MBE ECU issues - now sorted

[BBL]

My car was supplied w/ MBE 992 ECU, and it worked well enough, but mapping was tedious, as there was no "live" mapping - and no person that I am aware of that I would call an expert in these matters within a radius of thousands of miles, at least not with a MBE device. 😬 I have faith in the mapper I use 400 miles from here, but he is not specifically familiar w/ MBE units/software.

 

So I got a current 9A4 with a suitable start map, swapped pins around as required on engine loom, and with that it will start, but barely runs, and sounds like it is being tortured at idle. Any application of throttle causes it to die, frequently with a pop or belch from the exhaust. Clearly it cannot be driven. I was very careful swapping the few pins that needed rearranging, and am assured the map is fine. So...

 

Engine is Cosworth 2.3 Duratec.

Loaded latest version of Easimap 6.

Loaded latest .ec2 file on Easimap and on 9AA4.

Any suggestions, please?

 

Edited by - BBL on 17 Sep 2013 14:38:38

[Alaskossie]

Sean,

 

Very sorry to hear of your difficulties. You and I have nearly-identical engines. As you may recall, my Cosworth-supplied ECU allowed the car to run fairly well with the original, default settings (sharp bucking at off-throttle at low speeds, severe flatness above 9000 ft. altitude -- no problem where I live now).

 

But Nathan Down in Boulder was unable to get the link to work so that he could read and adjust the mapping on his laptop. Since I am several thousand miles from Nathan or any other person with Seven mapping experience , I am just crossing my fingers and soldiering on. If the engine ever goes duff, I'll probably just have to try to sell the car.

[Croc]

Sean - you may want to put a post like this on the CSR forum. Some of the European guys on there have gone a some ways down the road you are trying to travel with their CSRs using the same engine. I think you also know that Karl near me ended up tuning a new unlocked MBE ECU with his local mechanics using SBD as phone consultants - hellishly expensive but may be an option. A last suggestion - what does Cosworth USA say? They sell these engines and ECU but offer zero support? Cheers Mike

 

[The Pikey]

can you plug it in to a laptop using easymap?

[Paul Deslandes]

Where did you source your ECU and starter map? Did they give you a setup procedure to adjust the Throttle Position Sensor (TPS).

 

It could be the TPS setting being wrong for your new map and this is advancing the ignition too much and which can make the engine sound like a bag of spanners at idle.

 

If you can run Easimap connected to the 9A4, check the TPS voltage which, for a 'standard map' 9A4, is about 360mV. You can make the same measurement with a digital multimeter at the TPS wiper (central pin). I seem to think that the Cosworth/Caterham setup the idle setting is closer to 450mV which would push the ECU into map sites 1 or 2.

 

If you're a bit more adventurous, again in Easimap, look at the Throttle Index map and see what the voltage is on the table at site zero. Adjust the TPS so the voltage is about 10 - 20mV less.

[Simon.Rogers1]

I supplied the ECU and starter map for Sean.

I was on the phone to him late last night trying to compare maps and settings etc.

 

He has a new start map for the engine but is very rough.

 

We are using the compare maps function in easi map and this shows some really quite significant differences in the advance settings and crank position sensor. But they are so opposite I can not believe it would even run!

 

We have the old 992 map and new start map available and can see everything.

 

I suspect its something like the TPS and have suggested to Sean he looks at these first. The main difficulty is the time difference!

[Paul Deslandes]

that's good, at least he's getting proper support

 

[BBL]

With Simon's help, I have tried a few things, but not yet there. The compare maps function shows differences that are way off from each other, but the 992 map obviously works, and I am sure the map supplied w/ the 9A4 works, so I suspect either there is an errant setting specific to my engine somewhere, or I have somehow buggered something.

 

I think the time difference is the secondary difficulty, and my lack of knowledge/familiarity is the primary. I know enough to be dangerous, but not enough to be adequately effective on my own.

Example: Where the devil is the value for TPS voltage in mV?

