What ECU would fit instead of a red label one?

[Williewammes]

Guys,

Thinking about sending my ECU to Richard Pruen, but I need a spare ECU.
It should replace my red label ECU.

Allready tried the purple one from my other 480 (1987 testmodel from volvo), but that one doesn't work at all. Does anyone know whic ECU will work other than the red one (wich is pretty rare and not easy to find, I guess)?
I don't mind not al the electronics working, but just want to keep the car running as long as the original ECU is in England for modifaction.

So, any advice on this would be nice...

[volviz]

look here

http://volvo480.northernscum.org.uk/for ... +ecu#84478

[JohnTurbo]

Since I wrote that, i should clarify...I'm 90% sure that a blue would work, but since nobody i know of has tried it, i can't be any more certain than that.

Blues and reds are both hard to get hold of mind!

[rpruen]

Yes a blue ECU will work, if the purple/orange one doesn't.

The cars fitted with red (maroon) ecus can have two possible flywheels, either the smaller early type clutch, or the later bigger one. The blue ECU goes with the later type clutch, and the orange or purple ECU with the early type.

Idealy you need to swap the Fuel ECU and MAF as well as the boost ECU as a set. Unless it's a temparary solution to keep the car running.

Regards

Richard

[overboost]

The cars fitted with red (maroon) ecus can have two possible flywheels, either the smaller early type clutch, or the later bigger one. The blue ECU goes with the later type clutch, and the orange or purple ECU with the early type.

Regards

Richard

All ignition ecu's will work in all 480's. Early ones require two 12V feeds, where as later ones only one.

It is simply a case of adding a wire to allow the later cars to run the earlier ecu's.

[robkendall]

All ignition ecu's will work in all 480's. Early ones require two 12V feeds, where as later ones only one.

so a turbo ecu would work in an NA car? (and vice versa)
thought the fuel ratios and things would be totally different?
rgrds
rob

[robin_xr4i]

so a turbo ecu would work in an NA car? (and vice versa)
thought the fuel ratios and things would be totally different?
rgrds
rob

I dont think n/a 480 use bosch managment, so i think he means all turbo cars?

[overboost]

Thanks Robin.

Yes thats what i meant.

Turbo 480's

[rpruen]

All ignition ecu's will work in all 480's. Early ones require two 12V feeds, where as later ones only one.

It is simply a case of adding a wire to allow the later cars to run the earlier ecu's.

That isn't true.

Blue ECUs will not work on the early cars. At all, unless you change the flywheel.

Purple ECUs will not work on 92+ cars at all, unless you fit the early type flywheel.

Some orange ECUs will work with later engines (these are limited to spares manufactured after 92, but for pre 92 cars). They are in fact more like a red ECU.

Some other orange ECUs can be made to work with a later flywheel, by adding an eprom board (if not already present), and changing the eprom.

As someone asked.....

Yes you can fit a complete LH/EZK setup to an ES engine. There isn't anything to be gained unless you are going to supercharge it. Purple and orange ECUs would be a direct fit I think (but I have not tried). Best option would be a late type clutch/flywheel, and red ECU though.

Richard

[overboost]

have you ever compared 2 flywheels Rich. early and late...????

the difference being...???? apart from of course the obvious clutch size.

[rpruen]

The different number of teeth, and change in the TDC marking. I have a picture, but can't upload it to my webspace because I'm not connected to my ISP, but by a mobile phone.

I'll email you the pic if you like.

Automatics all have the same plate with holes in it, and you can plug in any ECU you like and the engine will run (poorly quite often, if they aren't a matching pair of ECUs).

Richard

[TommiS]

Purple and orange ECUs would be a direct fit I think (but I have not tried).

Yes they are, I have tried and works 100%. Purple was -89 and orange was -91.

[volviz]

Richard is back..

[overboost]

The different number of teeth, and change in the TDC marking.

All the flywheels are a standard bosch 60-2 pattern. I've compared two flywheels and found that the missing teeth vary by around 5 degrees between the early and late types. Certainly not enough to stop them from running.

the engine will run (poorly quite often, if they aren't a matching pair of ECUs).

Richard

I have a 95 car with blue ecu's on. I tried an orange single layer ecu out of an '89 car. It wouldn't start.

