I hope there is someone who can assist me with my issue. 2006 LX470, 180K . I have owned it for close to 2 years- It was involved in a minor front end collision before I bought it. No airbags. The LX retains all original factory sheet metal. What was replaced was the Bumper and 1 headlight assembly. Installed a TJM bumper and removed the running boards. I had ALL the fluids changed, belts hoses, etc....water pump.....etc. Ran great until about 6 months ago, it died while driving several times. No Codes. We replaced the fuel pump with a factory part and it ran great for 5 months. Then it started dying again-- on the freeway, it cuts off and restarts itself. And then at low speed, it will die- and will restart on the second attempt. No Codes. So we changed the Fuel Pump relay. Great for a week and then it died again this AM. HELP
HELP! LX470 cuts off while driving (1 Viewer)
- Thread starter Samuel5090
- Start date
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Let's start with the most basic. What is the condition of the battery and it's connections, including grounds to engine and body? Also, has the vehicle been exposed to a lot of rain or washing? water intrusion can plague these vehicles.
- Thread starter
- #3
Battery is less than a year old. connections are tight - I live in Central Calif so not a lot of rain. But if I had a ground issue, wouldn't it throw a code??
- Thread starter
- #4
Also, the radio and electronics never cut off when the engine dies
the fact that it is not throwing a code makes me think it's an electrical problem/bad connection somewhere. Seems like you may be on the right track with fuel pump related components as it works for a while after you mess with it. The underhood fusebox has had issues like THIS so it wouldn't be surprising if the fuel pump relay wiring could have issue as well (if the fuel pump relay is in there).
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- Thread starter
- #7
Thanks for this- I passed it along to my Toyota mechanic-- He says he has never seen anything like this with any 4.7 powered vehicle
EFI fuse contacts, fuel pump failing?
If the gap is too big it could make sense why it randomly cuts out while driving.
If the gap is too big it could make sense why it randomly cuts out while driving.
- Thread starter
- #9
New factory fuel pump and filter 5 months ago.
YezusLX
SILVER Star
I do not know if this is relevant here but I just had something like this happen to me on my 1999 LX 470. I was picking it up from window tinting and heading to the dealer to pick up some more parts for baselining. Truck stalls in the turn lane. Dead. Nothing. No CEL no DTC. Radio, lights, and everything stays on. Push this big bitch into the parking lot. Attempt to start again. Runs briefly then shuts down. Never runs again after that. Tow it to the dealer. Three days of guessing later I suggested someone check the timing belt because PO had done it with some shade tree mechanic. They pull the timing cover. Find out she's jumped timing. I buy a tensioner online at another dealer. Bring it to them. Boom! Runs again like a champ. No contact. I got lucky as all get out. A thousand bucks in labor and my own diagnosis. She drives away leaking P/S fluid. I hope this gives you some direction or at least something to cross off the list.
- Thread starter
- #11
Thanks-- It runs -starts fine-- but occasionally it will just die. Starts right back up on second try. Then runs great---No Codes
Do these trucks have a cps? That’s a part on many vehicles that can act like this while failing BUT since you’ve had success with the fuel pump, I’d guess it’s within that wiring loom/system.
2001LC
SILVER Star
Which fuel pump rely, did you replace? Names of parts can miss lead us.
What are the ECT (engine coolant temperature) as seem through tech stream, running?
Is the security light, ever coming on with IG key in?
Have spark plugs been replace, with know good ones (not some junk China bootleg)?
Any misfire observed in tech stream?
Few thoughts:
Keep a code read plugged in, on all drives. Scan as soon as event happens, without turning off IG key. We sometime can catch a lean condition or other DTC pending. Some disappear if condition clears on next system check.
Make sure wire harness running down LH timing belt cover, is going behind fan bracket and not visible. If running in front of fan bracket. Make sure it's not rubbing serpentine belt or pulleys cutting wires.
Double check grounds firmly connected, like one at firewall to engine at heater tees.
