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ian doherty 
Newbie 
Joined: 12-March-2005 Location: IRELAND Status: Offline Points: 34 |
 Topic: e28 -535iPosted: 19-April-2005 at 19:58 |
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any body got an idea, to what would b causing my car to run a little off tune,when starting from cold,its not big time bad,but to me its anoying,espically after spending several hundred on engine+fuel filter+100% service,and the last thing that i was advised that would cure it was full set bmw spark plug leads,over all its better,but not the chesty cold start up!!!!!!
 HELP!!! ; ;
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Doive
Really Senior Member II 
Joined: 09-February-2005 Location: Clinging to a turbine, Hexham Status: Offline Points: 1212 |
Posted: 20-April-2005 at 07:46 |
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Could it be a slightly blocked injector? The 535 is the M30, while my 525e is the M20 so I can't offer anything other than that mate I'm afraid. Mine is very hesitant when starting as well, it needs a bit of throttle and then the revs held around 1000rpm for a couple of seconds or else it stalls. My thoughts are that this could well be the idle speed control valve playing up? If you boot the throttle on mine, it hesitates for a second, the revs drop then it picks up with a satisfying roar. When the throttle is released, the revs fall away and the car tries to stall before picking back up again. So my thoughts were the idle valve or slightly clogged injector. Does yours do any of the above?
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1987 BMW 525e Lux Auto (sadly deceased)
Get Firefox - Ditch Hopeless Inertnet Exploder www.doive.co.uk 
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Brucey
Really Senior Member II
Joined: 07-March-2004 Location: United Kingdom Status: Offline Points: 744 |
Posted: 20-April-2005 at 13:28 |
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you need to find out if it is running rich or lean to diagnose. A sticky cold start valve would do it- the car may start without this valve operational (all the other injectors go double-duty on cranking, so there is lots of fuel to start with regardless....) but run badly (lean) until the engine has run for about half a minute. A duff 'thermotime switch' will also do the same thing- this is the gadget that controls the cold start valve. Below 40C (or something) it switches 'closed' for about half a minute when it is is powered up, and this controls the cold start valve. Check out the haynes manual for trouble-shooting. If both of these check out Ok then worry about fouled spark plugs from short runs, &/or low compression, or water in the fuel. cheers
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~~~~~~~ Brucey ~~~~~~ |
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ian doherty
Newbie
Joined: 12-March-2005 Location: IRELAND Status: Offline Points: 34 |
Posted: 21-April-2005 at 19:18 |
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doive my m30 is more or less the same the idle goes that low the red instrument lights come on and if i dident gas it i NO it would conk out in most cases,and brucey as u said it does stablise in about a min,but whatever is causing this i believe,is playing a slight role in the engine management coldorhot,i think this because theres just something wrong with the smooth running of this engine,its as if its running on 5 1/2 cylinders,this might sound weird but thers something not sending or reciving a signal in engine,like quiet often when i press the clutch to stop at lights etc....the engine will die,restart ok now,but before i started my marathon of works to engine it took several mins to restart !! I would deem my machanic nos his stuff, he was sure that when i collected the car from him it needed a set of leads that would take up 2 a week to come,it came and i fitted them,it was still the same,he said that 1 of the plugs must b oily or wet and to take each one out until i get it,clean it up like new and" bobs your uncle" HOPEFULLY...............but is there a machine that would point out the cold start or thermotime switch being faulty,like a creptontuner,or would i need to give car&blank cheuque to bmw dealers !!!! or just get the parts u wrote about brucey or can u check there operation &nb sp; P.S............thanks doive&brucey
Edited by ian doherty |
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Doive
Really Senior Member II
Joined: 09-February-2005 Location: Clinging to a turbine, Hexham Status: Offline Points: 1212 |
Posted: 21-April-2005 at 20:18 |
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I know for a fact that my idle speed control valve is sticky and needs
replaced, but current bank account won't allow such things! My car does
strange stuff sometimes as well - if started from cold and allowed to
idle, the alternator, oil pressure and brake warning lights will all
stay on for a few seconds before going out. When these go out the
engine idle changes and becomes slightly co****r, like something in the
ECU has switched. It still idles fine but there is a definite change in
tone.
