Type3 74Fxx ecu running s14a (originally 82Fxx ecu)

[gsportcars]

Hi folks,

I hate barging into the forum with a query straight away as I have just joined but I figure the info is better here than hiding in my email inbox

Anyway I have just taken delivery of a type 3 board for a customer who has an s14a silvia. Before ordering I checked the ECU part number in the car which was 74Fxx (type3). The customer had previously mentioned getting a spare ECU when buying the car. Only now have I actually seen the ECU which has the part number 82Fxx (type 4).

This explains my confusion when Matt corrected me when ordering the board as I had asked for a type 4 board originally but based on the ECU part number I supplied, I was rightly told that it was an older (type 3) ECU.

so....

My concern at the minute is that even though the car has been running on the type 3 ECU up until now, are there any potential problems I may encounter when running the Nistune equipped ECU on the later model engine. Off the top of my head......

VVT.... Am I right in saying the type3 ECU doesn't support vvt control? If so, can I add this control to the ECU possibly using an auxillary function or output etc?

Knock control.... Possibly different knock sensors between the two models?

o2 sensors.... I know that with many other manufacturers, OBD0/1/2 models tend to use different type of o2 sensors and so on. (single wire to four wire). Is this the case between the type3/4 ecus and should I expect problems with mixture trims?

Any other potential issues I haven't thought of???

I am confident enough that we can still run with the type 3 board and 74Fxx ECU but I am hesitant to fit the board just yet.

As always, any help is much appreciated.

Gav.

EDIT.....

The customer has also told me that the 74Fxx ECU is 'supposed' to be a Mines ECU. I can't see any markings to confirm this and so I have my doubts that it actually is. But in the worst case, could this also cause and issue when using the using the Nistune board? I expect it shouldn't make a difference??

[unex]

do you know that ECU plug is different? Are you going to change engine loom? here in Europe engine loom does not cost much, and almost everything is identical except ECU plug, NATS and some other small differences, but do you really want to do this? I would say it much cheaper and much faster to change nistune board.
BTW: if your customer have second handed ECU, dont trust sticker on the ECU, because ECU cover maybe was changed ! (I had that situation once)

[gsportcars]

I have no intention of changing the loom etc. The car is currently running the 74Fxx ecu with no apparent problems.
I am happy to fit the type 3 board to this ecu and tune with that so long as I don't uncover any possible issues. I will be connecting the consult for faults and logging before I fit the board just to be sure.

I hadn't thought about the possibility of someone changing the cover on the spare ecu. This spare ecu has never been used since the current owner bought the car. I will open both ecus later today for comparison.

[unex]

the car cant be running 74F if it was with 82F ECU before, because, as I said, ECU plug is different (its impossible physically to plug in), so I would say, that one of ECU cover is changed.

[gsportcars]

Ok so on further investigation I have found out that someone previous has cut the original ecu connector off and wired in the connector for the 74F ecu.
I now have a car with a 74F ecu (apparently Mines) and a spare 82F ecu that can't be used as there is no connector.
I will speak to the owner and see if he is happy with me using the 74F ecu even though it is potentially a Mines ecu.

I expect that Mines have a means of reflashing the factory ecus so I doubt that there would be any problem when running the type3 board in this unit.
Can anyone confirm???

Otherwise I will have to swap the board and find an 82F ecu connector to wire back into the car

Thanks for the help so far too!!

[Matt]

This one is very strange!

Okay so they have a later model S14A but cut the plug and wired in an S14 plug and loom.

As for your concerns the VCT, O2 sensor etc will be the same between models. As far as I can tell the Series 1 did use a longer ECU plug compared to all other SR20DET models (for reasons I dont know!) but it should function the same otherwise

MINES ECUs will have a mines badge on the cover. I've not seen an SR20 MINES computer to know the internal changes. They either use another board or sometimes replace the ROM (middle square chip)

Go ahead with the Type 3 board in this ECU. There should be no problem using the board in this ECU

[gsportcars]

That's great Matt, thanks.
Yeah I suspect someone has changed the plugs in order to fit a series 1 mines ecu originally and maybe at a later stage someone else has noticed the ecu and swapped the mines for their standard ecu. I can't see any other reason why the loom would be cut.

Anyway, thanks again, I will get cracking with this.

edit......

Also just to confirm, the 74F ecu has no Mines sticker/badge and the board hasn't been modified at all so I am confident enough that it is not a Mines ecu.

[skylinegtrhr]

Ok so on further investigation I have found out that someone previous has cut the original ecu connector off and wired in the connector for the 74F ecu.

If connector was solder and not crimped then there is always great possibility that with time strange problems will arise so do that first before problems.

And we run on one customer S13 swap S14a loom and ECU on "old" S14 engine and sensors (only difference is ECT plug and AFM plug) without any issue

[gsportcars]

Seems someone has been in a hurry to fit electrical items to this car lol.
I am having no joy connecting consult even before the board was fitted to the ecu. And one of the main relays seems to flicker on and off quite badly a few seconds after start up which makes the engine stutter and occasionally dies all together. I suspect the very poor wiring for the turbo timer to be at fault.

I'll have to do some work before tuning this one!!

I have a cheap ebay serial consult that I will try which should determine if the connection problem is with the car or with the usb drivers (I did direct windows to the correct drivers in the nistune folder). But I will have to find a consult and ecu pinout to confirm the wiring is still connected for the consult plug.

[gsportcars]

All sorted.
Turns out the rx and tx wires between ecu and consult port weren't making a connection at all so I ran new wires and it connected straight away.
Also had fun setting the blitz I color sbc as a wire had broken on that too causing the display to loose connection with the boost controller all together.

Fun times lol.

Anyway, thanks for the help folks!