2008 IS250 Crank, No Start

chr15gb · May 15

My car was running fine, parked up then 4 days later it won't start.
Engine cranks over but doesn't catch and start, just cranks then dies.

Battery is about 2yrs old and reads 12.3V. I charged it anyway but no change.
I used Jump Leads from another car but no change, just cranks and doesn't start.

No engine light and no error codes whatsoever.

Checked all fuses both in Engine bay and under the dash - all good
Checked the big fuse block in the engine bay - continuity across the whole bar so all good.

I can hear the fuel pump prime when the ignition is turned on.

Running Techstream (see Graph):

Ignition ON
Engine OFF (obviously)

I can turn the Fuel Pump on and can hear it running.
Fuel Pressure is 46 psi in the graph but mostly 44psi, seen it as low as 26psi after I opened the fuel cap to release pressure.
I can't find anything definitive but as much as I can tell, the LPFP should provide 30-60psi so I guess that is okay, also as I can see a changing pressure, the Fuel Pressure Sensor seems okay.

The pressure does not change when I'm cranking though. I would expect to see the fuel pressure leap up when the HPFP takes over and ramps it up nearer the Fuel Pressure Target Value (way higher than 46psi).

I would aslo expect to see some kind of Duty Cycles on the Fuel Pump but they remain static at 0%

I'm not sure if I'm barking up the wrong tree entirely, normally a broken starter just clicks but this one cranks. I though perhaps it is cranking a bit too slugishly so doesn't have the Oomph to catch properly, not discounted this yet but I'm running out of ideas.

I did pull a couple of spark plugs and both seem fine.

Air Supply - Good
Fuel - Questionable
Spark - No Errors or engine lights. I would hope if there was nothing going anywhere it would flag an error.

Any ideas before the big hammer comes out?

Radiator was recently changed as it split and covered the engine bay. Engine did not overheat.
Coolant level stable
Oil looks fine
Head Gasket tester used with no change to the liquid in the test tube.
Car has been driven over 200miles since the radiator change with no problems.

Linas.P · May 15

Sounds a lot like my problem with immobiliser. Although in my case it would fire once and then die.

No error codes part is really annoying as with the complexity of modern cars it is like finding needle in the hay stack, even with codes is often difficult, but without the codes it is damn hard.

I have few ideas, but they all would (or at least in theory should) trigger the error codes e.g. fuel pressure sensor, crank shaft position sensor... things like that should trigger the codes if they don't work.

So in principle - you say you have air, not sure about fuel and not sure about spark? Regarding air - check if ETB operates as expected, could be dead ETB (again should give code, but who knows), it would be good to test spark with the tester (light)... also you can try backyard mechanic trick of spraying some starting fluid into intake... in which case if engine starts even for a second it would prove you have spark and issue is most likely fuel. If you had dead ETB, then car should still start and idle (ETB does not full close for this exact reason).

What worries me is you no-code issue, almost like comms with ECU dead, because logic says - if engine does not start then there should be errors, many of them! So the worry here would be that something electrical is shorted, which is real disaster on these cars. You could try full ECU reset with the paper-clip and see if that maybe wakes it-up and shows some codes.

chr15gb · May 15

Thanks Linus. I did take the camshaft position sensors out, stared at them, cleaned them, spayed contact cleaner in the plugs and refitted.
Same for Vanos solonoids to ensure they are free to move about.

Not done Crankshaft sensor, not tried to locate it but from a youtube clip I saw, looks a swine to access.

I do have a spark plug light tester but not used it yet. I was convincing myself if there was no spark there would be an error somewhere.
All modules respond on Techstream. I went through them all individually just to satisfy myself.

I'm not familiar with the paperclip reset but the Battery has been disconnected for lengthy periods, would this not achieve the same?
I recall on my old BMW th advice was to disconnect the Battery and touch the Pos and Neg cables together, this would drain any capacitor charge in the ECUs. Seems drastic but many did it to no ill effect.

I have some Carb cleaner so the hillbilly method of spraying directly through the throttle will be conducted soon.

