a question about the oil pressure swich

[parkin10]

on e30`s does the oil pressure swich not let the engine start up till the oil pressure is fully up?
mine`s a 325 on 89 year

[staley_turbo]

Shouldn't have any effect. Engine still runs when oil pressure light is on.

[parkin10]

i didnt think it worked that way
i am grabing at straws
it will not start on the button i cannot find any thing wrong with the engine sensors

[staley_turbo]

So you have good spark, good fuel and good compression? Only 3 things to make it run.

[parkin10]

great spark, good fuel pressure ,compression is 10.5 bar all 6 cyl
i wonder if the spark is late but how can it be

[town325i]

Have you done any work to the car that could of caused this

[parkin10]

the poor start up has always been a problem from when i got the car had the car 3years now
been chasing this no matter what i do this start up problem stays the same

[staley_turbo]

have you checked timing?

[hankino]

could it be over-fueling while cranking?

see this: http://www.e30zone.net/modules.php?name ... highlight=

if it tends to start ok hot, but not cold this could be the answer, and easy to check by bunging a resistor in place of the temp sensor.

the suggested loom is an oem fix and worked for me.

[parkin10]

timing is 13 degrees
poor start happens when both hot and cold
all ways starts on the button when its just been run hot or cold leave it some time and it hard to start again

[parkin10]

could it be over-fueling while cranking?

see this: http://www.e30zone.net/modules.php?name ... highlight=

if it tends to start ok hot, but not cold this could be the answer, and easy to check by bunging a resistor in place of the temp sensor.

the suggested loom is an oem fix and worked for me.

i did a little post on this thread

[hankino]

so you did - three years!

keep at it, mate, you'll crack it one day, or die - either way, job done!

[parkin10]

or i will get the motor right,repainted,new wheels
then crash it

[hankino]

lol
"yes, the old girl's going preeeetty sweet now....shiiiiiiiiiiiiiiit!"

[Supafly]

Have you checked the fuel lines going to the engine? also underneath the car by the (new?)fuel filter.

Also check the fuel pressure, the regulators look the same(IIRC) on the 2.0 and 2.5 but operate at different pressures. While you're there try pulling the vacuum pipe off the inlet and make sure there's no fuel or smell of fuel in there, if there is that points to the regulator again.

I had a nightmare with my previous 2.5 with a missfire that started after 2 minutes of running. Turned out it was dodgy one month old spark plugs, but I did loads of checks and loads of reading and loads of upgrading too. On the plus side the car ran beautifully after!

Good luck, hopefully get it sorted soon.

[parkin10]

thanks for all the replys
supafly you have given me advice before about my e30 s start up problems
about the fuel lines and pressure everything is 100%
engine sensors are good so is the wiring to the ecu
the only thing i have not had tested is the ecu it is the only thing left to do

[Supafly]

Have you had the co checked? sometimes people mess with the adjuster on the afm and it causes odd problems.

Can't think of much more, I'm clutching at straws myself now. If I think of anything else I'll post up.

Good luck

[parkin10]

i ran the car with the co set to 1.3 to 1.5 for 2 months start up was the same performance the same used more fuel---like i need that
then when it was mot time i set the co to 0.7 to 1.0 just the same but more mpg
if anything i think the ignition timing is late by the way it starts
problem with the pulse wheel?

[Fred555]

If you are really stuck you might find that it is the crimped splices in the engine wiring loom - they supply common ground, common +12V to sensors and or actuators and on some engine management systems there can even be an odd ECU supplied (no I don't know why some are made like that) voltage like 5 or 7 volts DC for some sensors.

Point being that the crimps even if they are tinned copper can and do corrode go green and then all the items receiving a common supply from that crimp do weird things as if it is ground splice then 0volts is no longer truly zero but the ECU getting it's 0v earth by being bolted down to metal and also tapped to an earth point under the dashboard means that things operate by a voltage offset equal to the volt drop created by the corroded splice so the sensor can be perfect but the reading the ECU will get will be off by the volt drop in the splice with actuators operating on a variable voltage things get worse still!!

Solution is to take out entire ECU and engine loom from car and remove all overall loom insulation, find all the splices cut out the crimps (do them all no matter how they look) and SOLDER the splices then use non adhesive loom tape (important point to use the right tape not insulating tape, also absolutely do not use self-amalgamating tape either - it seals in damp and causes problems later) to rewrap the entire wiring loom once you have tested the splices under a sufficient dummy load - needs to be perfect - you do not want to come back to one ever again - the soldering is difficult as the wires are generally green with verdegris so do not want to solder properly straight away - need a powerful soldering iron - over 50W - and lots of experience soldering - do not use plumbers solder - it has the wrong acidic flux.

