Engine shutting off during long trips. (1 Viewer)

[kklaus121]

All accounts can add a signture line in mud. You should be able to see my signture line below.

06-07 have a weak fuel pump. Typically they show themselves as they get hot. This happens mostly on hot or warm days, after running in high RPM for a few minutes. Like when pulling up a mountain pass. Then as we let off gas pedal to descent mtn pass, engine dies from fuel starvation (lean fuel bk 1 & 2). What happens is fuel pump heats up in high speed mod, building up resistance in motor and possible it's circuit.. Then as we let of gas, fuel pump drops back to low speed mod. The increase resistance due to heat, reduces fuel pressure/flow. Fuel pump fails to produce enough follow/pressure.

Stalling not just in High, Hot, & Heavy

2006 LC100. Twice in the last month the 100 has stalled and won't restart. Yesterday during highway driving and though it is warm out in CO in July, certainly not desert temperatures. Had a more classic feel of vapor lock (I know this is not necessarily a situation here). Vented the gas cap...

forum.ih8mud.com

That said:

I don't see ethanol free gas making much difference, to fuel pump. Other than return (EVAP) fuel heating around engine, heating fuel in tank. This could raise fuel pump temp a little.

Blocking fuel pump resistor heat sink, could affect resistance I suppose. Condition starting just afterwards, certainly points to a relationship. Getting it stall "on demand", then remove blockage (aftermarket air) and try to repeat. Would be helpful diagnostic tool..

Your engine may be running hot:

This could be from engine & it's coolant system in need of service. A starting point even before removing aftermarket air. Is to monitor engine cool temp (ECT), fuel trims long & short term (FT), RPM, MPH, IAT (intake air temp) and CAT temps. This is done by hooking into tech stream and motioning actual data as you drive a recreate stall.


Fuel boiling:
There is another issue we see on all years. "fuel boiling". In most I find, engine is running hot. This is very often engine & coolant system issues, that need correcting. Once corrected, most 98-02 (before Charcoal canister CC moved to rear) stall issue goes away for the most part. But in the 03-07 (CC moved to rear), these tend to keep having fuel boiling issues.

Gas tank building excessive pressure & fuel smell. Dangerous for sure! Why does this happen?

DANGEROUS GAS PRESSURE BUILD UP IN GAS TANK! Why? What's going on? How can we fix this? Edited 12/29/23: It is a unban myth, all Land Cruisers boil fuel. They do not! Edited 7/4/20: What I found in every case of "fuel boiling" I've worked on. Was, engine overheating or running hot. :hmm: That...

forum.ih8mud.com

Some think all 100 series boil fuel. This is simple not so. Many stock and built rig, don't. None, did the day they came from the factory. So something happens along the way

If you like stop by and we can take a test drive. I can hook into tech stream and monitor. I'll also look over and see if I can spot and signs that point to over heating issues and or fuel boiling.

Just PM (private message) your phone number and or email. I'm in Greenwood near Trader Joe's . We can set a time for you to stop by.

I have suffered from fuel pump failure on my '06 as well. I have a fuel pressure gauge installed so I have been able to monitor fuel pressure since the fuel pump was replaced about 7 years ago now. Two summers ago I saw fuel pressure dropping to 39-40lbs so I figured it was time to replace again. I ordered one and have it ready to install when needed. However, I switched to non-ethanol fuel and run this solely during the summer months here in Colorado.

I have never seen low fuel pressure during the winter months at all.

What I have witnessed is the use on non-ethanol fuel during the summer has increased the fuel pressure consistently to 41-42lbs. For two summers this has been the case. I do believe the current fuel pump is "weaker" than it was brand new as pressures then were 42+ but it is still within specification and no stalling. This is merely my anecdotal information. There certainly may be other factors at play here, but running non-ethanol fuel in the summer has kept my '06 running. I plan to run non-ethanol fuel again this summer and continue my experiment.

 

[RoySan]

Hi :

I'm so glad I found this forum!!

April 2016
I have my first FP failure after being pulled my trailer (2,000lbs) for about 2hrs, low speed and using in some moments LOW gear
Start smelling gas vapors, then stalling. After let it rest for about 40min, problem was gone.

Nov 2018
Going in the highway, start stalling again, we blamed the fuel, we suspected fuel was dirty because we found others cars with same problem in the area.

Jan 2019
Again in highway start stalling again, as soon as I win some speed start working fine.

Feb 2019
Changed the FP with and original Toyota spare part. Problem fixed 100%

April 2022
After driving like 2 hours in highway, then climbing for about 30min at low speed, we got to a flat road, with a lot of traffic...
I turned it off for a couple of minutes later could not started, if started you can see the RPM very unstable without any power.
I had the same issue a couple of time since then... same situation, working ok, then turn it off for some minutes, then stalling..