There is a TSB on cam sensor behind RH T-belt cover. But IIRC it's a cranking issue when trying to start. But worth checking. As not only TSB. But during timing belt service. Some damage it's wires or they pull bolts retaining sensors needlessly and don't get torqued back in.
The throttle body electronic can be damage or a sensor wonky. We should get a DTC, but may only be pending. One thing I never do is open the 03- throttle body by hand. Toyota does not say not too. But I've concern with damaging electronics in throttle body. That or if the wire harness loose, could produce issue of stalling. Your butterfly could close (lean condition), cutting air from engine (running rich condition). Look at throttle body butterfly as it opens and closes, while IG key ON (engine off) and someone depress gas pedal. Does it open and close all the way, and smoothly.
Look over air intake pipes, engine and under intake manifold for signs of rodents. Those little guts cause us so many issues.
Run through fuel pump and fuel pressure regulator test by the book.
If dying at low speeds (low RPM), after running at higher RPM like 2,500+. It does point to fuel flow or pressure issue. More thoughts along this line"
1) Make sure vacuum line on fuel pressure regulator, and all points and hose of air box and vacuum hoses snug (no vacuum leaks). This includes air pipe to throttle body, where sometimes pipe is curled up allowing air in at bottom of pipe (can't see). So inspect ever point of intake and vacuum. Monitoring fuels trims can be revealing. Also inspect air filter and air tube coming into from within fender, for obstruction like a nest.
2) Most common is fuel pump in the 06-07 resulting in shut down. I would think the new OEM fuel pump took care of. But it possible you got a bad one. I've never R&R with OEM. I've only used Denso (Not Toyota Denso), which we must remove pump from cage (housing/holder). With the Denso I've never had issue. But if Denso used it must be installed correctly at all points. Which an O-ring we must install, cage set correctly and wire house block connect securely.
3) Just recently a teenage in high school near me, made an observation (very smart and observant of him). He had stall issues, after installing air pump. The pump block the fuel pump resistor which is on RH fender, which has a heat sinks. He moved the resistor into air box, which gives constant air flow to dissipating heat. It's not been very hot here yet, but to-date he's issue cleared. About the some time. A builder and I talking about this fuel pump resistor. He's seen then go bad (not 100 series) on Toyota's. He also said we must have great than 2:" cleaner (air space). They will get hot (increasing resistance) and reduce power (volts/amp) to fuel pump, by to much at low RPMs. During high RPM, ECM routs around resistor and gives full voltage to fuel pump. Fuel flow/pressure drops at low RPM to much if this reply bad or over heating.
What are the ECT (engine coolant temperature) as seem through tech stream, running?
Is the security light, ever coming on with IG key in?
Have spark plugs been replace, with know good ones (not some junk China bootleg)?
Any misfire observed in tech stream?
Few thoughts:
Keep a code read plugged in, on all drives. Scan as soon as event happens, without turning off IG key. We sometime can catch a lean condition or other DTC pending. Some disappear if condition clears on next system check.
Make sure wire harness running down LH timing belt cover, is going behind fan bracket and not visible. If running in front of fan bracket. Make sure it's not rubbing serpentine belt or pulleys cutting wires.
Double check grounds firmly connected, like one at firewall to engine at heater tees.
There is a TSB on cam sensor behind RH T-belt cover. But IIRC it's a cranking issue when trying to start. But worth checking. As not only TSB. But during timing belt service. Some damage it's wires or they pull bolts retaining sensors needlessly and don't get torqued back in.
The throttle body electronic can be damage or a sensor wonky. We should get a DTC, but may only be pending. One thing I never do is open the 03- throttle body by hand. Toyota does not say not too. But I've concern with damaging electronics in throttle body. That or if the wire harness loose, could produce issue of stalling. Your butterfly could close (lean condition), cutting air from engine (running rich condition). Look at throttle body butterfly as it opens and closes, while IG key ON (engine off) and someone depress gas pedal. Does it open and close all the way, and smoothly.