If the engine is revved when cold (gently of course) and the throttle fully released, it will almost stop before picking up again, stop again, pick up again and finally stop as if it is struggling to hold an idle - been told this is probably the idle control valve. I need to hold her on a trailing throttle to keep the engine spinning. To be honest mate from what I remember an idle speed valve isn't that pricey so you may be as well replacing it - they all go eventually. On the M20 replacement is a two minute job. Unclip wiring, release rubber retaining collar, gently pull from intake hoses and fit new one. Would assume a similar sequence for the M30. Afraid I know nothing about the thermal switch. |
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1987 BMW 525e Lux Auto (sadly deceased)
Get Firefox - Ditch Hopeless Inertnet Exploder www.doive.co.uk
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Doive
Really Senior Member II
Joined: 09-February-2005 Location: Clinging to a turbine, Hexham Status: Offline Points: 1212 |
Posted: 21-April-2005 at 20:21 |
I do not believe the software does not allow the word 'corser' (sp), meaning less smooth, to be written on the forum for fear of including certain words. |
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1987 BMW 525e Lux Auto (sadly deceased)
Get Firefox - Ditch Hopeless Inertnet Exploder www.doive.co.uk
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ian doherty
Newbie
Joined: 12-March-2005 Location: IRELAND Status: Offline Points: 34 |
Posted: 23-April-2005 at 19:58 |
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any ideas guys how or what i could use to easily"i hope"test the operation of the injectors in my "m30"..................ALSO the fan that blows the heat into the car is on its last legs,does a motor out of any other later bimmers, the same type as the e28 "535i" 1988.,.,.,
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Brucey
Really Senior Member II
Joined: 07-March-2004 Location: United Kingdom Status: Offline Points: 744 |
Posted: 24-April-2005 at 10:32 |
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there are at least two different types of fan motor. If it only does full speed, the transistor is probably blown. If its just erratic even on 'full' then a dodgy connection or very worn brushes are possible. The other thing is that all kinds of rubbish can get into the fan housing and foul the fan. It'd be a good idea to get in there and see what it all looks like before condemning the thing. cheers
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~~~~~~~ Brucey ~~~~~~ |
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ian doherty
Newbie
Joined: 12-March-2005 Location: IRELAND Status: Offline Points: 34 |
Posted: 24-April-2005 at 19:15 |
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i already had the fan out.cleaned in and around it,lubricated,then i put back in,it was slightly better,but still VERY noisey.It comes on strong on high speed,then it noticeably gets slower to burn out!!!
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Doive
Really Senior Member II
Joined: 09-February-2005 Location: Clinging to a turbine, Hexham Status: Offline Points: 1212 |
Posted: 24-April-2005 at 20:15 |
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Sounds like the brushes have died. When badly worn they burn out and
fail to transmit sufficient current to the commutator to keep the motor
spinning. I don't know if those are selaed for life units or whether
the brushes are accessible and replaceable, may be cheaper than getting
a whole new unit.
For the injectors I have heard one possible method is to take each out in turn and crank the engine for a couple of seconds with the injector in a glass jar and measure the average flow rate per second. This should give you a rough idea of how much petrol each injector is flowing per second, and allow you to identify any lazy or erratic ones. Never tried this myself, but been told it works. Would suggest disconnecting your coil first to prevent the engine firing on five cylinders! |
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1987 BMW 525e Lux Auto (sadly deceased)
Get Firefox - Ditch Hopeless Inertnet Exploder www.doive.co.uk
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ian doherty
Newbie
Joined: 12-March-2005 Location: IRELAND Status: Offline Points: 34 |
Posted: 25-April-2005 at 19:06 |
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going to bmw breakers tomorow ,u think i am silly getting second hand fan,if i can find one! was reading hynes manual, it talked about listening to injectors clicking with a stehacope?or screwdriver,,,alough i tried the screwdriver and could here nought!! but your idea doive is similar to taking out the cold start injector(same wavelength) which i hope to do in next few days,I THINK my problem is, i dont have enough time to drive or take care of the old lady and the previous owner done me no favours either by neglecting VERY VITAL issues the car had! Help me on this 1==there is 2 leads going from 2 plugs that click together,out the other end these leads r going to the gearbox"for ignition timing??",...now,these plugs,it seems r supposed 2 b connected through a purpose made bracket,from about cam cover to injection manafold at rear of engine,beneath wiper motor,,,,,i found these while tring to get engine started "hot at the time" i wiggled at these plugs and engine started,and this has worked several times since<<<<Any ideas or thoughts,previous owner obiviously had done this,why??? how do i rectifie concidering why it was done |
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Doive
Really Senior Member II
Joined: 09-February-2005 Location: Clinging to a turbine, Hexham Status: Offline Points: 1212 |
Posted: 25-April-2005 at 21:00 |
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I have no idea what such plugs would be for, as for the ignition timing
issue the gearbox (auto I assume) would have no bearing on what the
timing is doing. I really can't say what such leads are or what their
purpose is. The fact they have been getting warm whilst starting the
car would suggest they are handling some hefty current or else your
engine to body earth is not a happy bunny and the engine is earthing
through these wires - check for corrosion around the wing earth mount.
You ask how to rectify these wiring mods - do you know exactly why
these were done to the car?
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1987 BMW 525e Lux Auto (sadly deceased)
Get Firefox - Ditch Hopeless Inertnet Exploder www.doive.co.uk
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M3AG
Really Senior Member II
7 series & e36 m3 registrar! (Madness) Joined: 17-October-2002 Location: Good Old Hertfordshire Status: Offline Points: 1644 |
Posted: 26-April-2005 at 09:53 |
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those two plugs are the pulse sensors for the ECU, one controls starting the other controls things like idle etc, if one fails it stops it from doing either the above! Still available from the dealer (�48 ea), and easy to fit, but give them a clean first, as it sounds like you have a bad connection. Clean the plug end with some electrical cleaner the other end plugs into the bellhousing, remove them, clean and put back, see if this makes any difference?
The bracket can be had from a breaker, and it fits between the inlet manifold and the head/cam cover, it has holes in that allow the two connectors to meet! Again easy re-fit, two bolts and it's done. But whatever you do, don't get them mixed up! Edited by M3AG |
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e28 -535i
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Doive wrote: