motronic conversion nearly there, just wont run, help please

[mattyb]

more problems.

when i turn on the ignition the temp gauge goes up to red

also car wont start as theres no signal getting to the fuel pump relay to tell it to close. but if i link out the turminals 30 to 87 the pump runs. but car still wont sart if done when turning it over.

theres power at the coil so im asuming its sparking.

[Brianmoooore]

Sounds like you've got some of the C101 wires wrong. Gauge wire goes to full hot if the wire is earthed.

[mattyb]

had the cylender id sensor and crank position sensor crossed over.

so the old girl fires up now but then dies strait away could this be idle control valve. i will be very graetfull for help shes nearly there. please help me. thanks

[Speedtouch]

It could indeed be the ICV - does it hum when the ignition is on, and have you cleaned it out?

[Brianmoooore]

Sort the temperature gauge out. If you have that connected wrongly, the chances are something else is as well.

[mattyb]

temp gauge is sorted now. and icv does hum when ignition is on, im going to clean it out now. do i just spray carb cleaner in to it. thanks

[Brianmoooore]

temp gauge is sorted now.

And the problem was?? I can't sort this with just part information.

[mattyb]

could my problem be something to do with this little valve
as i dont have one on mine. my brake servo pipe goes strait on to the throtle body



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[mattyb]

sorry brian. i just pluged the new loom in to my brown temp sender which had two pins. went to bmw and the one that the computer said it was, only had one pin, so i bought it and fitted it. and temp gauge doesnt go up to red now. but the sod still wont run.

[Brianmoooore]

This is an old engine! I've never seen a two pin brown sensor. This type of sensor originally earthed through pin 20 of the C101, which is the reason for the brown wire that causes melt down problems on some conversions, as later looms use pin 20 for 12 volts live!
Can't remember if it's been said on this thread yet, but are the fuel pipes on the right way around?

[Speedtouch]

temp gauge is sorted now. and icv does hum when ignition is on, im going to clean it out now. do i just spray carb cleaner in to it. thanks

Yes, carb cleaner is good. The ECU must be at least partially working OK if the ICV is humming, so this is a good sign! Does the fuel pump whir away with the engine turning over?

You could post up a pic of your engine bay - someone may spot something amiss...

[mattyb]

speedtouch - i will get a pic of bay wen i finish work tomorow. and fuel pump definatly working had my hand on it when engine turned over by mate.

brianmoore - i have fuel pipe from the filter going to the fuel rail and the return coming off what looks like a pressure regulator. its mounted on top of fuel rail. the engine is an 84 car was a 323 but converted to alpina by sytners.

i really apreciate the help lads. its getting me down now. thanks

[Brianmoooore]

could my problem be something to do with this little valve
as i dont have one on mine. my brake servo pipe goes strait on to the throtle body



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This is the non return valve for the brake servo, and you certainly need one if you want brakes. There are two versions on E30's. The simple (later) one shown in your pic., and an earlier much more complicated one, that connects both to the throttle body and the air inlet pipe.
Can't see it stopping the engine starting ,though.
Your fuel lines are connected correctly.

[Brianmoooore]

Have you connected a 12 volt bulb from the + terminal of the ignition coil to earth, to check that power is present when the ignition is on?

[mattyb]

not a bulb but i checked it with a multimeter and there it 12 volts. it starts up revs to aboout 1500 then stalls. i seen a dizzt cap and rotor in th scrap yard tonight so will get that tomorow and see if i can get a non return valve too. thanks.

[Speedtouch]

Just a thought; do you know if your 380 ECU is good? Because this version was reknowned for blowing diodes in the idle control circuit.

[mattyb]

i dont know if it is. i willhave alook at the scrapy tomorow nite will your chip work in any 325 ecu, motronic 1.3. or will i need a 380. got a nice list of parts to get tomorow now. thanks maurice.

[Speedtouch]

It will work in any later Motronic 1.3 six-pot ECU, e.g., 172/173/380/381/179. The best to go for is the 172/173/179 type as these are most reliable.

[mattyb]

right thats what ill look for tomorow. will post up tomorow nite, hopefully with good news. thanks lads.

[mattyb]

right got a 172 ecu from scrappy today fitted it and it still does the same thing.

starts revs to about 1500 then down to 500ish for a second then dies.
if i screw out the throttle stop so it keeps the engine running but idle dances from 1800 down to about 1000. so i think there is a problem with the idle control valve.

[Banjo1981]

Might seem a daft thing but I've had a similar problem on mine after a recent head gasket change, are you sure you've plugged everything in? I've just pulled mine apart in a fit and found that I'd not connected the TPS!! Might be worth a look.

