Car bogs under light load... Fuel pump dying?

[Nemasys]

I have a strange problem with my car.

When i start the engine and let it idle it works perfectly fine.

When i hold the throttle down slightly the revs climb slowly then at 2.5-3k rpm the car bogs out pretty badly.

Under heavy load or WOT it runs perfectly fine. It only bogs out under low rpm, low load conditions....

I've got new sparks plugs in there and that didn't fix the issue, the spark is good also.

Any ideas? Clogged fuel filter? Pump slowly dying??

[petrified.rabbit]

this is on the turbo car? it could be "programming" or a dead spot in the boost?

[Nemasys]

theres no boost at those engine load levels

it even does this on the bone stock ecu, i tried running it on megasquirt and it does the same thing

at 1st i thought it might be the injectors but its not, then i changed the plugs and it ran ok for like 15 minutes then it started bogging out again

could the spark plug gap be the culprit also?

[petrified.rabbit]

typically, if it was plugs or the fuel pump it would be worse at full throttle as well.

if its 15 minutes of good running with new plugs it might have too much gas and not enough air is getting sucked through the turbo.

it could also be a preset timing advance/retardation that no longer matches your set up, the variable runner manifold opening/closng too slowly(do you still have that?) the lack of boost.. (turbo lag :P ) since you have a lot of air needing sucked through the turbo instead of the turbo pushing it in..

do you have an o2 sensor gauge? or a scanner that will read your oem o2?

[Nemasys]

when i pulled the old plugs they were kinda greyish at the ends

the turbo spools almost instanstly and pushes air in the engine, it doesnt create any boost but the engine isnt starving for air either

on the stock ecu, the wideband reads perfect afr's until it bogs out it gets ultra lean

on the megasquirt i tried pushing more fuel in the engine and the wideband reads rich conditions but it still bogs out, if i mash the pedal to the floor it pulls like hell and works perfectly well

[Nemasys]

the 2.0 doesnt have variable intake runners, and i have the stock primary o2 sensor in place

[ontarian_frog]

Going way lean would bog it down. For some reason the ECU might be cutting the injectors off? You should monitor the TPS and see if if has a dead spot.

[petrified.rabbit]

what did you do for the map sensor? that would control fuel rate and be directly affected by this..

[Nemasys]

map sensor is useless when using megasquirt because the unit has full control over the injectors regardless of anything, yet it still bucks heavily on light throttle, even if the fuel is super rich

the map sensor works fine else id get erratic fuel levels on the stock ecu, the tps also works good

[petrified.rabbit]

ok, my suggestion is to spend the $35 on a fuel pressure gauge for the rail, you might have an issue if you have one with a check valve (tester). but if you can read pressure and it is dropping during the bogging, you ned to check the fuel system.

i do have a question about the megasquirt, most of the megasquirt systems i used had a map sensor to help control fuel, how is yours set up?

sinc your 2.0 is different than the typical aveo, do you have a knock sensor, or anything like that that might cut fuel as well? if the timing isnt matching 100% and the engine senses knocking, it will cut fuel to prevent damage.

im trying to think of what else it might be.