Diagnositic machine for E30 M3, anyone got one/know of one ?

[rallyman1984]

I'm still having problems with my E30 M3.

Still stalling etc... and not starting etc...
Went upto our local garage who everyone(all other garages) in the local vacinity reckon has all the Diagnostic gear, but he cant get any of his 3/4/ machines to read my E30 M3.

Is there anyone who has the reletave equipment, or has had the error(s) on there E30 M3 Read.

It's driving me nuts !! Help me.

[jpboost]

no diagnostic gear on the e30 m3 I'm afraid.

Sorry.

[rallyman1984]

Poo

[Brianmoooore]

Can't you find a real mechanic who actually understands engines! The S14 is a very primitive engine electrically, by modern standards, and computerised diagnostic gear shouldn't be required by anyone who knows his job.

[Chris-W]

I had the exact same symptoms on an M3, and managed to fix it. Trouble is that it was about 10 years ago and my memory is failing me.

I've been trying to remember for the past few days. Will let you know if it comes to me!

[paddyvw]

what is the prob with it? mine is on the blink now but think it is fixed will know this eve? did you check on s14.net? there is a big post there bout a lad wit trouble getting his car going? my prob i think was my coil and the fuel relay also now it is flooded so iwl clean it out to day and i hope she will run? is your fuel pump working? have you spark?

[rallyman1984]

Well, the prob is, you'll be driving along, and it'll just cut-out/stall. But usually it'll start ok, other times it wont re-start at all.
Tryed by-passing the Fuel Relay when it wont start, and it makes no difference.
Had a wire on the coil, onto a light into the car, and light doesnt fail to go out.(when it stalls)

Anyway, brought it upto local Mechanic who has all the diagnostic gear, tryed 4/5 different machines, none will read it. Then, it stalled while he was looking at it, he suspected it was fuel related. Rigged up a fuel pressure tester/gauge and it sat at 3 bar all the time, and it then Failed to stall, so of course i still dont know if it is a pressure drop why it stalls/cuts out. It ran for near enough 2 hours with the fuel gauge on it, stayed at 3 bar, with me revving it, starting it, stopping it.
Then went to local BMS and got a fuel filter,still running fine. Then changed it last night, ran fine, left it ticking over for 5 mins, then as i left the unit, 500yrds and it stalled

Its also worth mentioning, that prior to it being a C*nt, it was always really rich when it was cold/on choke, and lumpy,(smelt really rich) then when it was warm, fine. But NOW, it runs fine from cold, no lumpyness, no really rich smell, but obviously it stalls.

Seems to stall more when its cold, but also when hot.

[Ant]

your TB gaskets ( proper name escapes me ) may be fubar dude, have you tested for air leaks at all ?

also, is yours a Cat ready car with 02 sensor ?

Agree with Brain, these are not complicated by anymeans, the e38 I've slaved over today has more electrics in the heater than the entire e30 engine loom

[Chris-W]

also, is yours a Cat ready car with 02 sensor ?

There's the mental nudge I needed - it was a faulty o2 sensor.

[Brianmoooore]

All you need to test an o2 sensor is a voltmeter. Signal should be switching between about 0V and 1V at a frequency of not less than 2 Hz. Faster the better.
Note: It's the frequency that's important, not the voltage.

[paddyvw]

i think it one or both your sensors on your bell houing ione is the fly wheel sender not sure bout the other. is it lumpy from cold? if so i think it is one of these as the dude on s14 had exact same prob and his sensors were fubared so changed them and all is good?

[rallyman1984]

UPDATE !!!!!


Checked the fuel pressure with a fuel pressure gauge today, and she sits at 3bar constant, even when it stalls. ! So it's not the pump nor the Relay at Fault.(as i have by-passed it before, and makes no difference)

I have also changed/checked the coil, it seems it's not this either.
HOWEVER, When she stalls/cuts out, it lets out a right hard "Knock" as if it is pre-igniting, and then the engine spins anti clockwise !!! and then stops. It even ran for a second backwards which is seriously harmful.

