as i understand it, the ecm shuts off the injectors when the throttle is closed above 1100 rpm and you're coasting. how come my scangauge still shows upwards of .4gph depending on rpm? does anyone else's show 0gph?

btw, just got the SGII and :thmsup:

since no one else will reply....

now why I refrained up until now. I'm not the nicest person here, so don't take offence......


A............. even if the injectors aren't squirting, fuel is flowing back to the tank on the return side of the fuel system via the fuel pressure regulator, thus there will always be some flow. the exception is returnless fuel systems, which you don't have I'd bet.


B............... get the silly toy out of your car, it's apparently just making you paranoid. some things you do not need to watch or think about while you're driving.


no hard feelings, right? :lmao:

I don't necessarily trust aftermarket scan tools data readings.
Many do have glitches that are in the software, I've run into this many times. Having false data is sometimes worse than none.

The '99 has a returnless system. Actually all the gen 7 (correcting my mistyping) v6s have a single feed line to the engine. I believe the same is true for the 4s as well. The return is in the delivery module in the tank, where the pressure regulator is. 6s have returns on both motors

If you see injector pulse width at zero, there is no fuel delivered to the cylinders.

Stevel wrote.

>>>now why I refrained up until now. I'm not the nicest person here, so don't take offence......<<<<

That's not true Steve, you have always been very polite and helpfull with any problems I have needed help with.. Thank you for that. :) :thmsup:
.

I don't necessarily trust aftermarket scan tools data readings.
Many do have glitches that are in the software, I've run into this many times. Having false data is sometimes worse than none.

The '99 has a returnless system. Actually all the gen 6 v6s have a single feed line to the engine. The return is in the delivery module in the tank, where the pressure regulator is.

If you see injector pulse width at zero, there is no fuel delivered to the cylinders.

Honda used returnless systems that long ago????? wow, the germans are further behind than I though......

hi steve
check out my corrected post above. major brain-fart there.

I'm so used to the gen 7s now, I forget the simple stuff sometimes.

What I don't get, is why they all haven't gone returnless, the whole point was to simplify the system, and to reduce fuel vapor emissions by keeping the tank fuel cooler.

hi steve
check out my corrected post above. major brain-fart there.

I'm so used to the gen 7s now, I forget the simple stuff sometimes.

What I don't get, is why they all haven't gone returnless, the whole point was to simplify the system, and to reduce fuel vapor emissions by keeping the tank fuel cooler.

I don't work on enough different cars to know who does what, but every audi and porsche I can think of at this point is returnless. I think at least, but I could be missing one engine....

on the 996 turbo, porsche added a fuel cooler via the a/c to cool the fuel before it returned to the tank... not sure why they thought that was the easy way to deal with vapor emissions, but........ :lmao:

in my Helm's fuel system schematic there is definitely a return. and the less the injectors are using, the more fuel gets returned. i just dont see anywhere in the system some kind of meter so i wonder how it knows the fuel flow or if it bases it off what it 'thinks' it should be under current RPM, MAP etc. you're right though stevel and fredsvt, sometimes its TMI, sometimes.. i'd like a big ol graphing scantool but this was cheap and has good features- hopefully it doesnt lie too much. just made me wonder if the TPS is faulty making it think throttle isnt shut. the way it drives makes me think the injectors are cutting off- when i decelerate thru 1100 the tach bumps up above momentarily like it just got fuel. but i havent had anything with a slushbox for years so maybe im imagining things. also if anyone else has a scangauge and can confirm or deny coasting fuel flow- speak!

in my Helm's fuel system schematic there is definitely a return. and the less the injectors are using, the more fuel gets returned. i just dont see anywhere in the system some kind of meter so i wonder how it knows the fuel flow or if it bases it off what it 'thinks' it should be under current RPM, MAP etc. you're right though stevel and fredsvt, sometimes its TMI, sometimes.. i'd like a big ol graphing scantool but this was cheap and has good features- hopefully it doesnt lie too much. just made me wonder if the TPS is faulty making it think throttle isnt shut. the way it drives makes me think the injectors are cutting off- when i decelerate thru 1100 the tach bumps up above momentarily like it just got fuel. but i havent had anything with a slushbox for years so maybe im imagining things. also if anyone else has a scangauge and can confirm or deny coasting fuel flow- speak!

it's most likely calculated, my nav shows something I think is similar to what you are talking about. and what you feel as you decelerate through 1100 rpm could just be the torque converter unlocking, or the transmission shifting out of second gear preparing for first if you are coming to a stop....... you won't feel the injectors come on in that situation......

it's most likely calculated

that makes sense. don't know how it would know otherwise. thanks for satisfying my curiosity- most of the time it gets me in trouble:paranoid: