E30 Zone

my 320i touring started running funny on wednesday.
mid journey it started hunting and fooking about as i was trying to drive it, was ok full throttle, but holding a speed below 4000 rpm it was holding back and missing. wouldnt idle either. was having to knock it out of gear, left foot brake and keep it running with the pedal.
i checked it out after work yesterday. my first thought was the blue temp sender. but resistances seemed right according to the bosch inj systems book i have. checked out several other things at work to no avail.
i put it on the gas analyser.... it was sky high, over 9.99% co and hcs were 1300ppm! it was half six and i had to be sumwhere to be half an hour ago. so i twiddled the co adjustment down so it was running bout 2% and now 250ppm seems to run so much better now revs freeer. drove it this morning and it cuts out when cold now?????

any ideas?

rotor arm, distributer, coil, earthing.
Also check vacuum tube to fuel regulator

Check your TPS as it used by the DME (ECU) to sellect the correct map (idle, normal, WOT). A dirty airfilter soaked in oil will also make it run rich.

rotor and cap are good.
it just seemed like it was massively over fueling itself. been out to the shops in it, seems ok didnt cut out and ran fine.
im a little mistified bout it.........

checked out throttle pos sens. but not in depth, cus i dont think its that. guna check continuity of blue temp sender wires back to the ecu in the morning.

If the car was running using the WOT map it would massively over fuel. The blue temp sensor would increase the fueling but only really to the point where you would notice poor MPG and smell abit rich and only when hot, cold the car would drive normal. Even if it gave a resistance of 10kOhms (3kOhms is cold) DME disregard the signal as being beyond parameters and use a base setting. Having said this it is good practice to eliminate as many possibilties as possible. Keep us informed of your progress.

what does WOT stand for?? with out testicals??

Wide open throttle.

what does WOT stand for?? with out testicals??

lol

maxfield wrote:Wide open throttle.

now your just making shit up!

hi, peeps thought id update my thread a little...... since adjusting co down from sky high tio normal its been ok. replaced blue temp sender to not much avail.... seems better when cold.
the thing that foxing me at the moment is when warm/hot. just as your coasting along even at 2mph the idle is up and down between 800 and 1100 revs and sometimes stalls. but soon as you come to a stop itll rev to 1200 in its up and down cycle. then settle bang on 1000 as long as your stopped itll stay there, even if you rev it up, itll settle first time on 1000 revs. but stranger still........ say if your going down a hill youve come to a stop and the revs have settled..... you take your foot off the brake and roll forward itll start up and downing again then soon as youve stopped again itll settle 1000 revs. its not related to wether the brakes are on or off...... it doesnt have abs..... its not the tps..... thourghly checked it.....
my questions are; does the speedo sensor in the diff up to and inc. dash pod have any influence on the motronic system?? how else can the ecu know when the cars rolling?? and also what could it be doing???? wheres brianmooooooore????

murran wrote: my questions are; does the speedo sensor in the diff up to and inc. dash pod have any influence on the motronic system?? how else can the ecu know when the cars rolling?? and also what could it be doing???? wheres brianmooooooore????

This came up a few weeks ago, and the general consensus was that the road speed signal does have an effect on the motronic ECU.

so where does it link in to the system? and why? what? who? how? when?

Speed signal comes from the instrument cluster to the engine ECU through pin 14 of the C101 engine loom connector on a black/white wire.

so i should be seeing some sort of square wave with the oscilscope (spelt wrong) on that wire with the car on stands ticking over in first?
ill try that on monday after work...... cheers brian.

update...... havent checked out the pin check on that wire it seemed to stop doing what it was doing, couple of days after i posted that up. its been running fine. been to tdw2 over last weekend 300 miles there 300 miles back pulling my little trailer full of wheels and tyres, did bout 850 miles in total. drifted the arse off it. cained the shit out it round brawdy airfield. it ran like a swiss watch the whole time...... day after i got back on tuesday it started with another different running fault, ive never had a car with such a tempormental inj system, bosch you did a crappy job with the e30...... bring back k-jet is all i can say...... anyway its cutting out kangarooing all the time below 3500 rpm on anything but full throttle, hot or cold, but not all the time, can run fine for 5 mins or more. just feels like its a loose connection or sumurt, when it trys to cut out say round 2500 on part throttle the dash ign lights come on as it looses power, even tho the eng hasnt stopped, and the rev counter drops like its lost a feed or sumurt then suddenly its back.....started looking round it on saturday morning cus i was early for work for a change...... waggling wires as its tickingover touched this multiplug under the inlet manifold (think its for injector rail) and it cutout wouldnt restart found the plug full of rust and two wires broken just from me waggling them, anyway i completely chopped that plug out and joined them all by soldering them and shrinkwrapping them up. thought oh yeah ive got to the bottom of this...... but no 3/4 of the way home its started again...... been trying to drive it today and its worse!! and just been to the pub and its near undriveable in the low revs!!!......

please help cus im bout to sell it to the next person thatll give me a tenner for it and ill get another 87 golf gti. the most reliable car ive ever had, k-jet by the way.......

The touring you have is the most reliable car that you've ever owned. You've just not got it sorted yet!
The plug you've removed carries the ECU temp sender signal amongst others, so that could account for some of your problems.
Have you checked that you haven't split the big air hose between the AFM and throttle body?

if it were an air leak it would be doin it all the time...... this isnt..... goin to work and back yesterday and to work this morning it was fine...... but on the way home tonight after i picked my two boys up from nursery, it started doin what it was doin on sunday night...... the more it does it, the more im thinking crank sensor???????? at one particular junction it was doing it really badly and i could smell fuel so cant be fuel related. its almost like sumone has a switch and their switching the coil on and off as im trying to drive it....... if the crank sens. was breaking down what would the symtoms be????

my touring can be the most reliable car youve ever had....... all for a tenner.......

