scottyMIz Posted September 4, 2001 Share Posted September 4, 2001 Thanks BLKMGK it made sense.I was just wondering if it was enough fuel?It does raise and lower according to the boost pressure and vacuum.So i know that's right.The fpr is a different one the cruched one just had too much pressure it would put out black smoke from idle all the way to redline kinda embarrising But now it's much better has a hell of alot more power especially in the higher rpm. Quote Link to comment Share on other sites More sharing options...
TimZ Posted September 5, 2001 Share Posted September 5, 2001 That sounds alot better. Do you have some method of checking the air to fuel ratio through the gears? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted September 5, 2001 Share Posted September 5, 2001 Sounds like a A/F meter/gauge might be warranted if you really want to see what your mixture is doing. Regards, Lone Quote Link to comment Share on other sites More sharing options...
scottyMIz Posted September 5, 2001 Author Share Posted September 5, 2001 No tim i don't but i can check if anyone knows what the volt reading is for the O2 sensor on lean and rich mixtures?I can't afford a a/f meter right now unless someone has one for cheap.I think the ones i saw run like 200 bucks That's a bit pricy for me right now. Quote Link to comment Share on other sites More sharing options...
Drax240z Posted September 5, 2001 Share Posted September 5, 2001 Scottie search the site, I am not sure where exactly but evan purple posted a link on how to make your own a/f meter. You could probably make it for around $15 and use your existing o2 sensor. I bought mine from SDS (very nice too) for somewhere around $75. Quote Link to comment Share on other sites More sharing options...
scottyMIz Posted September 5, 2001 Author Share Posted September 5, 2001 I got the injectors in and it runs great.I checked the fuel pressure and at idle it runs at 30 psi and under boost at 16 psi it goes up to 50 psi and holds all the way.I was wondering if this is good or bad?But it goes up gradually thru the gears i'm guessing as the boost pressure in each gear goes up the higher the fuel pressure.It has great power all the way thru every gear it doesn't fall on it's face now when it gets up in the rpm range.I love it anyone looking for the same injectors the guy has 12 more and is looking to get rid of them.If you want i can hook you up with his email. Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted September 5, 2001 Share Posted September 5, 2001 Fuel pressure needs to rise as boost rises and needs to fall as vacuum increases. Normally folks shoot for a 1:1 risefall and it sounds like you're pretty close to that. Is this the unit you crushed or no? The reason for this raising and lowering of pressure is that boost will try to push the fuel back down the pipe and vacuum will try to suck it out. By raising and lowering the pressure you're actually pretty much keeping the fuel supply out of the picture as a variable. This makes tuning simpler as you don't have to worry about what the fuel pressurecapacity of the fuel injectors is going to be - it ends up being what the injector is rated for. Does that make sense to ya'? Kind of hard to explain but it's normal for your car IMO. Some cars will band-aid fuel pressure in order to get more fuel under boost. This is what that silly FMU does on blower cars - instead of 1:1 with boost it will do say 2:1 or even higher. Instead of doing the fuel "correctly" with the ECU they raise fuel pressure artificially to richen the mixture. Bleah! The ECU is none the wiser since it's running open loop at WOT but the fuel pump and injectors sure feel the burn They will often times band-aid the ignition too Frankly, this is the sort of silly garbage that got me interested in aftermarket EFI... Quote Link to comment Share on other sites More sharing options...
Mike C Posted September 5, 2001 Share Posted September 5, 2001 Cyberdyne has an AF meter that will use your O2 sensor for $30 from Summit. (I think they had a name change, but the LED gauges in the catalog) Quote Link to comment Share on other sites More sharing options...
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