MembersPage/MattiasSandgren/PeppesBmw (2006-03-16 04:43:08)

BMW E30 323 with M20B25


The engine


Ignition trouble

Measurements on ignition parts were good:

We had no significant 60-2 trigger wheel errors, the only time was during cranking where we got 3-4 wheel errors and then everything was alright.

First step during ignition setup tonight was to connect the coils and set the ignition order right. We layed the spark plugs connected on the valve cover and fired each coil and could clearly see the spark on the two connected plugs of each coil - and then set the ignition order accordingly. We then mounted the ignition plugs and started with no fuel, and strobed cyl 1 and saw that it was accurate at 10 degrees before TDC, as configured in the cranking advance. The primary trigger configuration is taken from an already Genboarded M20 engine, the trigger is identical so it was no mystery that it would match this engine.

To save the plugs from a badly configured VE map initially we configured the TPS high/low to read 100% all the time to avoid any fuel during cranking, and only use the priming pulse to get an initial sputter. We then knew we had the ignition order correct when the engine came to life on the priming pulse alone and never backfired. We activated the TPS again and set proper req_fuel and VE map values and now the engine cranked and ran.

We determined this through the temperature of the exhaust manifold runners after we had the engine running, but it could be heard that not all cylinders were happy. All plugs were fresh, there doesn't seem to be any spark and we can't get our strobe to work on anything but cylinder 1 ?

Clarification:

Some questions:

[config.txt] and [tables.txt]

Bear in mind that fuel has not been set properly, including afterstart and other enrichments.


History

I'm helping a local guy with installing a Genboard on a M20B25 BMW inline 6 cyl engine with Bosch L-jetronic electronics and intake and distributor ignition. The M20B25 originally doesn't come in this configuration (Motronic only) but a previous owner swapped out the block and head of the 323 for 2.5 litre parts and retained the electronics and intake (very stupid, engine ran lean on too small injectors). The stock harness will be cut-up and partly re-used and directly wired to EC connectors - a lesson learned from a previous BMW 728 project with similar electronics, meaning the stock L-jetronic connector and box will not be used.