I will change the FP, I'm ordering Denso 950-0210, just found the recommendation in the forum.. Thank you!
I believe the current FP just lasted 3 years when the original lasted for 10 years due a poor performance in the electric or cooler system..
I will check all the recommendations found in this thread..

Question, Is the "BlueDriver Bluetooth Pro OBDII " the best option?
I want to see the current data before do any change, so I can compare later..

Thank you!

 

[Calvinswartz]

Hi :

I'm so glad I found this forum!!

April 2016
I have my first FP failure after being pulled my trailer (2,000lbs) for about 2hrs, low speed and using in some moments LOW gear
Start smelling gas vapors, then stalling. After let it rest for about 40min, problem was gone.

Nov 2018
Going in the highway, start stalling again, we blamed the fuel, we suspected fuel was dirty because we found others cars with same problem in the area.

Jan 2019
Again in highway start stalling again, as soon as I win some speed start working fine.

Feb 2019
Changed the FP with and original Toyota spare part. Problem fixed 100%

April 2022
After driving like 2 hours in highway, then climbing for about 30min at low speed, we got to a flat road, with a lot of traffic...
I turned it off for a couple of minutes later could not started, if started you can see the RPM very unstable without any power.
I had the same issue a couple of time since then... same situation, working ok, then turn it off for some minutes, then stalling..

I will change the FP, I'm ordering Denso 950-0210, just found the recommendation in the forum.. Thank you!
I believe the current FP just lasted 3 years when the original lasted for 10 years due a poor performance in the electric or cooler system..
I will check all the recommendations found in this thread..

Question, Is the "BlueDriver Bluetooth Pro OBDII " the best option?
I want to see the current data before do any change, so I can compare later..

Thank you!

View attachment 2997002

View attachment 2997021

check this thread out.https://forum.ih8mud.com/threads/stalling-not-just-in-high-hot-heavy.1069542/

@2001LC and I have done lots of thinking and moving the fuel pump resistor to inside the air box fixed it for me.

 

[2001LC]

Hi :

I'm so glad I found this forum!!

April 2016
I have my first FP failure after being pulled my trailer (2,000lbs) for about 2hrs, low speed and using in some moments LOW gear
Start smelling gas vapors, then stalling. After let it rest for about 40min, problem was gone.

Nov 2018
Going in the highway, start stalling again, we blamed the fuel, we suspected fuel was dirty because we found others cars with same problem in the area.

Jan 2019
Again in highway start stalling again, as soon as I win some speed start working fine.

Feb 2019
Changed the FP with and original Toyota spare part. Problem fixed 100%

April 2022
After driving like 2 hours in highway, then climbing for about 30min at low speed, we got to a flat road, with a lot of traffic...
I turned it off for a couple of minutes later could not started, if started you can see the RPM very unstable without any power.
I had the same issue a couple of time since then... same situation, working ok, then turn it off for some minutes, then stalling..

I will change the FP, I'm ordering Denso 950-0210, just found the recommendation in the forum.. Thank you!
I believe the current FP just lasted 3 years when the original lasted for 10 years due a poor performance in the electric or cooler system..
I will check all the recommendations found in this thread..

Question, Is the "BlueDriver Bluetooth Pro OBDII " the best option?
I want to see the current data before do any change, so I can compare later..

Thank you!

View attachment 2997002

View attachment 2997021

check this thread out.https://forum.ih8mud.com/threads/stalling-not-just-in-high-hot-heavy.1069542/

@2001LC and I have done lots of thinking and moving the fuel pump resistor to inside the air box fixed it for me.

@Calvinswartz made a very keen observation, after installing air compressor. Which mounted next to heat sink of the fuel pump resistor. Wherein he began have stall issues, acting very much like the 06-07 failing fuel pump. He's not yet tested his mod (moving resistor into air box), in summer heat. But to-date, he's reported that in near the same OAT and sun, as it was stalling. It is no longer is stalling.

While not common in the 100 series to see these resistors fail. Seems he's onto something with build rigs having extra aftermarket gear blocking resistor heat sink. In which resistor can't dissipate heat as well as it should.

 

[RoySan]

check this thread out.https://forum.ih8mud.com/threads/stalling-not-just-in-high-hot-heavy.1069542/

@2001LC and I have done lots of thinking and moving the fuel pump resistor to inside the air box fixed it for me.

