Issue with a S50b32 compact

[HairyScreech]

Got an S50b32 powered compact here that I am in the process of wiring up for a friend, however at the moment all I can get is infinite cranking.
I think its one of a couple of obvious things but before I go spend another afternoon on it I thought it would be best to get a second opinion from here.
as far as i can tell all the EWS 2 is in an working as normal, the reader, key, module and ecu are matched, I have tried both the M3 and the compact GMIV with the same results for both, with the key reader unpluged I get nothing, not even cranking. With it plugged in all is normal with cranking and fuel pumps running briefly and then continuous after cranking.

The two extra wires on the 12 pin plug are not currently connected but i am led to believe these are superfluous.

The relevant DME relays seem to be kicking in but it is hard to tell.

Dash does appear to be dead-ish, ignition/battery light comes on and the dash illuminates but that all i get from it, the rev counter doesn't flick on cranking, the LCD is black and the fuel gauge is OS. I think there may be an issue here but I did not see it working in the M3 so I don't know if this is new or not. Certainly I can't find any info to say the dash is not compatible.

The M3 carbiolet donor did have a RM4 but this is just for the windows right? It also had an OBC but I doubt that has anything to do with it, after all the symptom is the same with either General Module and one is M3 (windows and OBC) and the other is compact (GMIV LOW = bugger all not even a plug for it)

Did not get a chance to check for fuel and spark today, that's the first places I am going to go looking. There is a possibility that the fuel pipes are on backwards (stranger things have happened).

The X20 plug has not been modified from the 318ti that it began life as, I was told this would be fine for now as none of the critical functions moved around in the plug. Personally I am not so sure.

Any thing else I should add to the bug hunt?

[jmc330i]

The X20 plug has not been modified from the 318ti that it began life as, I was told this would be fine for now as none of the critical functions moved around in the plug. Personally I am not so sure.

I was under the impression that the X20 wiring should be the same - I've got a 318ti loom that I was going to check against my wiring charts for the S50B30 (1995 with EWS) but I haven't had the chance yet.
Only thing is, the EWS module from my 318ti says EWS 3 rather than the EWS 2 from the S50. As above, I've not started looking into yet, but I can't see the wiring being too much different if at all. I wasn't expecting EWS 3 and don't really know what differences there are between 2 and 3.


I did have an issue with my S50 not starting, where it would just crank and crank but not even attempt to fire. It turned out to be battery related. The battery in question would start my M20 E30 and my diesel 306 without problems but would only crank the S50.
After half a day of rechecking all my wiring, I fitted the battery from my 325i and the S50 fired, albeit roughly. I took the plugs out and cleaned them (very dirty from all the cranking) and it fired first turn and ran sweet as. Refitted the original battery and got nothing but cranking. I had checked for a spark with the original battery and there was one, but with the newer battery fitted, the spark was noticeably stronger.
I was later told that the coil packs on the S50 need decent power to spark properly. Even though the duff battery was spinning it over fine, the coils weren't producing a strong enough spark.

Once you've checked the fuel lines are the right way round, it might be worth trying a different battery before like me, you spend hours tracing a wiring problem that isn't there

[HairyScreech]

Dae just rang me to say he swapped the fuel lines and its running.
Dash is still out though.

[HairyScreech]

To add an update on this. I have been down to see the car myself now and although it is running its only really just running.

The issue with the dash has been solved by a loose plug.
The fuel pumps have been swapped to the m3 pump.
All earths have been checked.
The EWS is working 100% fine.

Trouble is the car seems to have a chronic misfire, sounds like its running on 4 and dies if the throttle is closed.
I am personally worried that there is an issue with the valve timing or the vanos, (read paranoid) even though it was checked 3 times by 2 different people, the misfire combined with a bit of coughing out the inlet leads me to this.

However i did notice that the front three branches of the exhaust were too hot to touch after only 1 minute of running while the rear bank were still cold to the touch.
Which way around should the lambda sensors be plugged (lead A to front bank and lead B to rear?)

Biggest issue is we cant get the snap-on diagnostic machine to talk to it, doesn't want to connect which is a pain and going to make life harder im sure.

Anything thats common that i should go looking for?

[jmc330i]

The rough running and coughing through the inlet happened on mine also.
Have the plugs out and give them a good clean, its amazing how fouled up mine got after 30mins of trying to start (you can also check for a spark while they are out).
I had all sorts of horrible thoughts (timing issue, fucked engine etc etc) when mine was running like this, but as I said above, a decent battery and cleaned plugs had her running sweet as - always start with the simple stuff.

I'm fairly sure the lambda sensors are plugged 1-3 A and 4-6 B, but I can't get my notes to double check that.

[HairyScreech]

Well if your thinking on the lambda is a=1-3 and b=4-6 then that matches what i thought. they were plugged in the otherway around (wasn't me) so that explains the massively fouled plugs and temperature difference.

have cleaned the plugs and we are up to a steady 5 cylinders, still a little off on number 6 but im suspecting the coil so I will swap two over and see if it moves the misfire to another cylinder.

Interesting to hear you also had coughing back up the inlet, that's pretty unusual on modern stuff (provided nothingness out of whack), the timing at cranking speed must be pretty aggressive on these lumps.

[HairyScreech]

update - found the plugs for number 4 and number 6 were reversed, solved this and cleared out the keep alive memory on the ecu - result one car running properly.

For anyone else having the same issues lambda plug a is the front bank.