325 idle poor running help

Post Sat Oct 19, 2013 8:18 am

hi i have just got a e30 325 baur and it has been stood for a few years, from abit of research i think it was a 320 to start with then was converted, it is running a Jetronic system with a air sliding valve, plus a have seen that it uses the in tank fuel pump(which is noisey) as well as a external pump behind the sill.

This is the first e30 bmw i have own and fancied a little project, the idea was to service the whole car and get it ready for the summer,

have many people had any joy with them, the car starts and idles really high around 2k, i have checked and replaced alot of the vacum hoses. But before i start spending money on expensive parts.

any help would be great.

cheers

Post Sat Oct 19, 2013 8:37 am

To start with, are you absolutely sure it's a 325i? I find it hard to believe that someone would take the time and trouble to make a 2.5 lump try to run on the dinosaur engine management system of Jetronic.

If it is Jetronic then the number one culprit of a high idle is the air slide valve.

Post Sat Oct 19, 2013 9:50 am

It has 6 cylinders, eg 6 spark plugs,

how can you fix the air slide valve? clean out with carb cleaner. All i know is it doesnt run a electronic icv and has a air slide valve just below the tb. It was A 320 and its a 325 now

Cheers

Post Sat Oct 19, 2013 9:58 am

The 320 was also a six-cylinder, and the 325 was never fitted with Jetronic, so making a 2.5 engine work from an ECU that thinks its only got two litres will inevitably run badly. It may however be a 323i, but your chance of it being a 325i with Jetronic is less than 1%.

There is a way of testing the air slide valve here:

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

Post Sat Oct 19, 2013 10:11 am

Is there any engine numbers that would tell you what it is? also should it still start with the afm not plugged in, how can you test the afm?

Cheers

Post Sat Oct 19, 2013 10:34 am

The engine number is stamped onto a flat surface of the block, just above the sump, underneath the starter motor. You might need some sandpaper to rub it back to read it, but it'll start with either 20, 23 or 25.

The engine may start with the AFM unplugged, but if you try and rev the engine it will be really lumpy and may stall. The full testing procedure is here:

http://www.the944.com/afm.htm

Post Sat Oct 19, 2013 10:43 am

Thanks very much what should i do with slide air valve? clean,or replace? how and where from.

Thanks for all your help.

Jon