have changed over a 16 valve car AND REPLACED ENGINE a non turbo motor 8 valve what ecu should be used with this engine? its already is running but want to make sure I have the right ecu

I've heard of people making that swap without changing the ECU. If it runs good, gets decent mileage, doesn't knock, and passes emissions, leave it alone. I would think the O2 sensor would make minor mixture adjustments as required.

You'll have a little larger diameter exhaust than most 8 valves, but that shouldn't hurt anything.

A write-up of the conversion procedure would be a nice piece for the 700/900 FAQ's (hint-hint)

Dear Jacksonville,

May this find You well. Does this engine have a Bosch or a Rex-Regina fuel/ignition management system? The ECUs do not interchange.

A Bosch engine will have deep yellow fuel injector caps. A Rex-Regina engine will have pale blue fuel injector caps. The Bosch coil - a black plastic or aluminum cylinder - is mounted on the passenger side of the engine bay, near the firewall. A Rex-Regina coil is square, has fins, and is mounted on the front side of the driver-side strut tower (US and Canadian model).

Please post back and I'll be glad to help.

Yours faithfully,

Spook

yeah its a bosch but I need to know what number ecu I should be running with the 8 valve motor, car started up after replacing the 16 valve motor with the 8 valve one, but not sure if I need to swap out the ecu?

As Chris said, the 16 v ECU will work fine with LH 2.4. Both Dan Page and I tried the swap (928 or 571 out of a 16v an normal 8 v) and gave up trying to find any problems with it at all. There may be some problem somewhere, but our cars ran pretty darn normally with either ECU. Having said all that, the 561, 951, 933, 946 ECUs will all work for you with LH 2.4. I have a very trustworthy pal who even ran the LH 2.4 Turbo ECUs in his NA car and swears they were fine. So you have a lot of latitude.

Dear Jacksonville,

May this find you well. The following ECUs were used in 1992 non-turbo models, with B230F engines (Bosch fuel/ignition management):

Volvo Part# 3501687-2 Bosch # 0 280 000 556
3547773-6 0 280 000 933

Source: Volvo Pocket Data Booklet - Cars (700,800,900); 199-1996, p. 28 (700-900).

Hope this helps.

Yours faithfully,

Spook

The 556 ECU is California car - EGR specific. But, it works with any 2.4 system that takes the 561/951.