Thank you... I'm checking it

 

[Escape Artist]

I had similar symptoms, recently upgraded my alternator ... Yesterday when I went to the store and I came back outside the cruiser wouldn't start. It was like it was vapor locking! I was wondering if this could somehow be tied to the alternator maybe it was pushing too much juice to the fuel pump and cause it to get weird but after some heavy reading in the depths of this forum - I discovered it was an air pocket in my coolant.

The air pocket was there because the radiator came out to get the alternator swapped ... I must confess I cheated and had a shop do it. Regardless they didn't turn on the rear heater when they were trying to make sure there was no air in the coolant system and that air bubble made the back of the motor quite hot, caused sort of a chain reaction I would guess. The cats or running hot enough I think to boil that fuel. I only drove it for about 20 minutes from the shop that swap the alternator to the store.

I have since burped the big girl and all is well. I remember the transfer case shifter was so hot I couldn't touch it ... I never would have thought it would have been some air in the coolant system.

 

[Calvinswartz]

I had similar symptoms, recently upgraded my alternator ... Yesterday when I went to the store and I came back outside the cruiser wouldn't start. It was like it was vapor locking! I was wondering if this could somehow be tied to the alternator maybe it was pushing too much juice to the fuel pump and cause it to get weird but after some heavy reading in the depths of this forum - I discovered it was an air pocket in my coolant.

The air pocket was there because the radiator came out to get the alternator swapped ... I must confess I cheated and had a shop do it. Regardless they didn't turn on the rear heater when they were trying to make sure there was no air in the coolant system and that air bubble made the back of the motor quite hot, caused sort of a chain reaction I would guess. The cats or running hot enough I think to boil that fuel. I only drove it for about 20 minutes from the shop that swap the alternator to the store.

I have since burped the big girl and all is well. I remember the transfer case shifter was so hot I couldn't touch it ... I never would have thought it would have been some air in the coolant system.

great job working through that, with my 07 at least i found that the 4 degrees fahrenheit engine temprature difference of running on ethanol free gas made the difference of a stall or not. for being a toyota these 2uz-fe’s sure are sensitive.

 

[lehiguy]

Buying a new 4Runner cured this problem once and for all.

 

[bozncsurf]

Buying a new 4Runner cured this problem once and for all.

I LOVED your cypress green LX! But I hear ya - same old problems on old trucks eventually gets OLD

Glad to hear you’re still in a Yota

 

[J1000]

check this thread out.https://forum.ih8mud.com/threads/stalling-not-just-in-high-hot-heavy.1069542/

@2001LC and I have done lots of thinking and moving the fuel pump resistor to inside the air box fixed it for me.

I did away with the fuel pump resistor altogether so now the pump runs at 12v all the time. Truck has never run better. Got the idea from @white_lx

 

[Pskhaat]

I did away with the fuel pump resistor altogether so now the pump runs at 12v all the time. Truck has never run better. Got the idea from @white_lx

Talk me through this. Removing the resistor will cause the fuel pump to pull whatever amperage it would naturally have, as well as some level of voltage increase from nominal (not sure how much). Do we know that the fuel pump is supposed to be running at 13.8VDC? Was the resistor there to reduce the delivered pump voltage specifically?

 

[jerryb]

It was there to quiet the pump noise. Resistors are cheaper than insulating a fuel pump.
I seriously doubt there were any pump life longevity ambitions.
I made and sold a few fancy bypass connectors for it.
I don't have any more but there is a thread. Many ways to delete it.

You want fuel to speed through the rails, not sit around at a lower flow rate spending more time on the front of the engine.
Sorry to say, moving it to the airbox is silly. You want hotter air going in? or you want a fan on your resistor? 200 degree heating element in your airbox, no my friend.

Dead on the side of the road, people should just insert a plain wire shorting the female terminals at the resistor.

 

[Pskhaat]

It was there to quiet the pump noise. Resistors are cheaper than insulating a fuel pump.
I seriously doubt there were any pump life longevity ambitions.
I made and sold a few fancy bypass connectors for it.
I don't have any more but there is a thread. Many ways to delete it.

You want fuel to speed through the rails, not sit around at a lower flow rate spending more time on the front of the engine.
Sorry to say, moving it to the airbox is silly. You want hotter air going in? or you want a fan on your resistor? 200 degree heating element in your airbox, no my friend.

Dead on the side of the road, people should just insert a plain wire shorting the female terminals at the resistor.

I have not put anything in my airbox nor have added a fan to the resistor (though maybe not a bad idea). I'm curious if a switched bypass is a good idea.

