Hi all. It’s been a while since my last report.
I recently went on the VMCi economy outing. The car did not perform very well. It was way down on torque in the low RPM’s below 3000RPM. In fact for most of the time I followed a lovely couple in their original 998cc clubman and I had some trouble keeping up with them on the steeper hills. My thoughts turned to pushing out my 6′ 97kg 15yo son, but thoughts of facing his mother deterred me!
Today I had a look at the EFI and as surmised in my previous posts the fuel regulator is not doing it’s job; its allowing the pressure to jump all over the place. As well the gauge is getting stuck and not returning to zero (it most probably bashed it self to death).
I decided I would put the SU bell back on returning the car to carb with ignition only control from the ECU. One of the reasons for doing this was to see how the car goes back on carb and to see if it is fuel related.
Well one thing it proved, was yes the FPR is rooted (Aussie for ‘stuffed’ for OS readers). I lowered the OP pressure to around 3PSI, but after a while the pressure jumped to around 16PSI which you guessed it; flooded the engine to such an extend it became hydro locked. End of experiment.
I’m really not too happy with the fuelling side of this conversion, but the difference having programmable ignition was very noticeable, especially in the lower RPM ranges. Due to this I’m considering returning the car to ‘standard’ which is quite easy to do. I would like to be able to use and enjoy the car with out worrying about VE maps AF ratios etc. etc….
I feel a little bit disappointed that this project has not been a total success, but maybe it has; the original purpose of this project was to help me get out of a period of major depression and to re-join the work force, (achieved), and to learn more about EFI also achieved.
As to what the future holds in store for this car….. stay tuned! Hint ‘sparks’.
Thanks all to those who have been following this thread.
Today I had a look at a few things to do with the tune of the EFI.
- I never had time (unless I did but have forgotten) to find out how accurate my dead time settings were after my previous static testing. Well, one way to test if you have the dead time right is to tell the ECU to squirt only 2 squirts per cycle (I’m currently running 4 per cycle), and see if the engine idles smoothly and at the same A/F ratio (14.0:1 is what it is set at). When I first did the change, I thought I’d done something wrong, as the idle and AF ratio stayed the same. I then noticed that the injection pulse width had nearly doubled when on the 2 squirts, this meant that the dead time was spot on! Yeah! On the MegaSquirt extra forums they constantly say to get your dead times right.
- I and ran the auto tune program, whilst driving around the local area and down to Werribee South for lunch by the sea. Initially it was a bit reluctant to rev out past 4000RPM, but soon no problems going to 6500 RPM (I don’t like taking past 6K, but I just had to see if it would go there!) and AF correct. The VE table now looks like it should, especially at the lower load points, also it has less peak and troughs. I need to do a bit of further tuning, mainly in the higher load/RPM areas, but It’s quite drivable as is. Wish there was more hills around here!
- In the process of tuning the car, I checked and set the fuel pressure to 14.7PSI (same as the Rover SPI… 1Bar). I noticed that above 11PSI or so, that the needle of the fuel gauge started to shake by a bout 1.5 – 2 PSI. I have a feeling that the SPI pump is a bit up the shit, or maybe it’s the fuel pressure regulator. Either way it’s about time I got the fuel pressure sensor screwed in and wired up to the MegaSquirt MSX board that I have recently purchased. The MSX board has additional A/D inputs and digital I/O’s needed for this and when I go the MAF route. The ability to monitor the fuel pressure will allow me to see if I have sufficient pressure/volume.
Cheers, all comments, criticism welcome!
Nothing much really to report.
I took her to work on both days this weekend. She’s just purring along and over the last 320km she achieved better than 53MPG!
One thing I have noticed is that she backfires when starting. This has only happened since the upgrade from the MegaSquirt II to III hardware upgrade. I did see a mention on the MegaSquirt Extra forum from another user that they were having backfires on the latest firmware (same as I have). I think I’ll leave alone until the firmware goes production ready.
I’ve also put the TunerStudio software on my Netbook so I can use it rather than my MacBook Air. Reason being is that the Netbook fits really well in the L/H dash and the Mac doesn’t.
The first 230k’s were the trip I took to Marysville, so very little stop and start, the last 100k’s just local and highway trips to work. I’m very impressed!
One observation is the new 14point7 wide-band O2 sensor seems to be a lot quicker in reacting to AFR changes compared to my TechEdge. This will obviously (I think) help TunerStudio tune the VE table more accurately.
I’ve also just tested the Netbook to make sure it can connect to the ECU. It does, both by Bluetooth (I can fit an RS-232 to Bluetooth adapter on the ECU), and USB.
If I had multiple injectors running sequential injection, Megasquirt can also progressively shutdown the injectors for a smoother transition. I don’t really feel the cutoff or reengagement, maybe because the 1310 is not the smoothest engine?
My Renault has this feature, and I can feel the reengagement sometimes. I also get 6.4l/100km (37MPG) combined city/highway.
I’ll try to get some comparative MPG readings.