E85 dying on (warm) start up

Zedebee

Lifer
North Hampshire
It’s happened to me twice now, once last weekend once this weekend, so not a one off. Both times it’s been the same. I’ve taken the car out for a decent drive with no problems. Got back, switched off and done something else for half a hour or so, maybe an hour. Then got back in the car and turn the key. It starts up fine, then immediately dies. I try to start it a few times and the same thing happens, foot off or on the gas makes no difference. Come back 10 minutes later and all is fine again. Any ideas what could be the problem? 3.0i auto.
 
Fuel evaporation?
Just guessing tbh but exactly the same as my old Capris used to do when they got hot.
In a fuel injection system the pressure should prevent this but maybe there’s an issue with holding pressure?
 
enuff_zed said:
Fuel evaporation?
Just guessing tbh but exactly the same as my old Capris used to do when they got hot.
In a fuel injection system the pressure should prevent this but maybe there’s an issue with holding pressure?
I thought maybe fueling. Any idea how to investigate?
 
Zedebee said:
enuff_zed said:
Fuel evaporation?
Just guessing tbh but exactly the same as my old Capris used to do when they got hot.
In a fuel injection system the pressure should prevent this but maybe there’s an issue with holding pressure?
I thought maybe fueling. Any idea how to investigate?
Without a pressure gauge? My only guess would be when it is warm undo the bleed valve on the end of the fuel rail to see if there is pressure there.
However, squirting fuel around a hot engine is not without risk!!!
 
j3nks79 said:
Could be a cam/crank sensor.
Worth giving it a scan to see if you have any stored codes.
Top marks j3nks, cam/crank sensor codes in abundance.
Is this one or multiple failing sensors? Where is it / are they?
 
Zedebee said:
j3nks79 said:
Could be a cam/crank sensor.
Worth giving it a scan to see if you have any stored codes.
Top marks j3nks, cam/crank sensor codes in abundance.
Is this one or multiple failing sensors? Where is it / are they?

What engine have you got?
 
Is it likely that all three have failed, or has one of them triggered a circuit. Any suggestions as to what order I should consider replacing them?
 
enuff_zed said:
j3nks79 said:
Crank sensor is below the starter motor. Not sure where the cam sensor is on that engine though.
Cam sensors are right beside the vanos solenoids.

Nice and easy to get to them. Start there and see what resistance you get on the with a multimeter. IIRC between 1.5-1.8 ohms.
Double check that as im going from my old brain lol
 
[ref]Zedebee[/ref], have you done any vanos work lately?
Really easy to get oil into the exhaust cam sensor plug.
 
enuff_zed said:
[ref]Zedebee[/ref], have you done any vanos work lately?
Really easy to get oil into the exhaust cam sensor plug.
Yes, did the VANOS refresh earlier in the.year, maybe 1000 miles since then. Sounds like a good shout to pull and clean the cam sensors before going any further.
 
j3nks79 said:
enuff_zed said:
j3nks79 said:
Crank sensor is below the starter motor. Not sure where the cam sensor is on that engine though.
Cam sensors are right beside the vanos solenoids.

Nice and easy to get to them. Start there and see what resistance you get on the with a multimeter. IIRC between 1.5-1.8 ohms.
Double check that as im going from my old brain lol
Good call, I’ll check the live values too if they are measured.
 
If you do change the sensors beware that aftermarket sensors don't always work properly, I changed my exhaust and intake with febi and the exhaust was fine but the intake caused the car to start every other attempt at cranking, a genuine bmw sensor solved this issue

If you want to test them you need to connect a multimetre and put a spanner across the removed sensor to see if resistance changes, 50s kid on YouTube explains this well
 
So I took out the exhaust sensor, gave the contacts a good clean, gave the sensor a good clean and cleaned the sensor cavity as best I could (access to the front of the engine is not the best), put it all back together and it seems to be working fine.

I’ll monitor the codes and if the problem reappears will move on to the next sensor along (inlet cam).

Thanks for your suggestions,
 
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