area. Wish I was closer to help with the pile of junk. later robbie

 

[Junk]

Wish I was closer to help with the pile of junk. later robbie

That makes two of us. Thanks for the help. Hope to spend some more quality time with it tomorrow and Sat. Enjoy the long weekend!

 

[landtoy80]

1997 USA Edition
I hope they didn't make too many like yours

You say the motor has been replaced more than once right?
Maybe the harness could be worn from all that messing with.

Have you tried a "flight data recorder" from a repair shop?
You hook it up to the OBDII and push a button when you have a problem. It recordes everything motor and tranny was doing for 60 sec before and after you push the button.
This might help solve your EGR problem too.

With all the problem you have (motors, egr, tranny or fuel pump) maybe you have a problem with your computer.
With all the hard wheeling you do your 80, you may connectors are corroded.

 

[Beowulf]

Kurt,

Has the nice doctor been by to see you today? I think it's time for you to take a little nap and get some rest. You don't want to pop out those lobotomy stitches now do you. Say good night now and you can play with your little friends tomorrow when you're lucid.



-B-