 

[J1000]

Talk me through this. Removing the resistor will cause the fuel pump to pull whatever amperage it would naturally have, as well as some level of voltage increase from nominal (not sure how much). Do we know that the fuel pump is supposed to be running at 13.8VDC? Was the resistor there to reduce the delivered pump voltage specifically?
View attachment 3451625

Other way around. The resistor will reduce the voltage but the amperage will probably be the same, or maybe slightly more. Just about every car on the road with an electric fuel pump runs at battery voltage. The 100 series is the only vehicle I know about that lowers the voltage with a resistor. The fuel pump should actually run cooler at higher voltage. More voltage = less amps, amps create heat. Also, as a resistor heats up, it increases its resistance. So the hotter the truck gets, the lower the voltage to the fuel pump gets. It was probably done as a MPG or emissions thing that only matters on an EPA rolling road.

 

[Pskhaat]

Other way around. The resistor will reduce the voltage but the amperage will probably be the same, or maybe slightly more. Just about every car on the road with an electric fuel pump runs at battery voltage. The 100 series is the only vehicle I know about that lowers the voltage with a resistor. The fuel pump should actually run cooler at higher voltage. More voltage = less amps, amps create heat. Also, as a resistor heats up, it increases its resistance. So the hotter the truck gets, the lower the voltage to the fuel pump gets.

I'm all about more voltage in general, but I'm also super curious as to this. I do wonder if Gulf-spec 2UZs have the resistor? Can't we rather just jump the wires at the connector?

 

[J1000]

I'm all about more voltage in general, but I'm also super curious as to this. I do wonder if Gulf-spec 2UZs have the resistor? Can't we rather just jump the wires at the connector?

View attachment 3451679

Yeah that would work too. Easy enough to jump them in the fuse box, though.

 

[lehiguy]

I LOVED your cypress green LX! But I hear ya - same old problems on old trucks eventually gets OLD

Glad to hear you’re still in a Yota

Thanks! I liked it too, but that shutting down thing got old. I think I had it fixed right about the time a new issue arose; the steering rack disassembled itself in the Walmart parking lot. No sooner did I have that under control (almost, still needed Tech Stream to sort out the BS) when the timing belt failed and the engine was toast. That's on me, but still, too much crap going on with that rig. The 4Runner is superior off road, it climbs things the 100 just wouldn't. I suspect the weight difference is the main reason, and I can drive it anywhere and never worry that it will pull some trick on me.

 

[bozncsurf]

Thanks! I liked it too, but that shutting down thing got old. I think I had it fixed right about the time a new issue arose; the steering rack disassembled itself in the Walmart parking lot. No sooner did I have that under control (almost, still needed Tech Stream to sort out the BS) when the timing belt failed and the engine was toast. That's on me, but still, too much crap going on with that rig. The 4Runner is superior off road, it climbs things the 100 just wouldn't. I suspect the weight difference is the main reason, and I can drive it anywhere and never worry that it will pull some trick on me.

Sounds like you had enough. And with what you described those were not small issues but big expensive ones.

I trail ride with quite a few 4runners and no doubt they do well offroad (better in most instances) but there are certainly trade offs (that have been discussed extensively on here so need to visit that).

Im glad you found your “happy place”

 

[hoser]

The 100 series is the only vehicle I know about that lowers the voltage with a resistor.

Common on other Lexus's of the same time period ~2005. But actually, the 98-02 100's did not have it.

 

[white_lx]

Common on other Lexus's of the same time period ~2005. But actually, the 98-02 100's did not have it.

Before the resistor, the fuel pump speed was controlled by a 'fuel pump ECU' . There were 3 different fuel pump speeds speeds. It looks like the introduction of the resistor was to reduce component cost and/or to increase reliability. From the 2000 LX repair manual:

The fuel pump speed is controlled at 3 steps (high speed, medium speed, low speed) by the condition of the engine (starting, idling, light load, heavy load), when the engine starts (STA ON) or heavy loads with engine high speed, the ECM sends a Hi signal (about 3.8 V) to the fuel pump ECU (FPC terminal). The fuel pump ECU then outputs Hi voltage (battery positive voltage) to the fuel pump so that the fuel pump operates at high speed. When the heavy loads with engine low speed, the ECM sends a Mid signal (about 2.5 V) to the fuel pump ECU (FPC terminal). The fuel pump ECU then outputs Mid voltage (about 10 V) to the fuel pump so that the fuel pump operates at medium speed. When the idling or light loads, the ECM sends a Low signal (about 1.3 V) to the fuel pump ECU (FPC terminal). The fuel pump ECU then outputs Low voltage (about 8.5 V) to the fuel pump so that the fuel pump operates at low speed.

Interesting data point: the 2001-2006 Lexus LS430 also has a fuel pump resistor.