IS250 - cranks, just about to start, but doesn't

[Linas.P]

What an exciting story I have... (not really).

Got myself a beater IS250 from salvage, rougher that one can imagine car to ever be, but it was cheap so... did basic checks, fluids, Battery - all "good" by the virtue of existing. Car was not marked as running, which is Copart terms means that it doesn't, but to my surprise came of the trailer on it's own power and without me needing to even boost it. 

Anyway, it was running just "fine" - code P0031 for oxigen sensor, but nothing stopping from starting. As well, when I gave it some beans and codes P0761/P0781 - gearbox solenoids issues. 

Booked it for Lexus service today (by the way they still do essential care, you just need to ask) and as luck may have it - the car won't start today. The weird thing, car was running until yesterday, the only unusual things I did - I filled full tank of premium fuel, washed it and got it fully up to temp to make sure it is good to go for a service today - and it was running sweet. 

My only guess - car freaked out after being washed for first time ever, after tasting premium fuel and just got shy when it realised I am taking it for proper service?!

Battery is fully charged, car cranks, starts for a half-a second and then dies. No error codes. Seems to me like fuel problem, maybe injectors, cold start injector? As well if I leave ignition ON I can hear funny noise at the back of the engine (like fuel pump priming or trying to prime maybe). Any ideas? 

noise at the back of the engine 

cranking noise

 

[peniole]

I hear that same noise when i open the driver's door on mine, sounds like an electric pump/priming.

Check vacuum hoses. Could you have dislodged one?

see: https://oards.com/causes-of-a-car-starts-then-dies-immediately/

[Linas.P]

Yes, the noise sounds like priming, but pump is in the tank, so it should be coming from rear of the car and it shouldn't prime continuously.

Another weird thing is that car was running fine yesterday, so it has to be something happening in last 12 hours. If it would have been dead straight from the auction, then all bets are off, but now it is just bizarre. 

Because just going through common causes - none of them would allow car to run one day, but suddenly stop another day i.e. say there is vacuum leak, or fuel pressure sensor, or MAF faulty, then it would have been there yesterday and car wouldn't have run at all.

I am kind of leaning towards theory that it may be something to do with blocked fuel hoses, fault in injectors... maybe by refilling the car with fresh fuel I dislodged some crap and it blocked something down the line. It is just weird case of car suddenly not running... although considering it's current state I don't think it is all that surprising, perhaps it was the case of "not if, but when".

It seems I will have to check every single part of it, as there is no quick fix... and annoyingly no codes to point to any direction. 

[Barry14UK]

14 minutes ago, Linas.P said:

 

I am kind of leaning towards theory that it may be something to do with blocked fuel hoses, fault in injectors... maybe by refilling the car with fresh fuel I dislodged some crap and it blocked something down the line. It is just weird case of car suddenly not running... 

That's my thought too.  Unfortunate car is now pretty full of fuel as complete system may need to be flushed through including tank if this is indeed root of problem.

[Mr Vlad]

Blimey Linas that's weird but as stated I'd suggest that since you filled the car up with premium fuel and with that fuel having detergents within its probably started a clean up of the fuel system but unfortunately its dislodged some crap hence blocking the fuel lines.

Test this by seeing if any fuel comes out of a fuel line in the engine bay. Yes the system is pressurised but if it blocked then no pressure. 

Or since you paid next to nothing for it let Lexus take a look and sort. Even if they charge 2k you'll be quids in yes?

Oh and welcome back to is250 ownership 👍

[ColinBarber]

1 hour ago, Linas.P said:

Yes, the noise sounds like priming, but pump is in the tank, so it should be coming from rear of the car and it shouldn't prime continuously.

The high pressure fuel pump is in the engine bay, I think at the back on the IS250 - not sure if it should continuously run like that or not though.

[Linas.P]

22 minutes ago, Mr Vlad said:

Or since you paid next to nothing for it let Lexus take a look and sort. Even if they charge 2k you'll be quids in yes?

For £500 - yes... for £2k not really, would not be economical to repair then. That said I would be happy for Lexus to sort it out, but most rational decision would be to at least narrow down the issue. Because now it seems it could be literally anything... and diagnostics being charged at £195/hour it may take 8 hours to diagnose what it is, even if the fix is £50 to blow fuel line with compressed air. 