 

Tom - The OBD2 port on my car was not wired to the ECU, and yours is probably also not wired. To connect to the MBE ECU, you only need to connect pins 8 (CAN-Low) and 9 (CAN-High) on the ECU to pins 14 (CAN-Low) and 6 (CAN-High) on the OBD2 connector. Or, what I did: get another OBD2 connector from just about any junked car built in this millennium, and splice that in. SBD sell a OBD2 with pre-wired leads and pins that you can temporarily load into the ECU connector for mapping, and then remove when done - a very elegant solution.

 

Mike - Cosworth, both USA and UK, have been great with support for me all around over the past 7 years, but I am now replacing their ECU with a newer one from elsewhere, so I have not contacted them for support on this issue. I may try SBD, but I thought (naively?) that replacing a MBE992 ECU from 2006 with a MBE9A4 ECU from 2013, with the same form factor and connector, would be a relatively simple operation. Good point about trying the CSR forum. That had occurred to me, but I thought most of them would be on here anyway.

 

Huge thanks to all for suggestions. I've been monkeying around for days with limited progress.

 

 

EDIT -- clarification for Tom

 

Edited by - BBL on 13 Sep 2013 17:47:59

[Paul Deslandes]

when you say 'where's the TPS voltage, do you mean how do you view it in Easimap?

[BBL]

Yes.

 

EDIT -- Sorry! Yes, please.

 

Edited by - BBL on 13 Sep 2013 17:52:06

[Paul Deslandes]

ok, are you sitting comfortably?

 

Assuming you have Easimap open and your PC is talking to the ECU:

*find the speedo looking icon on the tool bar at the top of the screen, and click

* on the drop-down, click on the + sign next to Throttle Position and again on the next level against 'Throttle Position Limits and Default setup'

* click on 'Throttle Angle 1'

*click on 'open'

 

You should now have a box on the screen headed Throttle Angle (Raw). This is displaying the value in volts, e.g. 0.360 (which equals 360mV

 

Any good?

 

[BBL]

4.70 - w/ ignition on, engine not running

Seems too large of a value. Must be metric volts.

I'll try changing it to .36

 

Edited by - BBL on 13 Sep 2013 18:06:30

[Paul Deslandes]

ye Gods , that suggests that the TPS is at the full throttle position. I would initially suggest you do two things:

 

1. check that the TPS is connected the right way around and that the ground connection is

ok - should be as your previous 992 setup was presumably ok

2. once that's confirmed try opening the throttle, without the engine running, and see if the voltage changes. Do it just a little bit as I'm a bit concerned that the TPS is hard against its end stop and pushing the throttle hard might damage it. If the voltage goes down as you open the throttle, the TPS is wired wrong.

What throttle bodies do you have and do they allow you to adjust the TPS mechanically, i.e. turn it with the mounting screws slackened off?

 

[BBL]

If a realistic value is 0.36, how did it ever run using the previous ECU with a setting of 4.7? How can this be??

 

EDIT -- I see; not a setting, but a measurement. Still, how can this become so far off just by changing the ECU?

 

Edited by - BBL on 13 Sep 2013 18:23:27

[Paul Deslandes]

I'm wondering if the TPS ground has come off in the connector when you made the changes. If you can unplug the TPS, check the connections to the ECU plug with a meter. I mean between the TPS connector and the ECU plug

 

Edited by - Paul Deslandes on 13 Sep 2013 18:23:47

[BBL]

It is a bit after 10:30 a.m. here, and I am watching our 7-year old today, so I cannot devote significant effort to this any longer this morning, but a huge THANK YOU Paul, as I believe the problem has been isolated to the TPS. Simon and others suggested this as a culprit, but thank you for walking me through it. I can probably get help locally now that I know where to focus. Cheers!

 

And thanks again Simon, as I learned more about Easimp from you in a few e-mails than I ever did apprehensively poking through it on my own.

 

😶‍🌫️

[Paul Deslandes]

Well, I hope its been of some help. Once you've sorted out the connections, with the throttle at idle, adjust the TPS voltage to 0.360 or a bit less and get the engine running. Once its warmed up, and idling at the correct revs, check the voltage again and also the Throttle site which should be just in '0', so that when you press the throttle, the voltage rises and the ECU moves progressively into site '1' and beyond.