Leaking windscreen washer pipe work or the bonnet mounted "T" pieces on BMW's can crack are classics for causing corroded splices - they leak often only when actually spraying the windshield.

Anyway I have done this to a couple of my cars (and other people's) over the years and it has always (so far) been successful in nailing those elusive problems that drift around and you can never quite nail down permanently - but you have got to make a perfect repair otherwise all hell can break loose and be a very good and experienced solderer of electronics - generally there are between 12-20 splices in the looms I have done - 3 were BMW looms.

It’s an epic job but it’s worth it - if you get it right otherwise absolutely don't touch!

[parkin10]

thanks fred
i was testing the engine loom only a couple of days ago
the cps wire has 3 wires in the connector black,yellow and a braided one
the black and yellow wire went straight to the ecu connector with no resistance
with the braided wire i found 5or6 earths on the ecu connector pins with no resistance in them
this is some thing i will look into
cheers

[Fred555]

CPS Crank Position sensor (if memory serves) is hall effect sensor some Motronic versions have nearby TDC (Top Dead Centre) or similar and sometimes they both have the same plug and socket style and sadists have been known to swap plugs for a joke to immobilise car but can in some setups of Motronic (somehow) still allow car to run - badly - somehow make certain the right one is connected to the right one - probably not a good idea to swap ”˜em over and see - if there are two adjacent devices that could have had their connections transposed trace the wiring with a ECU pin out to one of them - if there is only one there is no problem.

The braided one is a shield so interference and spurious signals do not get sent into the ECU the shield must be earthed to be fully effective but if you earth both ends a feedback loop can occur and put interference on the signal to the ECU it can be quite sensitive - meaning bloody temperamental - don’t know why some are and some are not - maybe it is to do with the age and condition of the sensor which then gives a weaker signal with age so the shielding becomes more critical for the ECU to hear the signal clearly? Anyhow the earth’s on one end of that braid are not really possible to diagnose with resistance reading because there is almost no current going through the braid to earth but disconnect the braid and you have a problem the braid should be connected to a common earth (might have its own clean ECU earth on some cars but if braid is obviously connected to 5-6 other earths than probably common earth) volt drop will not work either because no load to measure to cause a drop (therefore dummy load could be used - but I only use that to prove each soldered joint is perfect before I seal it up). That is why once I have found a couple of definitely iffy spices I just do the whole loom's splices as there are some things that are a practical impossibility to test.

You really need to do volt drop tests under load i.e. the operating load of the component at least - the current a multi meter supplies to measure resistance with will not be high enough to show every fault - resistance readings on looms only show up totally shot connections or wires but not more subtle deterioration - a micro or milliohm meter would show them up but it would be so sensitive that you would then need to work out the length and gauge of the cable to figure out what an acceptable resistance would be.

It’s the dirty battery terminals phenomenon voltage fine 12.6 headlights fine turn key to start and either a soleionoid click and then nothing or nothing and the lights go out (if you left them on) - Why?

The resistance that is present from the corroded battery terminal is low enough when there is only slight load so that a multi meter set to ohms (disconnect negative first otherwise reading will be meaningless) will measure almost no resistance - little more than the test leads themselves - but the instant the massive starter motor load is applied the current flowing rockets up & the effect of the resistance is multiplied by the load and the voltage cannot overcome the resistance of the corrosion on the battery terminal - but if you do a voltage drop test (set DCV) put one probe on top of battery post put other probe on battery terminal clamp (stab hard for good connection) you should see 0.00 or 0.02 volts voltage drop (differential) at most for a connection like that anymore and you have a problem 0.50 volts for an ECU loom wire end to end would be considered a massive amount - that is the only way to find loom faults in my experience - try it - and tell me how you get on.