8 minutes ago, ColinBarber said:

The high pressure fuel pump is in the engine bay, I think at the back on the IS250 - not sure if it should continuously run like that or not though.

Ok, so that will be it. Looking at maintenance manual it seems it should stop once it reaches right pressure (primes), just more reason to point to fuel delivery - blocked line or faulty pressure sensor. So basically it never reports right pressure and the pump keeps trying to prime. 

What I will try next is to pry fuel line open and see if I get splashed with pressurised fuel 😅

 

 

[cruisermark]

You can see a fuel pump being replaced if it is that - forward to 21:00

 

[Linas.P]

Oh yes, I have no problem to replace fuel pump if that is indeed the issue. The problem is to figure out where the issues is. Where I am at the moment - I am waiting until I finish working today and will need to move car inside the garage and start troubleshooting fuel delivery.

It is good video (seen it before), I guess it is more user friendly than following the steps in maintenance manual, more "visual".

[Linas.P]

Actually, I probably should have mentioned that - but I guess I have good alternative. I have Lexus Roadside Assistance (still valid since I got it with RC), so in theory I can just call them in and let them figure out what is going on. Maybe they are not as good as Lexus, but certainly better than qualified idiot like me. On top of that it would be totally free and if they can't figure it out, then they can take it to the Lexus for diagnostics with free deliver/return + courtesy car 🤯

I would still have to pay Lexus diagnostics in this case as car is not warranted, but free service takes me quite long way!

[Barry14UK]

4 hours ago, Linas.P said:

 

Booked it for Lexus service today (by the way they still do essential care, you just need to ask) 

 

I am sure I am not the only one interested in this aside.  When I took my car into Lexus Cheltenham for service this year, I think it was August or September, they were adamant that 'Essential Service' was no longer an option.  Grateful if you will advise which dealership offered this.

Good luck with sorting your problem.  It seems to me that blockage rather than pump could be problem. 

[Linas.P]

12 minutes ago, Barry14UK said:

I am sure I am not the only one interested in this aside.  When I took my car into Lexus Cheltenham for service this year, I think it was August or September, they were adamant that 'Essential Service' was no longer an option.  Grateful if you will advise which dealership offered this.

Good luck with sorting your problem.  It seems to me that blockage rather than pump could be problem. 

Yes I was a bit cheeky and to my surprise they said yes! It is officially discontinued, but as I understand it is down to individual dealership discretion to offer it. I spoken with Jemca (Edgeware Road) and Hills Group (Woodford and Hainaut) - both were able to offer it, although I got impressions Jemca subcontracts it. Hills Groups seems to do it themselves - the guy on the phones was like "please give me your reg and and will see if I get an option to book it as Essential..." and indeed there was still option to do that. In either case you get Lexus stamp in the book and same old good prices (£185 for minor is steal, although £375 for major is probably not as good, depending on service needed I may go with Lexus normal service as it include little bit more items).  

[peniole]

4 hours ago, ColinBarber said:

The high pressure fuel pump is in the engine bay, I think at the back on the IS250 - not sure if it should continuously run like that or not though.

You're right Colin. It should prime and then shut up. Does not work continuously. It does vary though based on how long you've left it not running, how cold or hot, parked outside...etc. Sometimes can be a couple of seconds, sometimes considerably longer but still in the seconds range not continuous.

[Beamish]

 

As I understand it the high pressure fuel pump located at the rear of the engine is mechanically driven from one of the camshafts as opposed to the low pressure electric lift pump located in the tank.

 

[Exdee]

Have you ruled out engine flooding?

Floor the accelerator and then try to start the car. You may need to do it a couple of times. 

 

[Beamish]

 

+ 1 on the flooding.

Keep the pedal on the floor.

Always best to try the easy fix first!

[BC99]

Have you tried disconnecting the Battery for 10 minutes?

Trying to think what that noise is, not the throttle body? pull the cover off the engine and see if it's that or something else.

I can't help thinking it may be water related, do you have an OBD device to see if any new errors are being thrown up? Although could be the issue that lead to it being described as a non-runner and dodgy connection or something, perhaps the trailer trip shook things up enough to get it working.

