tuning a Jetronic 320i

[dazzaboy]

I posted a message the other day about tuning a 320i, unknown to me it is a jetronic type, i had a few tips on how to tune a motronic type like fitting a 325i throttle body and inlet manifold, will this still work with a jetronic, any tips would be great,

ps. I dont fancy fitting a whole 2.5 as the insurance wont like it too much

[Ant]

Megasquirt ECU, its the only way to tweak these, there are no chips for the analogue setup you have, and with a dizzy and mech advance you'll have no joy there either dude.

try a tad more fuel pressure and a few degrees base advance more, will carry the extra right to the limiter, so be careful

HTH

[320Touring]

A bigger bore throttle body, machined head to accept a 325i intake manifold

[dazzaboy]

I thought the 325i intake wouldnt work, only with a motronic setup, please correct me if i am wrong

[320Touring]

I thought the 325i intake wouldnt work, only with a motronic setup, please correct me if i am wrong

as far as I was aware, it should work with either...

I await telling off though

[kirils]

i have a 1983 320i with l-jetronic now is running in really slow, i could hardly manage to drive 180km/h ... that is after i was messing with the timing belt and dizzy cap. first i set it up and it was really fast, it was like driving another car, but it wouldn't idle really hard starting etc.. so it's still not set up right i will need to take it to a sepcialist. so that is sure not helping...

where can these megasquir ecu be found?aand how much do they cost? my location is a bit odd Macedonia, and i'm 100% sure that i can find it here..

[ed325i]

[quote]A bigger bore throttle body, machined head to accept a 325i intake manifold


Would this work on a 323?

[Speedtouch]

A cheap & cheerful way to increase the rev limit on these (thus giving a bit more at the top end and not such a brutal cutoff in the power) is to remove the spring-loaded 'switch' on the rotor arm in the distributor. I did this with my first '84 320i and it blew away a Merc 500SL in a traffic lights grand prix

Recommend you have a cambelt in good condition before you try the mod though

[ed325i]

Thanks argos I have got a 2.5 inlet and TB in the shed. What pressure can the fuel be raised to ?

[Ant]

dont use motronic injectors with Jetronic or vs versa btw, the end result will be a fried ECU

[dazzaboy]

Is there any thing else that can be done???

Also what sort of money am i looking at for a inlet manifold and or throttle body (pref big bore)

[ed325i]

I would think a 325 inlet can be got for Ԛ£15/Ԛ£20.
I have got one in the shed waiting to go on.

[ed325i]

All the pipes are the other side on the jetronic engine so fitting the 325 inlet would not be that easy.

[Speedtouch]

Anyone ever done this conversion then? Also, which way do you rotate the dizzy to get the timing more advanced?

Cheers!

[ed325i]

If I was you I would fit motronic. easy to do on a 320.

[Speedtouch]

Is it really worth the effort for another 4bhp?

[Speedtouch]

I tried turning my car's dizzy a few degrees anti-clockwise today; it seems to have made it a little more responsive, though the car's idling a little high at around 1,500rpm (also tried adjusting the throttle stop, to no avail).

Am I correct in thinking I should turn the dizzy anti-clockwise until it just begins to 'pink' going up a hill in 4th gear, then turn it back the other way slightly to get the optimum setting?

Cheers!

[Ant]

Am I correct in thinking I should turn the dizzy anti-clockwise until it just begins to 'pink' going up a hill in 4th gear, then turn it back the other way slightly to get the optimum setting

old scholl method, works though, used to be a fave trick on the mk1 gti, 4 degrees base timing certainly pepped mine up