Engine STILL occasionally reving up on its own 'FIXED'

[Gibson]

Bastarding car has started doing it again and it is really getting on my tits this time! coolant tempt sensors (both) are brand new from bmw less than 3 months old so i dont think it is them. and i have cleaned and refitted the plug under the manifold 3 times! (is there an easy way to get this out further so i can get a good look inside it?)
so what else could it be? im sure it related to that damn sensor.

[Jay07]

Damn mate thats bad news!!! Ive been driving with my fingers crossed since my last post... luckily it hasn't stalled since, however i have to wait for the auto choke to do its thing before i pull away or it tends to stall when the choke cuts out. I had changed the orange sensor but according to brianM thats not what helped me as it only deals with the dash temp meter. Other than that i changed the drainage tube between the TB and rocker cover... That reminds me i have to check how much oil gets through to the air filter with the new tube.

If it happened again i was going to change the blue temp sensor... the one you've done...
I dunno, i've exhausted my knowledge... Hopefully someone will figure this out soon, it seem quite a common fault strange how its not tried and tested. Good luck mate!

[Gibson]

ok i have ordered ANOTHER blue temp sensor from BM and a throttle position sensor. gonna change these tommorow and see how it goes.

can anyone tell me where the wiring goes for the blue temp sensor. because i would like to do some continuity and resistance check on this?

Maybe the great man himself can tell me? (because it is a criminal offense to ask for him by name, he will asnwer only when he is ready)

[abelai]

It goes the connector under the inlet manifold

[abelai]

connector is C191 pin 1 BR/RD pin 2 BR (going to BR/OR) the BR/RD continues to pin 45 on the DME

[Brianmoooore]

connector is C191 pin 1 BR/RD pin 2 BR (going to BR/OR) the BR/RD continues to pin 45 on the DME

The problem with the C191 isn't necessarily the pins and their sockets - it's the wires that rot off the connector in the rubber boot under the connector, or even that the temp sensor signal is possibly affected by the 12 volts + on one of the pins, if there's enough salts in the water trapped there.

[liquid079]

ok i have ordered ANOTHER blue temp sensor from BM and a throttle position sensor. gonna change these tommorow and see how it goes.

can anyone tell me where the wiring goes for the blue temp sensor. because i would like to do some continuity and resistance check on this?

Maybe the great man himself can tell me? (because it is a criminal offense to ask for him by name, he will asnwer only when he is ready)

IF you want to check resistance at the ECU harness connector.

To find pin 45 undo screw on the back of the ecu plug.

Disconnect the plug from the ecu.

Undo two little screws where the wire cluster goes into the plug.

After removing the rubber seal you should be able to wiggle the white plastic bit that contains the pins out from the black casing enough to see the pin numbers written on the back of it(with good eyesight).

Then you can use your multimeter to check the resistance between pin 45 and ground.

Coolant temp 20 C- Resistance should be 2200-2700 Ohms(ish)

Coolant temp 80 C- Resistance should be 300-360 Ohms(ish)

Dunno if that makes any sense

[liquid079]

Oh and disconnect battery first.

Courtesy of Bentley manual.

[Brianmoooore]

Coolant temp 20 C- Resistance should be 2200-2700 Ohms(ish

You'll be looking at more like 4000 ohms at this time of year with the engine cold, unless your car lives in a heated garage.

[EOS]

I have a 318i as a daily driver and its doing the same thing, could mine be the same thing coolant temp sensor? Or is it only a 6 cyclinder fix thing lol.

Just to add my temp gauge in the car always seems to sit just under halfway, where as all my previous E30's have sat bang in the middle?

[Brianmoooore]

The faulty plug and socket (C191) is six cylinder only, but the blue temp sensor fault affects four and six pots equally.

[Jay07]

I HATE MY E30!!!!!!!!!!!!! This is so disheartening - one day im motoring along loving the car and the look/feel, and the next day (TODAY) Its starts dropping out again, with NO warning when i'm at a stand still idling (ie, lights, traffic) Theres no sign previous to the drop out - it just goes - almost cuts out - jumps then the revs go back up. WHAT THE FECK IS IT?? - I dont know any more to try and it makes driving this car HORRIBLE no matter how much i like it! - Im thinking of selling because i don't have the money to keep pushing into it blindly! It is my everyday car to and from work and i need it to be reliable.

Sorry for the rant people... I've just had enough of it. - Any ideas left?

[Gibson]

I HATE MY E30!!!!!!!!!!!!! This is so disheartening - one day im motoring along loving the car and the look/feel, and the next day (TODAY) Its starts dropping out again, with NO warning when i'm at a stand still idling (ie, lights, traffic) Theres no sign previous to the drop out - it just goes - almost cuts out - jumps then the revs go back up. WHAT THE FECK IS IT?? - I dont know any more to try and it makes driving this car HORRIBLE no matter how much i like it! - Im thinking of selling because i don't have the money to keep pushing into it blindly! It is my everyday car to and from work and i need it to be reliable.

Sorry for the rant people... I've just had enough of it. - Any ideas left?

I have come within minutes of scrapping mine aswell mate. its pissing me off no end! i am about to change the TPS. and have a look inside the rubber boot under the manifold as these are my main suspects. then its the ICV and if that fails im gonna tear it out in favour of M20b25 tried and tested engine!

is yours a 320 or a 325?

