m20b27 Clerification Please. Sensor In Spark Plug?!?

[Fcknslo]

So I've been on here trying to find out some things about the purchase I just made. I have a 91 318is with a m20b27 swap. I've done numerous things to try and get the car to run and have came up empty handed. I just talked to someone that owns a european shop and he was telling me about how it could be numerous amounts of things. the car starts for 2 seconds then dies. He told me to rule out an intake leak completely, which almost a lot of you have said to give it a shot. He said that spark plug in cylinder 1 has some type of sensor in it to help tell the dme that there is spark, is that true? he said that often time speople replace them and forget about cylinder 1 spark plug. I have never heard of that but then again this is my first e30. he said my fuel lines can still be clogged, which doesnt make sense because I did tell him that I had a good fuel pressure rating. He said something about crank positioning sensor and told me that its very difficult to do which I find hard to beleive, Is there a way to properly test the cps myself? The man seemed very suspicious and seemed like he was taking advantage of my lack of knowledge when it came to e30 if someone can please tell me some things to look for in the no start or start then die area please let me know.

Some things about the car. its a b27 swap.
I checked fuel pressure and its consistant and I put a noid light to injector and it was pulsing till the car died. I pulled a spark plug to test for spark and am getting spark. I switched DME thinking it was bad and still came up empty handed.

I know this is a long post but if you have the time it would be greatly appreciated as I would like to have my e30 drivable this decade, thanks!

[nando]

the sensor goes on the #6 plug wire, not the #1, and it's not used at all on eta motors, only seta and M20B25s.

Further more, it's not neccesary at all to run, it functions as a crude way of timing the injectors to the cam phase. If you unhook it Motronic would just ignore it and run regular batched fire.

[Fcknslo]

So then what would be my general idea of fixing this problem? someone said the cold start valve could actually be the problem. and ideas?
thanks nando for reading it. greatly appreciated

[Fcknslo]

bump.

[kronus]

It starts for a bit, revs up, then dies? Unresponsive to throttle pedal?

If so, you should check the AFM for proper operation, or throw in a spare or borrowed known good one to eliminate it.

[Fcknslo]

it is not throttle responsive. checked for vacuum leaks and compression and it is in fantastic shape he says.
where is the afm located? sorry no bently here, yet.

[kronus]

The AFM is the Air-Flow Meter. It is on the other end of the intake boot from your throttle body (which is on the not-engine side of the intake manifold).

PM'd you a little something.

[Fcknslo]

Your a life saver. thanks man. I'll definitly look to see. is that a comon cause for start then die?

[kronus]

Your a life saver. thanks man. I'll definitly look to see. is that a comon cause for start then die?

Yes. If the AFM is malfunctioning, the ECU has no idea how much air is coming into the motor and cuts fuel (after starting it up via the cold-start injector and the idle control valve).

[Fcknslo]

are you talking on the mass air flow? I tested and it is working..

[kronus]

There is no MAF on e30s... it's technically called an AFM. Did you test resistance across it through the entire range of flap angles?

[Fcknslo]

not all but most yes

[kronus]

Test continuity between AFM leads and pins into the ECU. There's a pinout in the Bentley.

Your problem sounds exactly like what happens when the AFM is disconnected from the harness.

[Fcknslo]

I'm thinking about replacing the whole wiring harness on the fact that the one I have now is complete garbage. the guy that did the swap must have tried using the one that is originally in there and just hacked wires to get the b27 to get working and I'm more than positive that there is something wrong with it. will a b25 harness work with a b27 engine?
I've been told no but maybe cross refrence and just work with it or is it not even worth it.

[kronus]

It will work, but you will also need a B25 ECU and the various sensors that Motronic 1.3 needs, as well as a late-model AFM. Not worth it, I think.