[mattyb]

just had a thought. it may be a stupid one though. could having the timing belt to tight cause my problem there is about 1cm of play in the belt, pushing it in toward pulleys and pulling it out towards me.

im clutching at straws now.

also there is two plugs next to the ecu on the engine loom that arnt pluged in. one is black and one is white, both with three wires. think one is aircon. not sure about the other.

one more thing, when im trying to start it and its stalling, the fumes in the yard burn my eyes.. not sure if this is evidence of something, but it never did this when i was using good old Ljet.

[Speedtouch]

Have you tried the 172 (320i) ECU with its standard chip, or with the C2 one?

1cm of play on the cambelt sounds OK to me - as long as you installed it correctly and the tensioner is good, all should be fine with that.

I know some people on here have had to connect a stray green wire running across the dashboard from the glovebox area to get their conversions to work, so it could be worth a look for this. IIRC, my 325i's had stray plugs next to the main ECU connector - perhaps you could post up a pic.

[Brianmoooore]

The only wires needed to be connected to the engine loom for the engine to run are the earth to the RH suspension turret, the red live to the battery terminal, the green ignition live, the green/purple out of the engine loom to power the fuel pump, and the black/yellow to the starter motor to start it. Everything else is just detail and instrumentation.

[e30topless]

I may be wrong but the white 5 pin relay should be on the left of the bunch ? I think the orange is 4 pin ?

[Brianmoooore]

I may be wrong but the white 5 pin relay should be on the left of the bunch ? I think the orange is 4 pin ?

The holders unclip easily, and can be put back in the wrong order, but the 5 pin relay should go into the socket that has a wire connected to the centre pin, and the 4 pin relay should go to the socket that has a green/purple wire connected to one pin.

[e30topless]

just a thought , worth checking, isn't the 5 pin the DME ?

[Brianmoooore]

The 5 pin is the DME. Worth checking; yes. If they are the wrong way around, everything will work as normal, except that the injectors won't be powered, IIRC.

[Speedtouch]

Holy smoke, this thread is the stuff of Sherlock Holmes!

[Brianmoooore]

I've become lost with this thread!
Answer these questions, even if they've been answered before:
Do you have power at the ignition coil + terminal with the ignition on and when cranking? Checked with a bulb between the + terminal and earth.
Do you have sparks? Checked by laying a spark plug on the rocker cover, connected to its lead, and cranking the engine. Should give a healthy spark once every two turns of the crank.
Does the fuel pump run when you crank the engine? Should be able to hear it.
Are the plug tips wet with fuel after a cranking session?

[mick_318is]

I thought that I would add my 2 cents worth just to clear up any confusion.

Matt bought this entire setup from me and it was working fine when it was removed from the car.

I supplied Matt with the

Inlet Manifold with injectors
throttle body
ICV
AFM
Airfilter Housing
TPS
CPS
Wiring Loom
ECU
Relays
Dizzy Cap
Rotor
Leads

The only thing I didn't include was the Oil Pressure Switch, which I couldn't remove from the block.

It all came from the J Reg 325 Touring I am breaking.

I was very careful when removing everything and only disconnected what I needed to in order to remove it from the car and get it packed.

Brian seeing that I didn't supply an Oil pressure switch it's not something silly like the ECU killing the engine becuase it thinks that the oil pressure is to low????

If not this Matt I would be triple checking all the wiring crossover between the old and new loom.

Mick

[Speedtouch]

It sounds to me as if the engine is hunting, possibly because of an over-rich cold start, hence the foul fumes. Check the blue temperature sensor is correctly connected, and of the right resistance; it's a negative temperature coefficient thermistor, which should be IIRC around 3300 Ohms cold and 600 Ohms hot.

If it's faulty, it fools the ECU into thinking the engine is always cold, giving an over-rich mixture.

[Brianmoooore]

ECU neither knows nor cares what the oil pressure is.
Has the round plug and socket under the inlet manifold, where the injector loom plugs into the main engine loom been checked out, especially under the lower rubber boot?

[mattyb]

blue sensor resistance. cold is 2862 ohms. hot unknown as engine wont run.

coil voltage 12.1 with ingnition on and 13 when turned over.

checked round plug for injector rail under both boots and all cables seem to be tight in there terminals.

had spark plug laid on top of rocker cover and definatly sparking

fuel pump definatly running

checked the three relays and orange and blue only have four pins and four cable conections on relay socket. white relay has five pins and has cables connected to all of them on relay socket.

spark plug tips arnt wet as engine starts but stalls straight away.

tried 172 ecu with standard chip in.

[mattyb]

i made a video so yous can hear the problem yourselves.



you can hear it rev up to bout 2500 then die down to bout 500 and try to keep running but stall.

im starting to think that its a weak mixture. the bits came from a low comp car mine is a high comp. i dont know if it could have something to do with it.