I opened up the orange ecu and added a link wire between pins 5 and 6, and voila. It runs fine. The link wire is already present in the blue ecu.

I would assume from this that a blue ecu would go straight on an orange ecu'd car and work. I don't have one to try though.

[rpruen]

All the flywheels are a standard bosch 60-2 pattern. I've compared two flywheels and found that the missing teeth vary by around 5 degrees between the early and late types. Certainly not enough to stop them from running.

In that case I may have miscounted the teeth. 5 degrees of timing is quite a lot, though it will run, it's not a great idea.

I have a 95 car with blue ecu's on. I tried an orange single layer ecu out of an '89 car. It wouldn't start.

I opened up the orange ecu and added a link wire between pins 5 and 6, and voila. It runs fine. The link wire is already present in the blue ecu.

I would assume from this that a blue ecu would go straight on an orange ecu'd car and work. I don't have one to try though.

It will make the engine pop and splutter, maybe you can get it to start, but it's not very helpfull.

The ECUs also swap signals, and mismatched pairs don't get on well together. Sure you can make an orange dual layer (or one converted to dual layer) run resonably well on a blue ECU car, but it's easier and cheaper to use a red ECU (about 80% of them seem to be dual layer), and will work with the blue or orange fuel ECUs.

Richard

[overboost]

All the flywheels are a standard bosch 60-2 pattern. I've compared two flywheels and found that the missing teeth vary by around 5 degrees between the early and late types. Certainly not enough to stop them from running.

In that case I may have miscounted the teeth. 5 degrees of timing is quite a lot, though it will run, it's not a great idea.

I have a 95 car with blue ecu's on. I tried an orange single layer ecu out of an '89 car. It wouldn't start.

I opened up the orange ecu and added a link wire between pins 5 and 6, and voila. It runs fine. The link wire is already present in the blue ecu.

I would assume from this that a blue ecu would go straight on an orange ecu'd car and work. I don't have one to try though.

It will make the engine pop and splutter, maybe you can get it to start, but it's not very helpfull.

The ECUs also swap signals, and mismatched pairs don't get on well together. Sure you can make an orange dual layer (or one converted to dual layer) run resonably well on a blue ECU car, but it's easier and cheaper to use a red ECU (about 80% of them seem to be dual layer), and will work with the blue or orange fuel ECUs.

Richard

This car is not popping and spluttering. It starts on the button and this weekend has done a 150 mile round trip with no hesitation or rough running.

As for the ecu's swapping signals, I have cut the pulse train wire, obviously leaving the rpm signal wire still in and the car runs exactly the same. Wideband afr gauge on and there is no change.

Everyone seems to think the LH jetronic is a complex and ground breaking system......... it was in 1984 when it appeared on saab's. It's features are very limited.

[rpruen]

This car is not popping and spluttering. It starts on the button and this weekend has done a 150 mile round trip with no hesitation or rough running.

As for the ecu's swapping signals, I have cut the pulse train wire, obviously leaving the rpm signal wire still in and the car runs exactly the same. Wideband afr gauge on and there is no change.

Everyone seems to think the LH jetronic is a complex and ground breaking system......... it was in 1984 when it appeared on saab's. It's features are very limited.

No your car won't pop or splutter. You have retarded the timing by fitting the early ECU, and then further retarded it by cutting the load signal wire. Quite what you hope to achieve by that is beyond me, unless you have some sort of 'unichip' type piggyback device to re-map the ignition timing, or are running very high boost.

Fitting a late ECU to an early car has the oposite effect, and will cause it to be hard to start, since the timing at cranking is too advanced. This is why I gave up adjusting the static ignition timing. The engine either stops dead while cranking, or tries to go backwards.

The LH injection itself is a little better than the Saab version, in that it does have long and short term fuel trim. It also makes more use of the oxygen sensor than you may expect.

However the EZK is actualy quite smart. It does things like per cylinder knock control, ignition timing vs boost tradeoff, and is torque based (a bit like the motronic that came after). It's also got a few more tricks, like altitude correction (boost increase with altitude) and torque limiting to help stop exccesive wheelspin.