Linas.P · May 15

When you disconnect the sensors do they correctly trigger DTCs?

Yes crankshaft position sensor is under the alternator, so absolute beast to access, although I assume it could be disconnected from under the car

"Paperclip method" is just sure way to reset it in short period of time. In theory disconnecting the Battery should achieve the same results, maybe overnight, maybe in a day, maybe in 3 days, so it is not 100% reliable. Connecting positive and negative terminals indeed should shorten that period, but again it is not known how long exactly does it take. As such there is procedure to connect two pins on OBD2 port and it takes exactly 30 min (to be safe I set the timer to 45 min).

Note: this should be done carefully, because it is possible to damage the pins in the port and then you will lose access to diagnostic, correct way to do it (how Lexus does it), they have a plug that shorts those pins, so using correct diameter paperclip is another "hillbilly" method. Myself I got cheap OBD2 extension cable from amazon, cut it and connected the correct wires (costed me like £2.5).

1. with ignition on OFF, connect the two terminals

2. turn ignition OFF>ACC>ON (do not attempt to start the engine, so do not press the brakes)

3. leave for 30min + (make sure the Battery is charged or charging as if the Battery dies during the process it will fail)

4. turn ignition ON>OFF

5. remove the clip

chr15gb · May 15

Small update.

A gallon of carbon cleaner and it starts but only for a few seconds of course.

Throttle active test (ETCS) works. I'm on my own so I balanced my phone and took a video of it, I can see the flap open okay.

Also the fuel pressure rose to 1,500psi

Paperclip next, if I can find one

Linas.P · May 15

Okey, so your issue is fuel, you clearly have spark and air there. Fuel pressure rose because of high-pressure pump is camshaft driven, so if engine started for few seconds it pressurised the fuel.

You can try disconnecting fuel pressure sensor (it is awkward to reach behind the engine), but sometimes when they short out they may cause crank no-start issue and no DTC, whereas when they are disconnected car should start in "limp mode". Don't know any other issues why there would be no fuel, but no DTC. I suggest you do this before resetting the ECU, as if fuel pressure sensor is shorted the ECU reset may not work.

I know it doesn't quite make sense, considering that it seems you are still getting fuel pressure reported back, but for some people that was the issue that caused crank no-start.

Other idea, disconnect fuel hose in the engine bay (it has yellow plastic clip) and see if fuel is coming out, because if it is dry then maybe you have blocked line or leak somewhere, it is low pressure line, but still expect some fuel to spill out. Again I know this makes little sense considering you have reported fuel pressure, but without DTCs we can only guess what is going on.

chr15gb · May 15

I saw this video where the guy reaches the pressure sensor, it can be done by feel alone.
I'd agree its worth a shot even though the fault symptom isn't typical.
Doubt I'll get to look at it again until Friday so it will be preesure sensor, pull the yellow clipped fuel pipe then ECU reset with a paperclip.

Appreciate the help & suggestions.

Jon Dee · May 16

Sounds a bit like your injectors are not firing. If they were you should have gas in the cylinders by now, and at least get a few pops or bangs.

Cheers...

zoricib · May 16

If prior to your issue you started your car for a very short time (e.g. engine ran for around 30s), the engine could be flooded - this happened to me too. Start it over 4-5 times with your accelerator at the floor so it clears the unburnt petrol.

Linas.P · May 16

... but he got it started for few seconds with carb cleaner, so if flooded cylinders would have been an issue that should have long cleared now.

H3XME · May 16

29 minutes ago, zoricib said:

If prior to your issue you started your car for a very short time (e.g. engine ran for around 30s), the engine could be flooded - this happened to me too. Start it over 4-5 times with your accelerator at the floor so it clears the unburnt petrol.

Yeah, but he checked the plugs, if that was the case the spark plugs would be wet from fuel.

steve2006 · May 16

Given the previous radiator replacement and its location in respect to the crank pulley I would take a look at the CPS wiring loom and connector to the main loom as this may have been disturbed.

