Faulty Fuel Pump, Relay, Selonoid on trans?

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Junk

Junk

Joined
Dec 13, 2002
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buggerville nj
Need some help diagnosing this please.

Truck is 1997 USA Edition petrol 1FZ-FE (TRD supercharger added if that enters equation at all, even though I doubt it).

Truck is running great at first, then after about 20 minutes it has been having issues if at high RPM’s. If the truck is at 2200 RPM or below, there are no problems (although it has stalled twice in the last 2 days which is not normal). As soon as it gets to around 2250 RPM the transmission starts shifting down out of OD into 3rd, then back up and back and forth almost randomly.

I had the OBDII hooked up to it and there are no codes (including pending) and the highest the ATF got to was 99 degrees F and the highest the ECT got to was 198 degrees F. Once warm the truck is idling a tad rough also.

First though was transmission, but now thinking maybe fuel pump or fuel pump relay.

Any thoughts or suggestions? This happened while on the family vacation, but we are now back after a nervous ride home.
 
Junk said:
Need some help diagnosing this please.

Truck is 1997 USA Edition petrol 1FZ-FE (TRD supercharger added if that enters equation at all, even though I doubt it).

Truck is running great at first, then after about 20 minutes it has been having issues if at high RPM’s. If the truck is at 2200 RPM or below, there are no problems (although it has stalled twice in the last 2 days which is not normal). As soon as it gets to around 2250 RPM the transmission starts shifting down out of OD into 3rd, then back up and back and forth almost randomly.

I had the OBDII hooked up to it and there are no codes (including pending) and the highest the ATF got to was 99 degrees F and the highest the ECT got to was 198 degrees F. Once warm the truck is idling a tad rough also.

First though was transmission, but now thinking maybe fuel pump or fuel pump relay.

Any thoughts or suggestions? This happened while on the family vacation, but we are now back after a nervous ride home.
Click to expand...

Not a clue
One thought ...if it was a fuel related issue would it not do it in any gear above 2250?
 
Junk, you could bypass the fuel pump relay as Robbie mentioned in an earlier thread so pump is going full tilt. This will at least let you know if it's one of those.
Mike
 
Junk,

Clarify something for me.

99f tranny fluid - was this using an output from the stock sensor, etc or did you add a separate temp sender? The reason I ask is this is way cold and I'm suspicious the engine computer's mistakenly thinking the engine/tranny's cold and is keeping you in rich/cold start mode.

ECT temp - what is this? To me this stands for the Electronically Controlled Transmission - a button on my dash.

DougM
 
Junk, do you have more than one shift indicator light on?
 
IdahoDoug said:
Junk,

Clarify something for me.

99f tranny fluid - was this using an output from the stock sensor, etc or did you add a separate temp sender? The reason I ask is this is way cold and I'm suspicious the engine computer's mistakenly thinking the engine/tranny's cold and is keeping you in rich/cold start mode.

ECT temp - what is this? To me this stands for the Electronically Controlled Transmission - a button on my dash.

DougM
Click to expand...
Doug

I think he means Engine Coolant Temp. Which oughtta be 198 and would be what the ECU is looking at for cold/hot fuel mixture. My OBD II system does not have a sensor for trans temp, but it is just a 95 partly OBDII system.

99F does seem awful cold for trans temp

I like fuel pump relay or fuel filter myself. You could also have gotten bad gas, expecially on a road trip during winter/summer fuel change-over times. What does your scan tool read for O2 during the times it's happening? Is it starving for fuel?

Perhaps a loose hose from the MAF to the t-body? Maybe the data is showing a bunch of engine load when it's really isn't.

Welcome back - beeeyiotch. You're gone for a couple fo days and everybody over in Chat starts complaining. :flipoff2:
 
It sounds like a fuel related problem but I would think that an OBDll system would show a fuel related problem on a scanner? Also, if it is a fuel pump or relay or even a clogged filter, one would think that there would be detonation involved especially under a boost condition? It still sounds like a fuel related problem but a fuel pressure gauge at the fuel rail will clear up any doubt.
The fact that the tranny is up/down shifting leads also to something electrical in the tranny loop, since they are electronically controlled by TPS , VSS, and MAP.
I am suprised that the OBD scanner is not picking up a code if the engine is dying and running rough at idle.
 
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<<<"You could also have gotten bad gas">>>



:eek:


Jeeze Todd..........Junk with BAD GAS? How is that possible? :flipoff2:
 
IdahoDoug - ECT - as Gumby mentions, engine coolant temp and yes it got up to 198 deg F and no more. 99 def F for ATF was from OBDII streaming data using the OBDII reader.

