Tuning MegaSquirt for 998 NA
Turbo Mini Forums

When in use in the car, are you actually powering the sensor from 12V?

If you are powering it from 5V VCC from the ECU, it may not be getting enough juice.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Done:
Yellow wire to ground - shiney LED.
Yellow wire to hall sensor green wire (ms second trigger wire removed), start engine - No shiney LED

I have a second Hall sensor, I'll give that a go.

’77 Clubman build thread
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=618189

Siamese 5 port EFI testing
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=611675

Paul, I'm powering from 12v.

’77 Clubman build thread
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=618189

Siamese 5 port EFI testing
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=611675

Looking at the thread that Paul refered to earlier: MS Trials & Testing > MS hardware configuration

Edited by Graham T on 22nd Mar, 2010.

’77 Clubman build thread
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=618189

Siamese 5 port EFI testing
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=611675

I regularly buzz it up to the rev limiter at 6000rpm. I'm certainly not aware of any problems with the cam sensor.

You need to get that LED flashing before you go any further.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

I know I wrote that at the time but with hindsight, most logic devices accept anything over 3.5V as a "1" and anything less than 1.5V as a "0".

So I don't think it's an issue.

As Paul says, you need to figure out why you Hall switch isn't switching an LED.

TBH a defective Hall switch is unlikely, unless it has been physically damaged.

Gap ???

Wiring ???

Remove it from the dizzy (I assume you have it in a dizzy housing) and try the LED test just moving it to and away from a piece of steel.

Also, is whatever you have in the dizzy presenting a clean edge, is the shaft and whatever is triggering the switch actually turning ??? My optical wheel is clamped by a single nut so if that came loose I would lose my signal, just as an example....

Schrödinger's cat - so which one am I ???

Sorted.

Flashing LED with new Hall sensor installed

The old one had "rubbing on the inside edge, So I have Verrry gently tickled the inside edge of the trigger blade on the lathe. Tried in dizzy body and rotated manually. No rubbing now.

And I have a green line.



Got AFR's at tick over matching, but still around 11.5 - 12. Pulse width at 1.345. Any lower and it starts hunting, so I will assume that is due to the injector size.

Slowly getting there now. 1 degree at a time!

’77 Clubman build thread
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=618189

Siamese 5 port EFI testing
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=611675

Good news, it tends to be the mechanical issues that let the electronics down... :)

Not so sure about the AFRs vs injector size, it should be possible to compensate for the size with the "req'd fuel" setting.

Maybe your open time setting is wrong ??? It's just a software setting that skews the actual time based on what you think/know the actual times are.

Schrödinger's cat - so which one am I ???

Good call Rod... Again!


Opening times I used:

http://www.siemensdeka.com/index.php?main_...&products_id=11

1.14ms @14Vdc



then the same part number, but under the continental banner:

http://www.racetronix.com/product/Injector...91_Brochure.pdf

1.3ms

I'll try the change to 1.3ms and see what happens.

’77 Clubman build thread
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=618189

Siamese 5 port EFI testing
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=611675

Try it the other way too, ie a shorter setting.

There is a thread on here somewhere where Jean explained it but I can't remember which way around the effect was/is.

Schrödinger's cat - so which one am I ???

The problem at such low pulse widths is that the injector characteristics are not linear.

Something about that here:

http://www.msextra.com/forums/viewtopic.ph...ng+time#p235975

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Excellent link Paul, I'd not read that one before.

Jean's statement in there sums it up

"As it has been mentioned before, the "opening time" used is a misnomer. It should be called dead time because it is the result of the fuel not being injected when the injector is opening minus the fuel being injected during the closing time."

Schrödinger's cat - so which one am I ???

With the hybrid mode, I can run pulse widths down to 1.8mSec without an issue, but I could not run the pulse per cylinder mode due to this problem.

