Paso 750 MegaSquirt
Posted: Sun Jun 24, 2007 3:44 pm
This seasons project!
I wanted to see if I could get better fuel economy/throttle response and decided to change the carbs to a fuel injection system.
A colleague at work has built a car from scratch with MegaSquirt EFI. That sounded like a nice challange. After checkin the http://www.megasquirt.info/ I bought a kit and assembled it. There were a couple of other things to investigate in also, like throttle bodies (got a set from a ST2, thanks Jon!!), sensors, fuel stuff, etc...
Before I removed the carbs, I got the Paso on a dynorun. It has a big dip in the low-midrange. Hopefully the injection system can eliminate this a little. The engine needs a big service also. But the service have to wait a while.
The assembly of the box went fine. It is possible to control both ignition and fuel with the MegaSquirt. It is recommended to start with fuel only, which I did. The ignition part is a future project.
Put the throttle bodies to the Paso engine was much more difficult. I got the inlets together with the throttle bodie, but it was NOT bolt on. Same distance for the bolts though, luckily. After modification/new inlet rubber I got the bodies to fit the engine.
Next problem: Where shall I put the EFI box? It shall be a place where it is quite good protected from water, so somehow I had the get it under the saddle. Move all old electric stuff to the sides and put the EFIbox there instead. The box is well protected under the saddle.
At late spring time everything was in place and it was time to start the engine.
No success, stone dead!! check the EFIbox: ignition, injection trigger etc.. was ok.
Fuel? Not ok I guessed. I thought the Pasu fuelpump was enough. It was not strong enough. Search for a fuelpump started and some weeks passed. Found one close from a 996. Problem, it is internal. I needed an external. A local mechanicshop made me an adaptor, two actually. One for the pump and one for the fuel pressure regulator.
Connected the pump and pressure regulator. Still it wouldn't start. What now can I change? The software? Yes, the initial settings for start and warmup. Very frustrating work started, but at the end I got it to start.
Idles well at 10-1100 rpm now. Little tricky to start though.
But it did not run well, way too much fuel. It missfired a lot in a 10km run, stalled twice. But I got home.
After leaning the fuel map with 25%!! all over the engine runs good enough to be accepted.
Today I went for a 30km ride without stalls. A few missfires is acceptable. Minor problems that can be fixed.
Now the finalizing mapping starts with O2/lambda sensor logging.
I'm back on road again.
Some pictures @ http://alltomingenting.no-ip.info/galle ... Name=ducce
//Anders
I wanted to see if I could get better fuel economy/throttle response and decided to change the carbs to a fuel injection system.
A colleague at work has built a car from scratch with MegaSquirt EFI. That sounded like a nice challange. After checkin the http://www.megasquirt.info/ I bought a kit and assembled it. There were a couple of other things to investigate in also, like throttle bodies (got a set from a ST2, thanks Jon!!), sensors, fuel stuff, etc...
Before I removed the carbs, I got the Paso on a dynorun. It has a big dip in the low-midrange. Hopefully the injection system can eliminate this a little. The engine needs a big service also. But the service have to wait a while.
The assembly of the box went fine. It is possible to control both ignition and fuel with the MegaSquirt. It is recommended to start with fuel only, which I did. The ignition part is a future project.
Put the throttle bodies to the Paso engine was much more difficult. I got the inlets together with the throttle bodie, but it was NOT bolt on. Same distance for the bolts though, luckily. After modification/new inlet rubber I got the bodies to fit the engine.
Next problem: Where shall I put the EFI box? It shall be a place where it is quite good protected from water, so somehow I had the get it under the saddle. Move all old electric stuff to the sides and put the EFIbox there instead. The box is well protected under the saddle.
At late spring time everything was in place and it was time to start the engine.
No success, stone dead!! check the EFIbox: ignition, injection trigger etc.. was ok.
Fuel? Not ok I guessed. I thought the Pasu fuelpump was enough. It was not strong enough. Search for a fuelpump started and some weeks passed. Found one close from a 996. Problem, it is internal. I needed an external. A local mechanicshop made me an adaptor, two actually. One for the pump and one for the fuel pressure regulator.
Connected the pump and pressure regulator. Still it wouldn't start. What now can I change? The software? Yes, the initial settings for start and warmup. Very frustrating work started, but at the end I got it to start.
Idles well at 10-1100 rpm now. Little tricky to start though.
But it did not run well, way too much fuel. It missfired a lot in a 10km run, stalled twice. But I got home.
After leaning the fuel map with 25%!! all over the engine runs good enough to be accepted.
Today I went for a 30km ride without stalls. A few missfires is acceptable. Minor problems that can be fixed.
Now the finalizing mapping starts with O2/lambda sensor logging.
I'm back on road again.
Some pictures @ http://alltomingenting.no-ip.info/galle ... Name=ducce
//Anders