Upon starting, rough Idling, then stalls after about 3-6 seconds

[suzie]

Dear friends,
Our trusty 2004 (Australian market RHD) LX470 cannot be driven now. It's happened once about 2 weeks ago, when I stopped the engine to unload groceries, whereupon an attempt to restart the car within 10 minutes of stopping gave the same symptoms :
(1) Car engine cranks strong & fires up immediately.
(2) However, it idles very rough then stalls within 3 to 6 seconds.
(3) I left it alone for an hour, came back & it started fine like nothing happened earlier. I drove for next 2 weeks without any trouble at all.
(4) No CEL came up at all.

Yesterday, however, it stalled & "resting" the engine for an hour (plus overnight) still won't start up properly. Just fires up strong, rough idle for 3-6 seconds & then stalls.

Has someone experienced this kind of intermittent sympton before? I've tried to search the forum, and the closest (but not quite the same behavior in posts) mentioned possibilities of either fuel pump, fuel filter, MAF + throttle body cleaning needed.

We're going try with cleaning MAF & throttle body tomorrow to see if that helps, before ordering fuel filter to see if it helps.

Recent maintenance history : The serpentine belt was replaced about 1.5km ago.

Any hints/tips/suggestions would be greatly appreciated. We live in a very remote area & hoping to see if it is something we can deal with ourselves for now. Thanks in advance & have a great day folks!

 

[AlpineAccess]

First guess is fuel filter, then fuel pump.

 

[JunkCrzr89]

First guess is fuel filter, then fuel pump.

I agree.

 

[yukon]

Another vote for fuel system.

 

[Eicca]

Fuel system is first guess, second is a cam or crank sensor wire that got rubbed by the serpentine belt.

 

[2001LC]

Check for codes, regardless of no CEL.

We do seem to be seeing a lot of fuel pump failures lately. They don't often yield a confirmed or pending code. But sometimes do, with a pending lean code.

I just had one of these no codes a few moths ago. I was going to try pinching off fuel return line. Edited: Pinching could damage line!Then crank engine for long duration with strong battery. It "may" have increase fuel pressure just enough to start. I was going to use vise grips with short pieces of fuel hose over business end, to protect return line while pinching. But it started the day I went to try this before I pinched off line, so not sure if test/pinch off would have worked.

I replaced the fuel pump and filter on a hunch, based clues, and it's worked since. But it's symptoms where a little different. In that it either started or did not.

Assuming you've a 2UZ-fe V8. Fuel line coming from around the back side of intake manifold is return, not the line going to fuel damping device from fuel filter.

 

[suzie]

Thanks for new lead, Eicca.

I just looked around and don't seem to see any wires close to serpentine belt.

May I know if there's a specific location to check please? Thanks again.

Fuel system is first guess, second is a cam or crank sensor wire that got rubbed by the serpentine belt.

 

[suzie]

Thanks for the detailed info, 2001LC. Really appreciate it. Don't have a reader to get codes, but will try to see if I can get help on that.

For now, the plot thickens, folks. Here's what I did and the outcome this far:

1. Bought new fuel filter and replaced the old (the fuel dripping out was very dirty, so it's time to change really).

2. Start the car and it seemed to fix the problem. For exactly 15 seconds. Engine then started to hunt with the RPM slowly dropping ever lower (at one point the CEL flashed but the RPM came back up momentarily and eliminated it), and eventually engine stalled completely.

Here's my video, kindly see if any one of you can get hints from the strange behaviour please :

I'm not really sure what to do next. Do I go get a new fuel pump & see if that's the problem? Do fuel pumps kind of semi work to create this issue?

A mechanic friend said perhaps the timing belt needs changing (?).

Thanks a bunch for chiming in, folks.

 

[Mbchance]

Thanks for the detailed info, 2001LC. Really appreciate it. Don't have a reader to get codes, but will try to see if I can get help on that.

For now, the plot thickens, folks. Here's what I did and the outcome this far:

1. Bought new fuel filter and replaced the old (the fuel dripping out was very dirty, so it's time to change really).

2. Start the car and it seemed to fix the problem. For exactly 15 seconds. Engine then started to hunt with the RPM slowly dropping ever lower (at one point the CEL flashed but the RPM came back up momentarily and eliminated it), and eventually engine stalled completely.

Here's my video, kindly see if any one of you can get hints from the strange behaviour please :

I'm not really sure what to do next. Do I go get a new fuel pump & see if that's the problem? Do fuel pumps kind of semi work to create this issue?

A mechanic friend said perhaps the timing belt needs changing (?).

Thanks a bunch for chiming in, folks.

Sounds like a fuel problem to me. Changing the fuel filter somehow primed enough fuel to give you the smooth run on the engine you experienced first then it stalls out. I’m curious to see what others think but sounds like fuel pump might be your problem. My 2cents.

 

[2001LC]

Thanks for the detailed info, 2001LC. Really appreciate it. Don't have a reader to get codes, but will try to see if I can get help on that.