As for not seing any change in AFR, that's to be expected since you have isolated the LH ECU and it will just go on doing what it is programmed to do. The EZK may signal for more fuel if it detects knock, but I am not sure since it's going to be in some sort of failsafe mode. What you should be looking at is ignition advance, not AFR, with the load signal connected, and also disconnected, then you will see some changes.

Richard

[overboost]

The load wire is connected, and was only removed for test purposes. I feel the timing is advanced with orange ecu on as car is perkier on part throttle. As for popping and spluttering, i quoted yourself and now u retract it...????

I can't comment on the late ecu onto early car part as have not tried this. although my findings would suggest retarded from standard ignition in that configuration. Only higher up in this post, you claimed the 2 flywheels had diff amount of teeth, never mind offset tdc pickups.

As for fuel trim and adaptive ability, to my knowledge, Motronic systems were the first ecus in 'common' cars to support these features. sure enough the LH system adjusts at idle for emissions purposes, but it doesn't learn. This is supported by the fact that the airflow meter has an adjusting pot. When it is set correct the afr should be at 14.7, therefore little adjustment required

When does the EZK do these 'things'. .??? when its dreaming of being a much more modern system.

[rpruen]

The load wire is connected, and was only removed for test purposes. I feel the timing is advanced with orange ecu on as car is perkier on part throttle. As for popping and spluttering, i quoted yourself and now u retract it...????

Nope a newer ecu on an older car will tend to have too much advance for the cam, and also hard starting due to the same. That's why above I quoted the part where you where talking about a newer ecu on an older car. Sorry if that wasn't clear enough.

It's made more complicated due to the different scales of the load signal, so short of doing extensive testing (that I have no intention of doing) then there is no way to know what will happen in all conditions.

I can't comment on the late ecu onto early car part as have not tried this. although my findings would suggest retarded from standard ignition in that configuration. Only higher up in this post, you claimed the 2 flywheels had diff amount of teeth, never mind offset tdc pickups.

So I miscounted teeth, it's easy to do if there are so many of them, all the same size. So that's cleared up?

As for the ignition timing, it needs some testing to be sure, because of the mismatch between the load singal, and what the ecu expects to see. I would expect the ignition timing to be advanced too much in some places, and retarded in others.

As for fuel trim and adaptive ability, to my knowledge, Motronic systems were the first ecus in 'common' cars to support these features. sure enough the LH system adjusts at idle for emissions purposes, but it doesn't learn. This is supported by the fact that the airflow meter has an adjusting pot. When it is set correct the afr should be at 14.7, therefore little adjustment required

The LH does have long and short term trim. It's not just active at idle either. That's why these cars can go a bit strange if the oxygen sensor goes haywire. The CO pot is there to make up for tolerances, in both the electronics, and the engine. Modern cars have the same adjustments, but since they have the advantage of flash memory, the adjustments are stored in NVRam. The LH doesn't have any storage that survives for long without the battery connected, so has a potentiometer.

The LH doesn't have to be that smart, it;s looking at the input from the air mass meter, so it can put in the right ammount of fuel easily. It doesn't need to do anything fancy to do that. It has some tables of fuel trim, and a map of sorts to allow for quirks of the intake to the MAF (the bend right before the inlet mostly).

Disabling the fuel trim is easy, just unplug the oxygen sensor. It then just adds the quantity of fuel required for the measured airflow ,it adds a little extra too, how much depends on the year.

When does the EZK do these 'things'. .??? when its dreaming of being a much more modern system.

Volvo say it is able to retard the ignition on a per cylider basis, as well as reduce the boost if required. Are you going to argue with them as well?

Proving the ECU is aware of torque is easy too. Put a standard car on a dyno, and do some part throttle runs (somewhere between 60 and 100% throttle). You will be able to see that the pressure over the throttle butterfly is near zero most of the time, but that you get some fairly flat torque curves. Now try it with another car (say with K-jet, like and RS turbo) you get a completly different torque curve, one that starts out going quite high, and drops off as the pressure changes over the throttle valve.

This has been interesting.

Richard

[Williewammes]

Wow,

Didn't expect this topic to get so technical complicated

I'll just go for a blue or red one, no matter what is possible.
Wouldn't want my engine to experience strange and harmfull things while having the normal ECU in the UK.

Still searching though , Anyone who can help me find a spare blue or Red ECU? Would be great!!