Other manufacturers - Chat and technical area > BMW Car Parts Forum
523iA E39 gutless when started from hot
stan_deezy:
Have you had the fault codes read?
This could save you a small fortune, although the air flow meter can often have a fault and not show this on the codes, but it can sometimes.
The fact that it is doing this when hot suggests the ECU is seeing the wrong expected temperature and loading fuel into the engine; so swap out the coolant temp sensor (the one for the ECU, not the dash gauge).
.............................................................
Josh Tildesley:
quote:Originally posted by stan_deezy
Have you had the fault codes read?
This could save you a small fortune, although the air flow meter can often have a fault and not show this on the codes, but it can sometimes.
The fact that it is doing this when hot suggests the ECU is seeing the wrong expected temperature and loading fuel into the engine; so swap out the coolant temp sensor (the one for the ECU, not the dash gauge).
.............................................................
Thanks for the post, Stan.
Well, having run the car for the best part of a week with no problem with the MAF sensor disconnected and then for the symptoms to return tends to indicate that the MAF isn't to blame. I didn't realise that there was a separate sensor for the guage. This could explain it because, as you say, if it's just happening when the system is warm....
I took a trip yesterday evening to a store in Leeds, about 25 miles away. I needed some fuel when I set off so I drove about 5 miles to the filling station. At this point the car was performing and responding fine. As soon as I started up after refuelling, the problem was straight there.
The odd thing was, after I'd gutlessly crept along most of the way to Leeds, stalling at most junctions, I got to the last roundabout on my journey and the car sprung back into life as if nothing had happened. It remained fine for the whole of the return journey and another short journey I made later that night!
I am having the codes read next week whilst having my brake pads renewed so I'll know better what sensors could be malfunctioning then but I'll definitely be looking for the temperature sensor for the ECU and perhaps the Cam Postion Sensor too... I'll update here when I have some more info because if someone else encounters the same problem, this thread may help them. [:)]
Thanks,
JT
-------------------------------------------------
Two wrongs don't make a right but three lefts do.
jes x:
Exact same problem with my 99 318se, eg - start the car in the morning from cold and it runs great. Drive for example to the supermarket which is 15 minutes away and park up and go shopping. 30 minutes later return to car and start engine and it sounds like it running on 3 cylinders, very uneven idle and cuts out when I stop. 10 minutes later of drining and its running perfect again !!!
replaced-
both lambda sensors
MAF
help.............
fkhatib:
Hi Josh !
I am almost having similar problem in my E39 2002 car, I would like to know if you've been able to solve the problem out.
Cheers.
Firas
Josh Tildesley:
Hello there,
I've been struggling with a problem for a while now with my E39:
Fine from cold - bags of power.
Drive somewhere, stop for half an hour or so, start engine - gutless.
It feels like the management module has dropped into safe mode.
I initially thought it was the MAF sensor so I unplugged it. The car seemed to be running fine for about a week but then the other day, it did it again - this time with the MAF unplugged!
It also stalls at the most inconvenient times, i.e. while turning right! [:0] Scary stuff.
Roundabouts don't exactly have me screaming with glee either...
What else could it be? Cam Position Sensor? Fuel pump? Temperature sensor?
It wasn't something that got gradually worse, it just did it one day and has done ever since. Very frustrating because when she's on song, she's a flying machine as much as a 523i auto can be!!
I'm lost at this point and don't want to just replace sensors willy-nilly until I find out which one it was with my wallet a grand lighter!
I'm guessing the problem must be electrical in nature rather than mechanical as I reckon if the problem was mechanical, it would happen all the time - not just from a hot start.
Any suggestions would be very useful.
BTW, my E39 has just had its oil service done by an independent BMW specialist and has 5 green lights on the display.
Thanks,
JT
-------------------------------------
Two wrongs don't make a right but three lefts do.
Navigation
[0] Message Index
[#] Next page
Go to full version