For now, the plot thickens, folks. Here's what I did and the outcome this far:

1. Bought new fuel filter and replaced the old (the fuel dripping out was very dirty, so it's time to change really).

2. Start the car and it seemed to fix the problem. For exactly 15 seconds. Engine then started to hunt with the RPM slowly dropping ever lower (at one point the CEL flashed but the RPM came back up momentarily and eliminated it), and eventually engine stalled completely.

Here's my video, kindly see if any one of you can get hints from the strange behaviour please :

I'm not really sure what to do next. Do I go get a new fuel pump & see if that's the problem? Do fuel pumps kind of semi work to create this issue?

A mechanic friend said perhaps the timing belt needs changing (?).

Thanks a bunch for chiming in, folks.

Whereas it may just be coincidence it now started and ran after fuel filter R&R. That and the fact it was dripping dirty fuel, points to fuel issue yet once again. It's indication you've got some bad gas or have been getting for a long time.

These fuel pumps are multi speed. They get more power at higher RPMs and certain condition. One of those condition "may" be start up, IDK! So yes they can act this way.

After reading codes and pinching off fuel return line Edited: Pinching could damage line! for more clues. A fuel pump & tank seal along with can of 44k, Chevron techron or some good fuel systems cleaner would be next step.

 

[JunkCrzr89]

I agree with @2001LC

 

[AlpineAccess]

Where again is this vehicle located? It is possible you have bad gas. You might pull the fuel filter again, and with the hose pointed into a big glass jar have someone turn the key to accessory for a 5-10 seconds. It will "prime" and force gas into the jar. Look for sediment and or water separation.

It could be your fuel pump, but I'd test the free stuff first.

 

[gregnash]

Where again is this vehicle located? It is possible you have bad gas. You might pull the fuel filter again, and with the hose pointed into a big glass jar have someone turn the key to accessory for a 5-10 seconds. It will "prime" and force gas into the jar. Look for sediment and or water separation.

It could be your fuel pump, but I'd test the free stuff first.

Doesn't the Techstream software have an evap system test that is for the fuel pump? Know it has injector test...

 

[yukon]

Do you have a fuel pressure gauge? I don't know where you would pick up a cheap one in OZ, but it would answer your question really fast.

 

[suzie]

Thanks for all the tips, much appreciated! We've just ordered a new fuel pump & Techron fuel treatment. I'll update once we get pump installed.

 

[2001LC]

Actually fuel pressure gauge doesn't "always" reveal a week pump. Not to say it will not. The ones I've heard about only show a pound or two low, not alarming.

I know one case went on for 90K miles. Dealership hooked up pressure gauge multiple times. Tried driving in heat and over the rocky mountain passes with fuel pressure gauge and tech stream hooked up. Finally on a hunch or something, they install a new fuel pump, problem solved. See Snowy in my master thread.

I just had another case, I've not posted on a 07 at 160K miles). It seems more common in the 06-07, which is when Toyota changed to a smaller fuel pump.

All these pumps are multi speed. It seems the 06-07 tend to run week at the lower speeds. But even the 99-05 fuel pumps, seems we're seeing more issues with these days.

Fleet is aging!

 

[suzie]

Update on intermittent issue :
1. The fuel pump has yet to arrive but the Caltex Techron arrived last evening.
2. On a whim, I decided to crawl under car this morning and drain my half-full tank to just under 1/4 full, then emptied the Techron in. (I know some cars do not have a fuel tank drain plug, but mine does. If you look under car, there will be several drain holes for tank protector; if you see one of them is especially large, then that's where the fuel tank drain plug is). The fuel looked quite clean to me.

3. I then started the engine, and this time it fired up with slightly rough idle for about 5 seconds then settled down quite smooth. I figured the Techron can't possibly work THAT fast, can it? Or thinking back, perhaps right after installing new fuel filter, I needed to ignore those few initial stalling & keep on cranking engine until all air trapped in fuel line have dissipated (?).
4. I'm a little troubled because I drove it all day without any issues. I'm now wondering if the Techron combined with my earlier reference to "resting" the engine has helped somewhat.

Anyway, we're just going to keep driving truck now and wait to see if the intermittent issue pops up again. If it does, then we'll install the new fuel pump that's arriving soon. For now, we'll drive and monitor if the new fuel filter + Techron has solved the issue.

Thanks again for all the help! I'll report back on status down the road.

 

[AK Wes]

I know you are stating that you have an Australian RHD Land Cruiser, but I'm curious if you are in a cold or warm climate while taking the video? I have had issues with mine doing almost the same exact thing you are experiencing, but only in cold weather.

Thanks

 

[suzie]

I know you are stating that you have an Australian RHD Land Cruiser, but I'm curious if you are in a cold or warm climate while taking the video? I have had issues with mine doing almost the same exact thing you are experiencing, but only in cold weather.

Thanks

Hi AK Wes, we're in warm weather. So, I'm not sure if the underlying cause is the same. Cheers!

 

[JunkCrzr89]

Good news! I’d probably go ahead and install the new fuel pump anyways. 16 years on the original is good enough at this point.