Race Engine Forum UK

ECU ISSUE FIXED TODAY!!!

As it turned out GC forum member Nik Osborne was right in pointing me at the direction of trigger wheel to sensor gap. I measured it and found gaps:

#1 - 1,1mm
#2 - 1,6mm
#3 - 1,1mm
#4 - 0,6mm

So the maximum allowed gap difference between adjacent teeth is 0,2mm and mine was 0,5mm! As this is not a small difference I decided to follow trough and try to exorcise the demons. I used a file to shorten the 3 teeth that had the gaps narrower. Installed back the trigger wheel, measured again, and a bit more filing later the gaps were all at 1,6mm +/- 0,05mm. Then I narrowed the gap to 0,9mm.

After a re-installing the auxiliary belt etc. I swapped the ECU to the OE one and fired her up. Everything started normally and the moody lady seemed happy to rev above the magic 2000 rpm mark where that illusive barrier lay beforehand. I reassembled the rest of the car, installed back the GC recommended spark plugs and went for a test drive. It looks like the problem is fixed! I got the car up to 5000 rpm with no problems. But as it was already dark the local roads became a popular meeting ground for deer, rabbits and other suicidal animals so I decided to stop with experiments for the day.

Thanks to everyone that helped with their advice! It remains a mystery why this gap would cause one ECU to fail and the other have no problem with it.

I still have a slight wobble in the pulley:

http://www.youtube.com/watch?v=OhCsWM2pzJM

Not really sure what to do with it but I might just have to let it be...

I will now raise the boost pressure to the 1 bar that it is suppose to be. I am currently still running it a 0,5 bar. I am thinking of installing a WB lambda. Any recommendations for a tight budget?

Well done, and just in time for the nice weather. I am definitely putting that one in my memory bank.
Enjoy the car, it's been good watching and very helpful in restoring mine.
Steve

After testing the car for additional 100km I concluded that the ECU is working well!

So next step will be raising the boost and to do that safely I ordered a kit from Innovate that includes a Wideband Lambda, Controler and a gauge. And unlike the last time that I measured the AFR at the exhaust end this will be installed properly at least for the time to tune the engine. After that I will probably take it out as I don't think that this modern looking LED gauge suits the car at all.

As there is no direct instructions where to mount the WB lambda I just chose a well accessible spot that suited me. The only thing the manual states is that it has to be mounted behind the turbo charger and before the catalytic converter (if it exists) and that it should not be mounted on a lower half of the exhaust pipe so that it doesn't get sprayed with condensation. I hope I picked a good spot as I really don't want to keep making holes in my down-pipe.

Generally narrowband sensors should be close to turbos, but widebands need to be a little further away (possibly 1 metre?) as they are far more sensitive to heat.

For a one off installation for a short period you might be ok but I'd have mounted it a little further back.

On 4th April 2012 you posted that you reversed the magnets in the rad fan to make it spin the correct way.

Mine is wired with a (fused) live and its the earth that gets switched for the 1st and 2nd stages. Is yours the same?
Steve

Hi Nobby,

thanks for your input I read the installation manual and the only thing I found in 'how to install' was that it should be on the upper half of the exhaust to minimize the splashing of the condensation against the hot probe. And that the temperature of the probe shouldn't exceed 500 degrees Celsius. I am trying to keep the car as original as possible so after it is set up i will remove the probe so this is temporary installation and I don't want to make any more holes into the downpipe. Over all distance from the engine head to the WB probe is about 50 cm.

I started lifting the boost and the first I only tightened the WG about 1-2mm as I didn't know what kind of a difference that will make. It was only about 0,1 bar difference so I bravely tightened it a lot more and now the car is boosting up to about 0,85 bar boost. This is a big difference in comparison to the 0,5 that I had before. It made me smile and forget I was driving around in a non air conditioned car, black and the outside temperature was 30 degrees.

The car now revs and pulls well up to about 5000 rpm. Above that it is still a bit reluctant. But it does only have 1800 km on the clock and the boost can go a bit higher still...

I tested the OE ECU and 2 modified chips that I have. The big difference between them is that since I have the fuel pressure raised about 10% over the original 3 bar the OE map is running a bit rich when at low revs and withouth boost. And the 2 modified maps I think need the fuel pressure raised about 20% to work properly as they are (at least IMHO) running a bit lean.

OE ECU:

-off boost cruising AFR 14,5
-slow acceleration AFR 13
-on boost AFR 11.5

Modified ECU :

-off boost cruising AFR 17
-slow acceleration AFR 14,5
-on boost AFR 11,8

Modified ECU2:

-off boost cruising AFR 15
-slow acceleration AFR 14,5
-on boost AFR 12

I would like to hear some comments on the AFRs' that I am getting. I will however measure the modified ECUs again when I turn up the fuel pressure to 3,5 bar.

A lot of work was done over the last few days...

Here are a few things I have also done but I didn't get a chance to publish!

Racking up test runs....

http://www.youtube.com/watch?v=OS4r-tHXQhY

Currently I am running the AFR @ 1bar boost around 12-12.5! I have the fuel pressure raised to about 3.6 bar and I now have a problem with the car when it is cold. It is running so rich it will not hold it's idle. I can set it to run OK if I unscrew the CO screw on the throttle body almost fully out, but then when it get's hot the idle is way too high. And if I get all the settings perfect when it's hot then it will start but I have to hold the throttle open and the engine running at at least 1500rpm to keep it from cutting out. And I get the same result with the OE ECU and with a modified map that was adapted for higher fuel pressure.

And I have all this problems since I changed one hose on the idle solenoid that was leaking...

Did a bit of tinkering around the car!

And I finally got around to changing the front bumper. Of course this is not a 2 hour job as I predicted. I have to fabricate the grill mesh, relocate the mounts and fix the mounting points for the fog lights...

I also found two spare front hubs which I will take apart, sand blast, powder coat and install new bearings. This way I will have the car on and off the ramp in a few hours and not loose 2 weeks of having the car off the wheels. I really made a mistake by buying cheap bearings the first time. I bought some "made in Germany" bearings that turned out to be made by "Optimal"... AVOID! I have later found out that a lot of people have bad experience with this make. Most have had failures in less than a year. Mine sounded strange from new and started oozing grease after 1000km!

I will also have to fix one of the spare wheel hubs that was abused a bit too long and started turning in the bearing and is now too loose. So the surface will have to be "diamond cut". Not sure how this process is officially called but basically a cross pattern is pressed into the surface and this causes the metal to "swell up" and you get back the missing tenth of a millimeter.

Just a short video of the start up sound...

http://www.youtube.com/watch?v=bHlqcHvtG5E

It's still over fueling when the engine is cold. But at the moment it is just too hot outside to work... About 36°C in the shade.