[parkin10]

thanks again fred
the cps a new one
my basic problem is that the car does not start well and the torque is not that good at low rpm after 3000rpm it goes very well very noticeable difference in power deliverance
turn the key when cold it fires straight away but will only fire with the starter turning the engine let go of the key too soon and it stalls
when hot it just cranks some fires some then runs
once a blue moon when cold it will start on the button even when its frosty out,but only when the engine is cold

[Fred555]

Well if you have tested all the engine sensors with a recently calibrated and accurate digital multi meter (of good quality - the cheap ones give insane readings) at the sensor and then repeated the test from the ECU plug to see if there is any difference in readings to try and spot a faulty loom (although resistance tests are not the best way of finding these faults) then the thing everybody is told to do is do a major service i.e. an Inspection II in this case (and do it your self - garages always do as little as possible) I am not really in favour of that thinking because it masks the fault for a while and then it creeps up on you again as the newness of the service items wears off - but your symptoms do sound a bit like a clogged air filter - also have you checked the air flow meter - does the flap that moves bind anywhere through its arc of travel - that is a classic problem - BMW were stupid to fit the air door type of air flow meter, hot wire / hot film type are better in that they are generally dead or alive they don't fade away like the flap type BMW fitted - and give you hell in the fading away period - if it binds you can try sanding down the high spots on the side walls sometimes successful - or fit a new one.

The running with key held in start position is a clue as that gives extra starting enrichment automatically and overrides some engine sensor inputs having to be present to allow the engine to continue to run until the key is released then it relies on the sensor inputs again and the sensor created fault then comes back.

Run any fuel system cleaner thorough it recently - was it a good one? Masks fault but can sometimes really do the trick.

Can of oil system flush at next oil change - can give surprisingly good results.

Fuel injector to manifold "O" ring condition and general vacuum leaks - crushed / pinched misrouted vacuum hoses - total bastards to find.

If you are really certain it is nothing else it could well be the loom did a E30 4 cylinder 3 series loom (it had the Telefunken/ Siemens electronic ignition module on the front passenger inner wing) also had poor torque & various other problems no one could pin down, took out and soldered back together all the splices the torque was then phenomenal (for what the car was) the splices that supplied power to the ignition module /amplifier were in a terrible state - bright green verdegris corrosion the ones near the ECU in the loom section under the dash looked fine but were black inside - it was so successful all that extra power from the restored loom made the radiator (plastic top and bottom tanks) top hose stub blow clean off in the middle of winter ”“ all the extra power made more heat which stressed the old radiator to destruction this flooded the engine bay soaked the rebuilt loom (you try seeing how long antifreeze can take to finally dry out) and it ran very strangely until summer heat finally dried things out - but in the end it was definitely a success but the loom had to be done to nail it.

[parkin10]

if it was a faulty air flow meter i would have nailed it in 5 minutes of owning the car
fuel cleaner done!and then had the injectors out and cleaned in a ultra sound bath and spray tested reported in good working order
no intake leaks i made away to pressurize the intake manifold to 5 psi push some rag up the exhaust and then go listen for air leaks did not hear any!
the running on the starter,i would think its low on compression but with a hot engine,throttle open,plugs out 10.5 bar for 5 strokes of all 6 pistons good enough
fuel? i did once take the manifold off and sat it on the rocker cover to see what the injectors would do loads of fuel immediately on cranking
spark? well its got one i have wondered if its happening at the right time thats how it seems to me
my car does not have an ignition module the ecu is wired to the coil it has no distributor just a cap on the end of the camshaft no ajustments

[Fred555]

When you pressurised the intake system did the pressure hold steady at 5PSI and for how long bear in mind it is possible that some things could leak under vacuum only and not pressure - could pressurising have affected any vacuum components with a diaphragm or similar - fuel pressure regulator - what is the vacuum gauge reading of the engine when its running?

Fuel supply on cranking is not nessicarily the same as fuel while running depends on design of engine management system.

I know that you do not have a separate ignition amplifier module on a Motroninc car I was just giving that as an example but most RHD BMW's have more splices then LHD because having taken them apart they just extended the loom to reach the ignition switch being on the other side of the car etc. BMW just extended a LHD loom to make it RHD in addition to the splices that are present in any event to distribute common power and earth - in the Haynes manual for your car the page with the "Typical Motroninc system wiring diagram (1of2)" shows 11 splices - you in reality may have more or less then that you would need the wiring diagram for your chassis no.

To me it still sounds like the wiring loom the way the symptoms fluctuate in my experience is a classic sign - if you are certain you have eliminated everything else - do the entire wiring loom find all the splices and replace them all with solder - works for me. Good luck - tell me what happens next.

[Fred555]

Not a heat sesnsitive coil is it?

[parkin10]

[quote="Fred555"]Not a heat sesnsitive coil is it?[/quote
i would`nt know but its had 3 coils on
the original one a second hand one and a new one 4 weeks old proper bosch one at that!