 

Good luck with it Sean, don't hesitate to blatmail me if I can help in any way, and please let us know how you get on.

 

Paul

[BBL]

Ignition on, engine not running, TPS voltage is 4.7, but as I depress the accelerator pedal, the voltage goes DOWN, not up. If the TPS is wired incorrectly, how did it work like this using the previous ECU?

 

Is it feasible to simply reverse the TPS map, with 4.7 in cell 0 and 0.whatever in cell 15?

[Paul Deslandes]

Sounds like the TPS is wired back to front. Could be that the wires to pins 4 and 23 on the ECU connector from the TPS are reversed. I would be inclined to correct the wiring fault rather than fudge the TPS index map as I don't think it will be stable or reliable, although I can see the attraction of trying it 😬. It should be easy enough to sort out the TPS connector wiring and once its done, its done.

 

ECU pin 4 is +5V reference, pin 20 is the TPS wiper (TPS variable voltage output signal) and TPS ground can go to either pin 5, 23 or 24 as they're all 0V (ground). Mine goes to 23.

 

You're nearly there.

 

Edited by - Paul Deslandes on 13 Sep 2013 22:57:47

[Simon.Rogers1]

Has to be the tps back to front!

[BBL]

Aha! I had moved pin 23 to position 31, because the Cosworth drawing for their YD8048 engine loom indicates pin 23 as "Cam Position Return", and the 9A4 diagram indicates pin 31 as "Cam Return". So, I just tried moving pin 31 back to position 23, but that produced a number of red window warnings about TPS in Easimap.

 

The YD8048 diagram lists the following, which the 9A4 diagram lists as 0VA:

Pin 5 - Sensor Return

Pin 23 - Cam Positon Return

Pin 24 - n/c

 

It also has Pins 16, 19, and 31 as n/c, which obviously indicates those pins are not used.

 

YD8048 diagram lists the following for TPS:

Pin 4 - Throttle Pos. Vref, Engine Oil Pressure Vref

Pin 20 - TPS

 

It would seem my TPS must be wired to ground on pin 5.

I'll try swapping pins 4 and 5 and see what happens. EDIT -- Well, that didn't work, so putting those back.

 

Edited by - BBL on 14 Sep 2013 00:11:58

[BBL]

I'm still mystified as to how the TPS could work for for years configured exactly as it is now with the 992 ECU, and then swap to a 9A4 ECU and suddenly the TPS is wired "wrong".

 

Anyway, maybe I can determine which pin is which on the TPS-to-engine loom connector and do some pin swapping of +5Vref to GND there.

 

 

edit -- swapped pins 1 and 3 on the 3-pin TPS connector, and all is now right with the TPS. Thankyou, once again.

 

Now I'm getting "Bad Crank Tooth Pattern" in the ECU Status box. Hmmm... as I do not currently have any undiagnosed methamphetamine or dental issues, it appears I may have a few more ECU tweaks to perform.

 

Edited by - BBL on 14 Sep 2013 06:28:29

[Simon.Rogers1]

That now makes sense if you look at the difference in the two maps. Yours was 0 deg and the new map was 263 deg.

[Paul Deslandes]

you need to be a bit careful just swapping 4 and 5 in case another sensor/wire uses 5 as its 0V/ground return. This could upset something else or even short the +5V reference to ground. Make sure only the TPS wire is swapped.

 

You can view my connection table, albeit for a Vx engine not Duratec here which might help. Click on the Schedule tab.

 

Can't help re why it worked before though, unless Cosworth wired their's back to front for some reason. Seems unlikely though.

 

edited for spelling (don't you just hate that)

 

Edited by - Paul Deslandes on 14 Sep 2013 10:18:30

[BBL]

TPS issue sorted.

Bad Crank Tooth Pattern: Tried resetting to 0°, which did not work. Set at 263°, it starts, but runs rough. Both show the BCTP warning. Any ideas?