Look over air intake pipes, engine and under intake manifold for signs of rodents. Those little guts cause us so many issues.
Run through fuel pump and fuel pressure regulator test by the book.
If dying at low speeds (low RPM), after running at higher RPM like 2,500+. It does point to fuel flow or pressure issue. More thoughts along this line"
1) Make sure vacuum line on fuel pressure regulator, and all points and hose of air box and vacuum hoses snug (no vacuum leaks). This includes air pipe to throttle body, where sometimes pipe is curled up allowing air in at bottom of pipe (can't see). So inspect ever point of intake and vacuum. Monitoring fuels trims can be revealing. Also inspect air filter and air tube coming into from within fender, for obstruction like a nest.
2) Most common is fuel pump in the 06-07 resulting in shut down. I would think the new OEM fuel pump took care of. But it possible you got a bad one. I've never R&R with OEM. I've only used Denso (Not Toyota Denso), which we must remove pump from cage (housing/holder). With the Denso I've never had issue. But if Denso used it must be installed correctly at all points. Which an O-ring we must install, cage set correctly and wire house block connect securely.
3) Just recently a teenage in high school near me, made an observation (very smart and observant of him). He had stall issues, after installing air pump. The pump block the fuel pump resistor which is on RH fender, which has a heat sinks. He moved the resistor into air box, which gives constant air flow to dissipating heat. It's not been very hot here yet, but to-date he's issue cleared. About the some time. A builder and I talking about this fuel pump resistor. He's seen then go bad (not 100 series) on Toyota's. He also said we must have great than 2:" cleaner (air space). They will get hot (increasing resistance) and reduce power (volts/amp) to fuel pump, by to much at low RPMs. During high RPM, ECM routs around resistor and gives full voltage to fuel pump. Fuel flow/pressure drops at low RPM to much if this reply bad or over heating.
- Thread starter
- #14
WOW-- thank you so much!
- Thread starter
- #15
Which fuel pump rely, did you replace? Names of parts can miss lead us. Fuel pump relay-replaced by LC tech -assume main relay
What are the ECT (engine coolant temperature) as seem through tech stream, running? Temp appears normal
Is the security light, ever coming on with IG key in? Not that I noticed
Have spark plugs been replace, with know good ones (not some junk China bootleg)? Yes - replaced at 174,000 ( now 180,000)
Any misfire observed in tech stream? Tech says No Codes
- Thread starter
- #16
BTT
Have you isolated if the stalling happens both when the air conditioning is ON (compressor turned on) and OFF?
Can you expand on why you might be asking this? I had a similar stall problem (no codes) last summer that has been very intermittent, but I noticed that it only seemed to happen on days when I was running the A/C. And when I say intermittent, I mean once every 2-3 months as a daily driver.
2001LC
SILVER Star
ECT observed by water temp gauge on dash, is a poor indicator. It only goes high when very hot. I read ECT thought tech stream with a blue-driver & iphone, as I drive. Many devices on the market can read ECT, as we drive.
Misfire typically do not set off a DTC (code). They're viewed through tech stream, while engine running.
I don't know what he's after ("asking"). But if your issues of stalling when AC on, with high OAT (summer OAT heat). Likely your engine coolant is running hot (over heating). Once we have and overheating event. We may have boiled fuel and damage charcoal canisters, of 03-up. The 98-02 is not as susceptible to charcoal canister damage.
A properly maintained coolant system is so important. Which start with radiator fin cleaning.
Radiator fins need cleaning! Alert Alert Alert
I've a 06LC w/192K I just bought. In reading history I found PO complained of engine temp raising when both front and rear AC on. Toyota Dealership diagnosed with clogged radiator fins. Recommended new OEM radiator, $600 for the US spec Radaitor plus coolant and labor. They should have added...
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- Thread starter
- #20
I believe the last time it happened, the compressor was off. It was in the morning and cool and I had driven about 10 miles.