Graham, why are you running such large injectors on an NA 998? The standard MPi ones would have been OKish.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

When I started out on this project, It was to put in my planned (eventually) 1293, either Turbo'd or supercharged. (It was originally to be Rotrex Supercharged. But I have gone off that Idea, so I am now going down the GT1752 route.) As the shell is still being built
for my turbo mini, I decided to get things going in the Clubman, hence as I had the 63lbs/hr, I decided to try to use them, rather than spending more. (and a set of 82Lbs/hr)

I looked at some MPI ones just a few weeks back, but at £96 each, I decided they could stay on the shelf. As I could not find anything around the 46Lbs/hr, High Z, I bought a set of SAAB turbo 33 Lbs/hr that I tried on the test engine, But have not gone further with as I thought they may be too small after getting them.

’77 Clubman build thread
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=618189

Siamese 5 port EFI testing
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=611675

You can get the MPi ones a lot cheaper off eBay.

I think these are the same - check

http://cgi.ebay.co.uk/ROVER-220-TURBO-420-...=item35a4dc4a84

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Actually the 33 lbs/hr should be ok for an NA 998. This should be good for around 50 to 60HP depending on BSFC and effective duty cycle.

Jean

http://www.jbperf.com/

Thanks for the link Paul. I'll look a bit closer, but the only reference I can see so far for the Rover 220 turbo is for 230cc/min. I'll look a bit harder as soon as I get a chance.

Just preparing for a trip to Holland, so all testing is on hold until I get back Easter weekend.
I'll have time to look properly whilst I'm away.
Perhaps I'll install the saab injectors again before I outlay anymore £££'s.

’77 Clubman build thread
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=618189

Siamese 5 port EFI testing
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=611675

There are a couple of different types of Rover injector, but some of them are 460cc if I remember right.

’77 Clubman build thread
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=618189

Siamese 5 port EFI testing
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=611675

Those injectors should cure the idle problem, but you will have to get a bit more accurate timing at the top end.

We have downloaded the latest TS, but haven't used it on the car yet. The latest .jar seems to cure the problem. I think it is another issue related to the USB/serial conversion.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

I too was "forced" to move to 993.1 a few days ago and, although only on the JimStim, I'm getting some pretty erratic readings especially on ignition timing...

I don't quite understand why the upgrades are mandatory ???

I still use much earlier versions of a lot of software because the earlier versions are better or more stable than so called "upgrades" but I'm usually given the choice.

It's a shame Jean's siamese code can't be accessed properly by MegaTune, with all the hassle I've had with TunerStudio, I would have preferred to stay with MegaTune.

Schrödinger's cat - so which one am I ???

Now that I have confirmed that I have the same problem after a mandatory "upgrade" I have posted the question on the MS-Extra forum.....

Why can't I keep the working version ???

Schrödinger's cat - so which one am I ???

33lbs/hr injectors installed and up and running.

After a bit of fighting with Tuner studio, I manged to get it stable enough to do some tuning, Firstly getting tick over to a fairly reasonable level. Just a bit more adjusting to do there though...

With the smaller injectors I’ve seen better results through the rev range, and making injector timing adjustments has been easier. I see more definite results to the changes made, where as with the larger injectors, changes in injector timing seemed to give more random results.
Setting wise, I have:
33 lbs/hr injectors
req_fuel at 2.60ms
Alternating injector staging. (Not sure if I should be using alternating or simultaneous?? Anyhow, this seems to be giving the best result at the moment.)
Dual injector timing using tables.
I have timing trigger set to start of pulse, with timing table 2 set at 0deg across the rev and load range and have only made timing adjustments to injector timing table 1, from 0 to 30 degs.
I know I need to increase the fuelling throughout the high load range, but so far, I’ve tried to keep away from the fuel VE tables to minimise the variables whilst getting the timing somewhere near correct.
So the best results for today:








I’m not sure if the AFR variation charts (second and fourth charts)add anything or not...

Anyhow, A pleasing day all round!

’77 Clubman build thread
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=618189

Siamese 5 port EFI testing
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=611675

Looking good.

You will need some precision on Injection Timing Table 1 to maximise the amount of fuel you can get in the outer cylinders.

You probably then want to start to optimise the Injection Timing Table 2 to minimise the time that the fuel sits in the port, if at all.

Personally, I would stick with one timing table, but you may find a solution that I could not.

EDIT: Also, why have you set it at start of pulse? When you come to fit the larger injectors it will all be wrong. If you set it up on mid-pulse the change will not make a significant difference.

Edited by Paul S on 3rd Apr, 2010.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."