Now, I had a timing light on the No.1 Plug lead today(between dizzy and lead) and when it cut out, the timing light went out, so it is obviously killing the spark somehow, which is causing it to stall. It's worth mentioning, the Distributor cap and rotor arm look like new, and no obvious signs of arc'ing out or cracks in them.
I've also had a tester on the coil, and she sees 12Volts on both sides, even when she dies.

Had all three crank sensors (on rear of engine, clip in at scuttle panel also)
out and cleaned them, but dont know if they could be faulty. ?? Anyway of testing them ? Remember, it can run fine for ages, and sometimes when it trys to die, if you rev it up, it stops it dieing. Are they expensive ?

Remember, the car can run fine for AGES, then just suddenly dies, trys to spin backwards and pre-ignite (i think) It's really REALLY annoying, as i'm really trying to figure it out, but no one has any diagnostic gear for an E30 M3

Any Ideas ? If you could let me know your thoughts it'd be most most appreciated.

Brian, not checked the O2 Sensor, the car does have a cat on it.
Also, it did used to run really lumpy when cold, but seems to have stopped doing that now, and runs fine from cold, but has this terrible problem of stalling/cutting out/pre-igniting.

[rallyman1984]

Oh Oh Oh, Also, changed the DME relay today as when i took it off and shook it, it seemed like it rattled a little, changed it for another, still made no difference !

[maxfield]

Where abouts are you based surely theres a speacialist close by?

[rallyman1984]

Manchester

[tobias]

where abouts in manchester???

[Brianmoooore]

The ECU fires a spark plug when the crank position sensor tells it to. A failing CPS could give off a burst of signals between its correct firing points as it fails, giving sparks at random incorrect times. This could account for the backward running as it stalls.
Oscilloscope hooked up to the CPS would be interesting, but it would have to remain hooked up until the trouble occurs.

[kdw215b]

Have you checked the ECU, sounds like some water may have got into it. Which is quite common.

[DaleR]

I recon its a dry joint in the ECU as I said in a previous thread.

[rallyman1984]

Dale, How could i find this ??

Be Detailed, as i'm fairly mechanicly minded, but aint no electrictian.

Or do you mean i need to replace the ECU ?

[rallyman1984]

Also, there are three Sensors, all pointing at the flywheel , at the rear of the engine, i take it all three control the timing etc.... E.g Like having three crank position sensors ?

There are two at the bottom, both silver and shiny, part no's are both the same on them two :- 1 708 610 and then there is a black sensor further up, i'm asuming that is the actual CPS ?

On a positive note, i've changed my headlamps to the smiley ones, and fixed the dodgy connection on my Front Fog light, neither of which help it run tho.

DALE R, Giving the ECU a slight tap doesnt seem to acheive anything, i think it was all in my mind, as it seems to make no difference.

[rallyman1984]

Is there anyway of testing the CPS before i go and get a new one ?

Thr black one is approx Ԛ£20 from Main Stealer, i dont think EURO car parts do one,
and the two other sensors (Pulse generators?) are about Ԛ£56 each from Main Stealer.

The small black one (1 287 784) I am assuming is the main Crank Sensor,
and the other two larger ones (1 708 610) are pulse generators. I could end up replacing all three !

[Brianmoooore]

Is there anyway of testing the CPS before i go and get a new one ?

Thr black one is approx Ԛ£20 from Main Stealer, i dont think EURO car parts do one,
and the two other sensors (Pulse generators?) are about Ԛ£56 each from Main Stealer.

The small black one (1 287 784) I am assuming is the main Crank Sensor,
and the other two larger ones (1 708 610) are pulse generators. I could end up replacing all three !

Apart from monioring its output with an oscilliscope, as I said above, they are often temperature sensitive when they fail.
Can of refrigerant spray might just show it up.