[Linas.P]

30 minutes ago, Exdee said:

Have you ruled out engine flooding?

Floor the accelerator and then try to start the car. You may need to do it a couple of times. 

Tried that - sometimes when engine struggles to stay on idle it helps... but in my case I don't get to idle at all. Flooding - unlikely with DI. Well... unless leaking injector, but I would expect it to run rich at most. It is not like on carbs where you can hydro lock the engine. If it would be easy to do I would check spark plugs, but it is major **** pain on IS250. 

9 minutes ago, BC99 said:

Have you tried disconnecting the battery for 10 minutes?

Trying to think what that noise is, not the throttle body? pull the cover off the engine and see if it's that or something else.

I can't help thinking it may be water related, do you have an OBD device to see if any new errors are being thrown up?

I could try to disconnect it, can't see how that would hurt, but can't see how disconnecting the Battery would help. Resets ECU maybe. I mean perhaps good idea in desperation.

The noise is quite conclusively high pressure pump which sits at the back of the engine. 

When you say water related, do you mean after washing? I didn't was engine bay so not sure why it would be.

I have OBD reader and there were some codes present anyway, but nothing which would prevent car from starting as per original post. When car failed to start I have cleared the codes and there are no codes now - I believe because engine doesn't start and ECU can't finish the start-up check, so don't get to the point of reporting P0031, which I would expect to reappear as soon as car starts. 

[Linas.P]

Not much of the update so far, tried checking if there is fuel pressure, but found fuel hoses to be quite stiff and fragile to the point where I was afraid to crack them and thus I didn't proceed any further. Lexus Roadside assistance option didn't work out as I forgotten car has to be road legal and by extent have valid MOT for cover to work. As it happened in my case, MOT has run out whilst the car was in auction and my plan was to get it done together with the service. Either way no MOT, no Lexus roadside assistance cover, which is fair enough.

I started by removing all the plastics in the engine bay and just checking connectors for everything to see if anything obvious is out of place. As I didn't have much luck with fuel hoses under the bonnet, my next check ill be to check fuel pump side in the tank, maybe it is less perished there and I can at least test fuel pump and rule out that problem. Obviously, looking at how the soft fuel lines looks in the engine bay I would not be surprised that this may causes issues and by itself could be fire hazard, so once car is running I guess I need to see the prices and availability for replacement hoses.

[BC99]

23 hours ago, Linas.P said:

Tried that - sometimes when engine struggles to stay on idle it helps... but in my case I don't get to idle at all. Flooding - unlikely with DI. Well... unless leaking injector, but I would expect it to run rich at most. It is not like on carbs where you can hydro lock the engine. If it would be easy to do I would check spark plugs, but it is major **** pain on IS250. 

I could try to disconnect it, can't see how that would hurt, but can't see how disconnecting the battery would help. Resets ECU maybe. I mean perhaps good idea in desperation.

The noise is quite conclusively high pressure pump which sits at the back of the engine.

conclusively high pressure pump?

The throttle body sits above the pump.

That being said, does sound similar to what someone posted on another lexus forum here (if allowed to link to others) Seems like that was the high pressure pump... Can't quite get my head around it as it's driven by the camshaft rather than the electric pump that's under the rear seat, so faulty valve in it or something.

With disconnecting Battery i just wondered if the higher knock rating of fresh fuel would have made it more difficult to start on the learned settings that worked with stale stuff, but probably makes no difference.

[Thackeray]

On 12/9/2021 at 9:26 AM, Linas.P said:

cranking noise

This brought back a memory for me from 20 years ago. A two-year-old Mercedes diesel had exactly the same pattern of briefly starting, then not firing at all; then briefly starting, then not firing at all. The car was under warranty and the dealer struggled to find the cause. Although this sounds almost exactly the same, it's unlikely that it's the same cause. But just in case it sparks any ideas, I'll tell you what the dealer tried before solving it.

First of all, it only happened in winter. The car was started from cold, driven three or four miles - not enough to fully warm up - then stopped. And then it wouldn't restart and instead did the pattern in the youtube recording above.

I called the breakdown service but after 20 minutes of cooling down it had fixed itself before they arrived. But it kept happening and the dealer made three attempts to fix it.