CPSs usually start off by being temperature sensitive when they start to fail. Engine starts from cold OK, starts to misfire a bit after it's warmed up progressing to completely cutting out and refusing to restart until it's been left for a while. There are always exceptions, however.
A failing CPS also tends to produce pulses at random times, so the cutting out is also likely to be accompanied by the odd backfire and blowback.
Has the main DME relay been changed?
You can try hooking up some small 12 volt bulbs or LEDs where you can see them. Connect one between coil + and earth, and one between the red/white wire off the DME relay and earth.

im guna order a crank sens cus that symptoms description sounds spot on to what its doin..... how much are they? if there more than 40 itll have to wait till i get paid on friday.

No idea what a new one costs! Plenty of second hand ones around.

s/h ones that prob no better than mine (potentially)! components like cps's id only buy new.....

B92510 IMPULSE SENSOR-MOTRONIC E30 320i Touring M20 01/88>12/91. Front Crank Fitment 32.50
does this sound right brian???

That's the one.
One of the good things about E30s is that there are very few parts which are always likely to be knackered on all examples, so there's rarely any reason to buy new (except rubber bits).

well brian fitted new crank sens...... its not that. was doin it all the way to work this morning, from when i started it to when i turned it off..... fitted new sens after work. seemed ok, then five mins into my 20 min journey home it started doin it but only for bout 3-4 mins then ran ok. but weirder still..... after fitting sens...... its started doin what it was doin few weeks ago idling up and down when rolling then settling when stopped, i havent touched anything else but crank sens!!!! and my oil level check light is on now...... where is the sens???? is it that single wire one thats just near the crank sens on the o/s of the engine, and the wire runs with the crank sens wire across the front of the engine?????

this is really putting me off e30s in general, i know vws and audis and never had stupid reaccouring running faults like this on any car ive had, and ive had bout 15 cars in my 8 years of driving. (im 26 btw).

Brianmoooore wrote: Has the main DME relay been changed?
You can try hooking up some small 12 volt bulbs or LEDs where you can see them. Connect one between coil + and earth, and one between the red/white wire off the DME relay and earth.

Also, has the throttle position switch been thoroughly checked?

Oil check (level sensor) is mounted in the top of the sump on the nearside, just below the alternator.

ill do the wire checks at the ecu relay and coil sometime tomora. yeah, tps is fine, least it was 3 weeks ago.....
ill have a check round the oil level sens tomorrow too. why is that level sens on? plenty of oil in it! i havent touched it!
damn cars we should all reject technology in all of its forms and revert back to a simple life working the land. what you think?

Has the TPS been checked electrically? Both switches inside it? Or just by listening for a click?
If the fault is intermittent, the tests might not be conclusive in any case, unless you happen to catch whatever it is at a time that it's prepared to co operate.
Oil level sensor: Check the connector is in properly (bolted to the alternator bracket). They sometimes get gunged up inside if oil changes are stretched to more than they should be.
Take it out (it's just above the oil level if the car is level, and the oil level not right at the top), fill a baked bean can with petrol and stand the sensor in the tin. Leave it for an hour, lift it up and let it drain. Repeat a few times, until gunge stops coming out.

yeah, checked tps with multimeter, just cus its clicking dont mean its working......
whatever it is ill get to the bottom for it somehow, its not guna beat me.... YEAH! you car outside, do you hear me your not guna beat me!!!
didnt get any service hist at all with my bus. what do you want for 265 quid?? ive changed my oil twice with 10/40 semi synth vw stuff since ive had it, but wouldnt be surprised if its full of gunk as you say, but today is the first time that level lights been on been on and straight after id been under the bonnet??

bri oil level light appears to have fixed itself....... was so annoyed by it idling up and down when rolling yesterday morning i got out and unplugged the diff sensor and it doesnt do it...... so thats that sort of fixed.
ive also worked out whats making cut out and fart about...... its just the why bit??
i think the idle valve is intermittently suddenly clicking wide open and shut again when running.... flooding the manifold with air before the maf has time to react and increase the fueling. it does do it on full throttle but you dont notice when driving cus the throttles already wide open so doesnt make any difference. it started doin it mid way home today so i got out and unplugged the idle valve and moved the stop screw to make it idle bout 1100 revs..... and it was fine. 7 times out of 10 if it starts doin it at that time on my way home itll keep doin it till i pull up outside home.

brian could you help me with the why bit?

Think you may have one of the few cases of an ICV that's failed electrically.
The ICV is (simplified) two opposing electric motors. If one motor intermittently fails, then the valve would either snap wide open or fully closed, depending on which winding was faulty.

I have a similar problem to your rolling idle problem but strangely mine is the opposite when rolling my idle is perfect(750 hot 900 cold or a/c on) and way too low when stationary. Montronic 1.3 has a vehicle speed signal input from the instrument cluster through c101 and into pin 29 of the DME but I can't find any information on why the hell it's there or what it's used for.

this sounds very similar to the issues I have been having with my 318i (posted as poor performance 318i) and I still haven't gotten to the bottom of it yet! CPS was going to be my next move, though I can't help feeling it's an underfueling problem/ It reacts very much like an air leak, but I have checked for those, so I will be really keen to find out what luck you have with the CPS. Good luck!