Unless the ECU receives a signal from the CPS the injectors will not fire.

IS300FSPORT · May 16

Apology not read the full thread.

My friend had a crank no start condition in a Toyota Auris petrol, recently turned out to be the crankshaft sensor. Have you tried replacement?

chr15gb · May 16

42 minutes ago, steve2006 said:

Given the previous radiator replacement and its location in respect to the crank pulley I would take a look at the CPS wiring loom and connector to the main loom as this may have been disturbed.

Unless the ECU receives a signal from the CPS the injectors will not fire.

I'm not sure which bit the CPS is but I was thinking similar.

I pulled the injector driver as that was all unplugged for the waterpump (over 200 miles of driving fine since).

I saw a youtube video, a guy condemned the driver as the base had power. Just pulled mine away from the engine block and I have 8.7v on the base plate.

Progress? Having 8.7v must be pulling the ECU and subsequently no injector pulse.

Now...about those error codes..nothing. wtf

chr15gb · May 16

Thinking about this a bit more.
The cranking, whilst working didn't seem particularly enthusiastic, it does crank but I thought it was a bit sluggish.

At IGN OFF the injector driver base plate is at 0v, Only with the ignition fully on does it see the 8.7v so most of the Battery voltage is going straight to ground through the injector driver base plate.

I've had a 12A charger connected whilst fiddling with Techstream and I had noticed it remaining at 12A for the whole duration. It normally steps down at it gets closer to a full charge.

I've bitten the bullet and bought a scrappy replacement for £25 on eBay. I'll be sure to sacrifice a chicken over the bonnet before starting up with the replacement driver installed.

If this works, I'm going to disconnect the MAF and a bunch of sensors to see if I can invoke some error codes.

The waterpump was changed more than 100 miles before the radiator went pop so that is at least 300 miles. Maybe coolant got in one of the plugs or some coolant crustiness grew after it dried out. A mystery.

Linas.P · May 16

It indeed sounds like electrical issue, mainly because of mysterious issues and no fault codes. No fault codes suggests something isn't communicating right with the ECU.

chr15gb · May 22

Not sure if a celebration is in order but the replacement Injector Driver has been fitted.
No change, just cranked but didn't start so after a few attempts, out with Techstream.

I had Errors!
B1421 and B1424
Both relate to the Solar panel. Air Con has always worked fine but in any case, not relevant here.

P12FF - Electric Driver Unit.
This is the Injector ECU I had just changed!

My heart sank, had I bought a dud? Was it mis-diagnosed?
The crank was different, the car seemed like it was trying to catch which it never did before.
I had a couple of half starts so persevered.

I assumed the engine was flooded due to so many attempted starts and after a while it felt like one cylinder caught, then two, then three, then four..thats enough, SEND IT!

Right foot down and up it stumbled and burst into life.
I held it at 3k rpm for about a minute, too scared to lift off in case it stalled.

Once at 3k rpm it seemed fine, juggled it between 3-5k rpm then tentatively bought it back down.
Settled okay and left it idling for about 30mins.

Turned it off, crossed my fingers and restarted, no problem at all.
Shut down and restarted at least a dozen times, all fine.

P12FF code has gone, only the Solar errors remain which I'm not bothered about.

More testing required before I venture it out on the road, sadly it needs fuel so I will need to shut down away from home.

Wish me luck 🙂

chr15gb · May 23

Success declared.

Still starting fine and took it for a spin. No faults, as if nothing had ever happened.

Huge thanks to all contributors to this, especially Linus. Hopefully this thread may provide some help for others whose IS250 uncharacteristically decides to not start.

Linas.P · May 23

Well done! This was a real headscratcher! I am slightly concerned that car can die like this and there was no code until after your replaced the faulty part... honestly diagnostics system has failed here. But win is a win!

P.S. B1421 and B1424 - doesn't mean anything, if it is dark outside (or if you in the garage which is not lit) then these will trigger for light sensor. You can literally put the flashlight next to the light sensor when running the diagnostics and they won't trigger.