look what i've found (ECU chip) should i buy its ending soon

[lion_yo]

would it make a major difference here it is http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... :MESELX:IT

[jon_st205]

Major difference - no, but a few horsepower/torques, yes, at the expense of needing to run SUL.

Jon

[SuperRedMR2]

I sold mine to a guy from birmingham on ebay with exactly the same text that this guy has got! I never fitted mine so i dont know if there was any difference.

[JMR_AW11]

I sold mine to a guy from birmingham on ebay with exactly the same text that this guy has got! I never fitted mine so i dont know if there was any difference.

That explains the deja vu when I read the advert

Also, there's a lot of difference in the stock mapping between a mk1a and the last of the mk1b ECUs so I'd be wary of fitting it unless the car was carefully checked for detonation etc.

[Ben]

Also, there's a lot of difference in the stock mapping between a mk1a and the last of the mk1b ECUs

Did later 1b's have different ECU settings to earlier b's? I only ask as mine's a late '89 model, with the slightly different white paint that the last of the run had...

[SuperRedMR2]

If you have a 1989 or a 1990 mk1b you will have a different paint code as i do. We're special lol we have superwhite 2 043 - all other mk1s with white paint is superwhite 2 040 - big difference!

the ecu is different i believe, as the mk1a is more aggressive and the tvis kicks in earlier and the mk1b is more economically tuned and the tvis kicks in later

[JMR_AW11]

Also, there's a lot of difference in the stock mapping between a mk1a and the last of the mk1b ECUs

Did later 1b's have different ECU settings to earlier b's? I only ask as mine's a late '89 model, with the slightly different white paint that the last of the run had...

Yes they did.

The 3 ECUs I know of are

89661-17030 mk1a
89661-17070 mk1b
89661-17140 mk1b (late)

The 17140 ran a lot less ignition advance at high rpm/load compared to the earlier ECUs and also had different fuel mapping.

[Ben]

Lol, yes I know about the paint code. It's a pita to be honest! I have a new bootlid and engine cover to go on mine, but the colours don't quite match up

I knew there was a difference between the 1a and the 1b ECUs, but JMR's post seems to suggest that the last of the MK1b run had more changes than the initial 'a' to 'b' change... IYSWIM...

[Ben]

The 17140 ran a lot less ignition advance at high rpm/load compared to the earlier ECUs and also had different fuel mapping.

Well, you learn something new every day

So (considering I'm about as technical as a lemon) how does that translate into everyday driving characteristics?

[SuperRedMR2]

why is the different paint code a pain? unless you didnt know there was a difference before you bought the bits lol

my mate has a mk1a, which has had a respray to the 043 paint code, unfortunately he had his wings sprayed to what it should have been 040 lol looks funny.

[Ben]

Lol, it's not that bad really, just means that replacement panels are harder to come by. I new about the difference, but the panels I have were given to me following a garage-clearout. It just means that I'll have to respray them if I'm pernickety (which I'm not, so I'll probably just wack them on anyway! )

[SuperRedMR2]

lol I know what you mean about the availability...I need a rear spoiler really if I wanted to get any kind of award at JAE lol but finding a spoiler with the 043 paint code is nyon impossible, plus the people on eBay keep telling me there isnt a difference, which p1$$e$ me off really.

[JMR_AW11]

The 17140 ran a lot less ignition advance at high rpm/load compared to the earlier ECUs and also had different fuel mapping.

Well, you learn something new every day

So (considering I'm about as technical as a lemon) how does that translate into everyday driving characteristics?

Dunno for sure becaue I'm not an expert on the 4AGE but I have tried upping the timing a few degrees (at high rpm and load on the map) on the 17140 ECU on a rolling road and it only gave about 2bhp more power and the engine wasn't as smooth.

From memory the difference is 4 or 5 degrees at high rpm between the two ECUs. (in other words, quite a big difference in timing)

I think the difference in refinement was more noticeable than the difference in power but maybe I should have tried it on better fuel.

[Tiny]

give me my 17030 and 100 ron fuel all day.

[Tiamat]

the ecu is different i believe, as the mk1a is more aggressive and the tvis kicks in earlier and the mk1b is more economically tuned and the tvis kicks in later

The only reason the MK1a ECU is more aggressive is the MK1a engine had smaller injectors than the MK1b engine

[JMR_AW11]

the ecu is different i believe, as the mk1a is more aggressive and the tvis kicks in earlier and the mk1b is more economically tuned and the tvis kicks in later

The only reason the MK1a ECU is more aggressive is the MK1a engine had smaller injectors than the MK1b engine

There's lots of differences in the ECU coding and mapping between the early ECU and the later mk1b. eg the fuel enrichment is much more pronounced on the mk1a if you stab the throttle.

The 17070 mk1b is only mapped to 5200rpm on the ignition. The mk1a is mapped in 400rpm steps right up to 7200rpm.

The mk1a has about 5 degrees more ignition advance at high rpm and load compared to the 17140 mk1b ECU.

However, all the ECUs have hidden maps in them that are locked out. eg the 17140 mk1b has an ignition map with more advance at high rpm but it's locked out with a jumper wire inside the ECU.