ECU help

[sunnysr]

I have a tech 1 325 sport i bought it with no ecu ,it has 2 rows of pins for a ecu so i bought a 2 row ecu from ebay for a 325 , now i have connected it and the car will turn over and i am getting a good spark but the fuel pump was not running ,so i have put a live feed to the fuel pump so now i have fuel to the situation but still no start so my question really is ,is could i get the wrong type of ecu between Motronic or these L-Jetronic ones ? the car had an immobilizer fitted i think this may have something to do with the pump not working but any other clues as what to try next would be a help also would the wrong ecu stop the injectors working if wrong ecu is even a possibility

thanks for any help

[Grrrmachine]

PLEASE use some full stops. It's really hard for me to read otherwise.

Wrong ECU can very much be an issue. While Jetronic and Motronic have different numbers of pins, there is more than one version of Motronic with 55 pins. You need to compare the number on your ECU to this table to make sure it fits a 1987 model:

http://www.e30zone.net/e30zonewiki/inde ... st_of_ECUs

If you've got the right kind of ECU, you need to work through the rest of the trouble points:

http://www.e30zone.net/e30zonewiki/inde ... oubleshoot

READ THE WHOLE ARTICLE. There is a wealth of knowledge in the testing procedures, and the more feedback you provide, the more able we are to help you.

[Speedtouch]

What age is the car, and which ECU did you buy? It should have a part number on, e.g., 0 261 200 073.

Wrong ECU could well prevent the injectors working, as they varied in impedance between early and later models.

[sunnysr]

Sorry about the full stops its easy to get lazy on the internet .
The car is 87 ,the numbers on the ecu seem to be wrote on and are hard to read 0461 200 073 ,it looks like but that does not seem to relate to anything.Serial number is p519001 .I got it from bmw spares shop on ebay.I will have a further look through the wiki your right there is plenty of info there i will go have a good read of that Thank you.

[Grrrmachine]

073 is the number you need, so it looks like you have the correct ECU (although Speedtouch should confirm this ). And in that case, you need to do more checks; you don't know what bodges the previous owner did, or even if the engine is sound.

Start with a compression test...

[sunnysr]

Thanks just mainly wanted to rule out the ecu being at fault out,who knows what problems could be in that engine i bought the car without hearing it run ,knowing it had stood for at least 10 years(it was cheap enough to take this risk) .The guy who put it in the container bought it from someone who had it stood in their garden and had the philosophy of "well it drove in there so it must run haha "
Thanks for the reply s i am happy now that the ecu is good i will investigate further .

[Speedtouch]

Yes, a Tech 1 Sport/early chromey 325i will usually have an 0 261 200 073 ECU.

However, these early ECUs are reknowned for being a bit unreliable owing to a twin PCB design, so it may be worth trying a known good one.

Another notorious weak point with these is that they had a flywheel position sensor in addition to the crank position sensor (CPS), and the trigger dowel falls out of the flywheel, and ends up in the bottom of the gearbox bellhousing, however, if your car is sparking OK, then this is unlikely to be the case.

Also check the green wire that runs behind the glovebox, as this often falls out of the connector and causes non-start issues - do a search for 'green wire' on here to find out more on this.