[abelai]

The C191 connector and wires can cause havoc to the car it's normally the lower half where the wires get damaged by the water that can become trapped by the boot.

[Brianmoooore]

Sorry for the rant people... I've just had enough of it. - Any ideas left?

Too long a thread to look back over! State what model and age the car is, and then list everything you've tried.

[Jay07]

Gibson, tbh i'm not going there yet with regards to switching out the engine(that just seems massive)... The problem i have is time to do the work, i dont have it any more as my job demands more from me - but i need to be mobile to work!

Hey Brian,
87' 320i

ICV has been changed
Cleaned out the TPS
New Air filter and drainage tube from RC
New Sparks
Replaced Fuel pump
Checked for air leaks
Cant think what else... Im dreading it but i might have to go back through this thread and make notes!

Its such a pain I want to keep as i've put a lot into it, it but its the family car, my Mum wont drive it anymore, and Pups has had enough! - Haven't given up yet!

[Brianmoooore]

'87 320 could be old or new management, unfortunately, and I don't know all that much about the early type.
Where is the distributor? Do you have two sensors on the bell housing? Any idea of the ECU number?
Don't see any mention of the injector loom plug and socket (under the inlet manifold) in your list, or of changing the DME relay.

[Jay07]

Morning - i'm sure the d-cap is on the front of the rocker cover area, i'm sure i changed the arm... it was a pain to get to
I don't know what you mean by bell housing but on an assumption, i have the blue and brown sensor. Please correct me if your referring to something else. Ive never checked the ecu number - could do that today.
RE: Injector loom plug - if that is the circular plug that screws closed then ive checked that - However looking in my haynes now you could be talking about something else (i know this isnt helping so i'll scan the pics in when i get a chance)
What is the DME relay?

[Jay07]

Not sure that this will help...

[abelai]

DME relay is on the n/s inner wing and supplies power to your DME(ecu) it should be one of three (fuel, O2 heater and DME)

[Gibson]

DME relay is on the n/s inner wing and supplies power to your DME(ecu) it should be one of three (fuel, O2 heater and DME)

How would this cause our revving up problem? but i may give it a go. the problem is causing everyone involved a massive headache.

[Jay07]

Gibson, dont know if you've seen this thread...

http://www.e30zone.net/modules.php?name ... 93#1023893

I'm going to do all i can to get this 100% sorted as everyone is trying to help! I've put a lot into the car too but i have to say if i cant sort it out soon i can't keep this car .... Let see what the weekend turns up!!

[Jay07]

So i got a chance to check out the injector plug before the rain came this morning! - It was surprisingly clean, there was no sign of corrosion at all! Now what?

[Brianmoooore]

Nice and clean under there, but it's under the bottom rubber boot (on the female half), that all the nasty surprises are found.

[Jay07]

I did check that Brian i remember you mentioning that before. It was a bit tight down there but i turned it over and had a look under the rubber and it was the same, clean no sign of trouble! I was almost hoping for some gunk but nothing to report. This is true stress!

[cro320]

I just searched for this problem cause it happened to me today.
Friend of mine deleted my LPG system out of car and made some wiring around DME relays, car worked fine and after 20 miles just suddenly revs on his own
I stopped, put in neutral but engine still revs from 2000-2500 rpm by itself. I cut it out, wait 15 seconds and everything semeed fine after. Anyone knows what this is?

[aceraf]

So i got a chance to check out the injector plug before the rain came this morning! - It was surprisingly clean, there was no sign of corrosion at all! Now what?

Does that plug just unscrew?

I checked the rubber boot on mine and it was filled with water (but wires seem fine) so i wanted to check the plug connections, but couldn't get it open. I didn't want to force it and break it.

[liquid079]

aceraf

Yea it just unscrews.

Might be a bit stubborn after all those years without disturbance. When I cleaned mine up and put it together I put sillicon around the plug to stop any water creaping underneath, it's in a vunerable position down there.

Dan.

[danman2k]

i had the same issue trying to unscrew, until i found a similar on in the engine bay below the windscreen drivers side. i practised with that and was then confident of doing problem one.

[aceraf]

aceraf

Yea it just unscrews.

Might be a bit stubborn after all those years without disturbance. When I cleaned mine up and put it together I put sillicon around the plug to stop any water creaping underneath, it's in a vunerable position down there.

Dan.

Just wanted to be sure. Rather ask than break it and leave it vulnerable to damage.

[Gibson]

mine is clean as a whistle and water free! So now what?

[jack148]

Any update on this thread??

[Jay07]

I've been lucky - One of my wheels got stuck on the car and i had to use a mallet to get it off - It was one of the front wheels - I was whacking it for a while - I think something moved, got de-blocked/released from the vibrations - I've not had the problem, since this day, not once. I don't recommend you all take out your hammers, it may have been a pure coincidence but i don't think so.

[liquid079]

So you fixed your car by hittting it repeatedly with a big mallet.. That's the sort of simple fix I like to hear about, top quality

[Gibson]

I havnt had a problem with mine since i rebuilt the rear axle..... so god knows what fixed it!