Jesterb - nope. Only the D light.

Gumby - thanks, will check hoses. Chat, LOL, only cause of momma :D For the 02, don't know if it's starving or not. What would be a typical reading or what would I look for? I know that one of the sensors is closed and one is open; but it's supposed to be that way or I'm looking at something else.

Wagg - yeah, I am surprised by no code. I thought any stall would create one, but this happened to a buds truck when his stalled - it threw no code either.

PHil - I don't know. What other info do you need? That's all the relevant data I know of for now.

Landtank - I'll check the wiring harness thanks. Hmm, I do remember the EGR hose falling apart a few weeks ago and I replaced it with fuel line, but that was like 2-3k miles ago. WIll check though.

Cdan - only time I get bad gas is when I talk to you on the phone :flipoff2:
 
You mean I can search? Gee, I NEVER THOUGHT OF THAT :flipoff2:

I know it's an issue with the lowly 3fe and the EFI relay. I also know it can be an issue with the sc, but it's like NASA wrapped (which could be an issue :flipoff2:, but I suppose with the no exhaust run I had a month ago it could have some issues).
 
This is an EASY diagnosis...........:D


Loose nut behind the steering wheel...:flipoff2:
 
This is anecdotal from a decade ago, but I seem to recall that the Toyota OD circuit used tranny fluid temps as an input. And a reading of 99 is suspiciously low, and also being of the "99999" variety leads me to believe it's not correct.

Tell me about the stalls. What speed, etc. I'm wondering if you're actually seeing RPM changes because the torque converter's locking/unlocking rather than O/D. You may be able to see the RPM difference by playing with the O/D button and seeing if the RPM drop is the same as the random one. If you tell me it stalled leaving a dead stop, then the torque converter or a clutch may be an issue. I'm assuming you've checked your tranny oil level? This because if a the fluid' s low enough that its sensor is not immersed in oil it will show a false low reading.

Or it could be a fuel issue as others are working. The lack of a code is strange.

DougM
 
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Others have had issues with that harness and EVERYTHING passes through it. When I mean everything I mean everything. All sensors engine, O2 and transmission. I thought some had problems not evident with a visual but I can't be sure.
 
The following relates to my 96 LX not sure if/how other years differ

This does not sound like the same symptoms I had with the fuel pump relay, when the problem kicked in there was no fuel, as in will not even try to start or if already running will die

The fuel pump relay controls 2 settings of the fuel pump,

High voltage, just strait battery voltage to pump
Low voltage, battery voltage is routed through the fuel pump resister to lower it output,

Mine was bad on the high side witch is used for higher throttle openings and starting, if I could get it started I could drive around just fine as long as I drove like grandma, there are two other relays in the path to the fuel pump, the EFI MAIN
RELAY and the circuit opening relay, they were the same part # and fairly inexpensive at the local Toyota dealer, I bought one replaced the EfI, no change moved the old EFI to the circuit opening spot again no change but I now have a spare for either

The Fuel pump relay was $98 and not in stock at my local dealer (not enough time to go to Dan), so I took it apart and cleaned the contact with contact cleaner and all is well

My fuel pump problems never caused a code, as far as the computer knew everything has a OK :/

I would change the tranny fluid and check the adjustment of the kick down cable, try the low hanging fruit first, I cant help with much beyond that with a transmission except I have heard the Toyota solenoids commonly get plugged
 
Thanks everyone.

IdahoDoug - actually, both stalls were leaving the driveway. Not actually when pulling out, but when slowing down to the end of the driveway to check for traffic prior to pulling out. It stalled twice, out of like the 30 times I did this though, but it rarely ever (as in I don't remember the last time it happened). So I was only going like 10mph slowing down to 0 when it happened.

Landtank - thanks. Looked at the harness today. Everything APPEARS to be in decent condition, but as you say you can't tell by looking. It is very heavily wrapped in real high temp stuff though.

RavenTai - thanks, but I don't even know that the kickdown cable looks like. :whoops:
 
Kick down cable has a more proper name that is used around here, I cant remember what it is now :doh: , anyway there are 3 cables coming off the throttle body, one wraps around the front of the motor and disappears into the firewall on the USDS, that is the skinny pedal cable, the second runs along the rubber air duct to the cruise control unit, and it is for cruise, the third runs above the exhaust and disappears under the USPS firewall that is the kick down cable,


To check the adjustment look at the throttle body end of it where the inner cable comes out of the outer sheath there is a metal bead crimped on, this bead should be covered by but flush with the rubber end of the sheath with the throttle at idle
 
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