First, they said it was air in the fuel supply and changed some part which they didn't specify. By then it was summer and the problem disappeared until the cold weather.

But when November weather came, it did it again. This time the dealer changed the catalytic converter - or so they said. They didn't give a convincing explanation of why. But it didn't fix the problem.

At the third attempt, they changed camshaft and crankshaft sensors and that seemed to fix it. The problem went away and didn't come back.

I don't suppose any of this is going to help with a completely different car. But the recording of the symptom sounded so familiar that I thought it might be of interest and maybe prompt some ideas.

[Linas.P]

Small progress today. Got to the fuel pump in tank - did not removed it yet, because I know it would result in major fuel spill, considering it is full. In either case checked the pump with multi-meter and it checks out. Unplugged fuel line in the engine bay and it was full of fuel, then disconnected the line at the tank and let it drain as much as it does naturally and the line on engine side was dry. Reconnected everything, turned on ignition and could hear fuel pump priming in the tank, checked fuel line at the engine side again and it was full again. Sure it would be ideal to blow it with compressed air just to make sure, but low pressure side doesn't seems to be blocked. Obviously, this does not prove fuel pump provides sufficient pressure and I can't test it because I don't have right gauge, but it provides enough fuel for the car to at least start.

Just for good measure I tried cranking the car again after disconnecting everything, but me fiddling with low pressure fuel delivery side and getting petrol in my face dozen times has not changed car's mood. 

Next step will be to try to diagnose high pressure side.

As well looking at throttle body it was full of black sludge (probably blow back from PCV), so it seems to me it would be good idea to get the "snake nest" off and clean it + inspect what in going on inside. 

[Linas.P]

Still struggling to find any issue, but at the same time getting overwhelmed with test results. although fuel "supply" pump checked out and the relay checked out, but I am getting results way different than expected from integration relay and harness. Option 1: my cheap multi-meter is just no good 2: I have issue with ground (which would be very interesting issue), or 3: (and most likely) I am idiot who can't measure it correctly.

Still didn't manage to measure high pressure pump, because even after removing intake I still can't get probe onto connector. Although pump resister checks out. Who knows... Ohh an clearly there was somebody with 2 left legs instead of hands under the  bonnet, common signs of missing blots, broken clips and scratches on intake manifold - that is my "favourite" thing on used cars. 

I am kind of tempted to remove intake manifold and get borescope into cylinders and see what's is down there... but apart of suggestion that engine may be flooded (which I doubt) I won't see much in there. Engine turns freely and it was running, so it is not like it have blown the piston whilst parked.

Apart of that ordered myself a cable for Techstream which I hope will make more sense than manually cheeking connections i.e. in Techstream I could initiate fuel pump initialisation and just rig the bottle on the line and see if there is fuel flow (more ideally gauge, but bottle will do for now). As well I need do devise the plan how to drain fuel, because I can't get to the actual pump assembly with full tank.

To be honest I hate diagnosing modern cars (says the guy who bought non-runner Lexus from auction) and it is so bizarre that it run and suddenly stopped... Anyway story will continue for some time I am sure.

[Linas.P]

Ok... 

So the status update so far - low pressure side work, high pressure side works (I think), ignition works, there is spark, spark plugs little bit dirty but dry (gap seems a bit large, so certainly due for replacement), cylinders just slightly damp or it may be just carbon build-up, but nothing unexpected (certainly not flooded).

I was able to get car running for like 5s, by just putting ~5ml of petrol directly into cylinders. Got some black smoke from tail pipe as expected (running rich on cold engine).

So what am I left with in terms of theories:

- injectors drivers

- fuel pressure sensor (meant to check it yesterday, but it requires 5V to be applied to 1&3, before checking voltage between 2&3, which is a bit tricky).

- ground to some of the components intermittent

- it could still be either of the pumps, I mean I confirmed they work and measure correctly, but I can't check the actual pressure, although my guess is that they would provide enough fuel to start, just maybe not enough to idle nicely + I would get VSC and code for low pressure, whereas currently I get nothing. 

[peniole]

Assuming both pumps are running, then sounds like a lean run (too much air, too little fuel). Large vacuum leak, really off sensor reading, clogged fuel filter or injectors are causes that come to mind.