E30 Zone

So, the old high comp 325i engine is finally in place in the 320i shell.

Out with the old... an L-Jetronic M20b20 connected to a 3 speed automatic gearbox:



And in with the new... High comp M20B25 with sport C/R gearbox. The engine has been upgraded to accept the facelift loom and ECU:







The engine is now in place and the loom on the car has been modified to accept the round C101 plg (thanks to willnz for the wiring guide, and ricey46 for doing the soldering/heatshrinking - it all looks very OEM).


Once the engine was in situ we decided to give it a test fire, and it runs - but there is some serious backfiring going on!

The strange thing about the 2.5 engine is that when we originally stripped the front end to replace the timing belt etc, we noticed that the timing on the car seemed to be off by a tooth or two. This was reset to standard when we put the new belt on.

Could this be the reason that the car is backfiring now - is there any reason why the timing on the car would have been altered previously?

Or is it simply because the car was running with just the 6 branch on?

Or something else entirely?

Was the engine running ok before your installed it?
If the answer is yes i would re check the timing first.
If the answer is no start with the basics, check the plugs / leads / cap / rotor and make sure there are no airleaks.

Steve

The engine ran OK in the car that it came out of, which is what now makes me think that the timing was deliberately set the way it was (still can't figure out a reason why though). I'll definitely be checking over the basics before mucking about with that though.

How's it going now Aly?? Started lovely when we connected the leads right on the dizzy didn't it!!lol.

looks suspisciuosly like that dodgy weegie neil helping you?

fuzzy wrote:looks suspisciuosly like that dodgy weegie neil helping you?

"Helping" is a bit strong, ask him about the heater hoses

But yeah, Neil and Paul have both been round giving me a hand with the conversion, it's been a good laugh.

The engine is now running very nicely, I actually quite like having the 3.45 diff on there for the time being, makes 1st and 2nd gear a bit longer. It will eventually come off for the 3.91 slipper though.

I've got a few more days to finish the tidying up, MOT is booked for Thursday...