[Fred555]

Coils can be difficult yours is a Bosch Motronic one which I suspect is different to the "fun" I once had with a Bosch TCI Ignition System (Siemens/Telefunken Module) Coil - the original coil that came with the car was a Bosch with black plastic body and said "Made in Germany" was retired by me (but kept) as the HT leads were open circuit and the coil windings resistance reading were too high - new leads and new identical coil (also Bosch, black body and Germany) problem sorted - years later different problem dead coil (shortly after doing all the wiring loom splices on that car probably the increased [and now correct] voltage supply that pushed it over the edge) - coil replaced with genuine BMW main dealer part (temporary availability problems meant I had to overpay at dealer) same amber plastic top this time no black body instead galvanised bare metal body said Bosch but this time it said not "Made in Germany" but "Made in Spain" - car immediately restarted but definitely lacked something then autumn came along and the misfiring started - coil windings resistance reading slightly too high (same readings on different test meters) put the original coil back in (that came with the car) as could not stand faffing about with the misfire any longer - now runs perfectly no misfire - still running perfectly on the original coil about four years later - went back to dealer with their coil, receipt, test specs and two test meters and got a £70 refund a month after I had bought it! Was also ready to take them on a test drive with one coil then the other to get a refund if necessary.

Although as the symptoms are the same with all the coils you have tried I guess that is not it - is an alarm or immobiliser tapped into the coil wiring to stop the car starting - connections can be bad or occasionally you will find that the car alarm wiring is not heavy / thick enough to drive the amperage requirement of some of the more potent electronic ignition coils (all BMW electronic ignition systems are considered very potent compared to other car makers ”“ only ones more powerful are the aftermarket ones used on American big blocks ”“ over 350 cubic inches) and as it loops back and forth to the alarm the voltage drop it causes can cause a design fault style of problem - could also be the alarm relay - if there is an alarm system at all that is.

Does the weather have any effect?

[parkin10]

one day the car let me down it turned out to be an old alarm cut the fuel pump off
removed it and soldered up the fuel pump wire and made good all the other wires

no the weather does not effect the start up,it can start up on the button on the coldest day ever

i have owned this car 3 years used it day to day for 2 years start up problems wouldent be so bad if it didnt have that flat spot at 2000-3000 rpm
as it happens it started perfectly this morning and then to come home from the supermarket i had to hold the key
i think its be like it a long time before i owned it and never fixed the car was in a very poor state of disrepair i have brought it on along way since

[bmwsport]

I had poor starting issues when i first got mine, after 2 years and many £££ replacing numerous parts all it turned out to be was the ignition timing. The distributor was set incorrectly and the idle screw was screwed nearly all the way in to compensate (Le jetronic management) hence having to always press the throttle on cold start up

It wasn't till i decided to refurb my rocker cover that i found when the timing was set correctly the engine rpm was really low so i loosened the idle screw and set it to 850rpm when warm and now it always starts on the button

[Fred555]

I don't think you can adjust the ignition timing on Motronic models, they have a rotor arm and distributor cap but that is installed on the end of the cam nearest the radiator and all it does is literally send the spark from the coil to the relevant HT lead there is no mechanical or vacuum advance mechanism or anything else like a distributor on those cars - daft point but are the HT leads in the correct positions and are they serviceable?

If you are certain you took out the alarm system in its entirety and are good at soldering then do the wiring loom splices you have nothing to lose.

Apart from weather temperature does dampness, humidity or sometimes damp rising up into the engine bay from beneath (if the car is parked on wet earth it works its way in) does any of that have an effect - or none whatsoever.

[parkin10]

bmwsport`s car has a different engine to mine and i think different motronic too

no the weather has no bearing on the start up
i gave it a good service 3 weeks ago and changed
coil
leads with cam position sensor
dizzy cap and rotor arm
crank sensor

and the alarm has been removed properly

with the compression good it seems to me like the spark is late
but what should the timing be on my car anyway so i can check it out? adjustable or not

[Fred555]

I think I saw an ignition timing map in an American "Robert Bentley" (publishers) service manual for the E30 but it was years ago - so don’t quote me on that - a good library (if there are any left!) might have one available on the shelf.

Is the seal ok that seals the back of the distributor from the engine?

[parkin10]

do you mean the black plastic dish behind the rotor arm? its there
and theres no oil leaks in inside the cam belt cover

[Fred555]

Yes - that plus (if memory serves) the big "O" ring seal behind it.

Do you mean to say that a full Inspection II and the leads coil, CPS, Rotor & Cap had absolutely no effect? Not even temporary effect?

What leads did you fit Dealer or other - neither is perfect the dealer ones have a cover that traps moisture and can cause misfires - some aftermarket ones have other problems - the leads are more a question of picking a problem you like more than an actual solution on the six cylinders.