Car Running Rich, Its Standard!

[RBLUV]

well story goes, took my car to epa inspection, failed because i was running too rich,

mods are as follows:

RB20DET

greddy front mount

3" front and dump

bosch 040

EVERYTHING else is standard

i replaced the o2 sensor with another 2nd hand one but was still shooting petrol out the exhaust

anyone else think of anything?

i need help as im out of ideas and its not worth going to a tuner to tune down the car so

any help appreciated

Edited July 14, 2008 by HI2U

[GTR-32U]

could the possibilty exist that the O2 sensor you installed could have been in worse condition than the original one ? I would only go brand new

[quiksta]

With the modifications you've performed your car is not standard, therefore it will run rich. If you want to rectify your problem you'll need to either get a piggyback, aftermarket ecu or remap your standard ecu.

[AKW]

Apexi SAFC or remap man... mine did this shit as well. =(

Well, does it... don't have mine on there yet.

[AndyD]

I was just reading up on O2 sensors in another part of this forum cant remember where but apprarently you have to do a ecu reset after installing/changing a new sensor just disconnect the battery for a while then take it for a drive. Dont qoute me on this but do your own search for o2 sensors.

[nizmonut]

that is correct, the ecu has a memory for the afm, o2, tps, and cas,

if any of these are changed while the ecu is plugged in it will not attempt to alter any settings.

un plug the o2 sensor, then unhook the battery, stand on the brake pedal for a good minute or with the key in the ON position so as to discharge any electrical current that is still in the system(works similar to putting a security coded car stereo in the freezer over night(loses it memory).

plug the o2 sensor back in then the battery, the ecu will relearn all the signals and ignition timing and frequencey, it will run a little rough for the first 5 minutes while the ecu remaps itself, the ecu has a base map already programmed however the map is intervalled by 500 rpm and the ecu fills in the rest.

[AndyD]

that is correct

Yay i actually retained some useful information

[_x_FiReStOrM_x_]

Its because of the 040. The 040 is a higher pressure pump than standard, so now your base rail pressure will be bumped up a fair bit. The way to get around this, is you need to knock the rail pressure back down to standard (or less in some cases). Get an adjustable fuel pressure reg and fuel pressure gauge; and either knock the base pressure back down to factory specs for an easy fix, or better yet find a good tuner to check AFR's with a wideband/lambda and set the pressure accordingly.

[InterCooL]

your modification to the intercooler is another reason why its running rich. it mucks up the tune and its very noticable.

my car only has a pod / fmic / exhaust and it runs AF's down to the 9.0's!

but there is an long thread by someone on here which said to have the right emissions (NOx etc) you actually had to run rich.... food for thought

[R31Nismoid]

I bet you have a stuffed fuel regulator

@ idle, if you rev it and can see a bit of a fuel cloud, bets on the fuel reg.

Get a pressure gauge, hook it up, take it for a quick drive and i bet it'll be all over the place

[R31Nismoid]

Its because of the 040. The 040 is a higher pressure pump than standard, so now your base rail pressure will be bumped up a fair bit. The way to get around this, is you need to knock the rail pressure back down to standard (or less in some cases). Get an adjustable fuel pressure reg and fuel pressure gauge; and either knock the base pressure back down to factory specs for an easy fix, or better yet find a good tuner to check AFR's with a wideband/lambda and set the pressure accordingly.

ummm no thats not the case at all.

The fuel reg is a fuel reg, it regulates the fuel. It does not matter WHAT pump you have behind it, the factory fuel reg will hold the pressure (as long as its working)

[AKW]

Does an ECR33 come standard with a fuel regulator in the bay? o.O;; If so, where?

[Adriano]

Ive never heard as much wrong advice in a thread. Your mods should not effect your A/F ratio. There is something wrong. As nismiod said fuel reg, or possibly dirty afm(although that usually makes it lean) Do a diagnostic search, reset the ecu, comp test with new spark plugs, and check fuel pressure. Also make sure your IC piping doesn't have any leaks(although that will also make it lean at idle, rich on boost)

[RBLUV]

thanks for the help guys, will give the ecu a reset tonight and check fuel pressure reg

[_x_FiReStOrM_x_]

ummm no thats not the case at all.

The fuel reg is a fuel reg, it regulates the fuel. It does not matter WHAT pump you have behind it, the factory fuel reg will hold the pressure (as long as its working)

If the aftermarket pump is a higher pressure than the stock one(lets disregard flow rates for the moment, just concentrate on pressure), then the rail pressure will be higher. The pressure reg is vacuum controlled, therefore it does not know to compensate for higher pump pressure. It can only compensate for engine load (vacuum/mani pressure).

[BAMR33]

well story goes, took my car to epa inspection, failed because i was running too rich,

mods are as follows:

RB20DET

greddy front mount

3" front and dump

bosch 040

EVERYTHING else is standard

i replaced the o2 sensor with another 2nd hand one but was still shooting petrol out the exhaust

anyone else think of anything?

i need help as im out of ideas and its not worth going to a tuner to tune down the car so

any help appreciated

I doubt petrol was coming out the exhaust, probably just condensation.

The first thing you should do is check ignition timing, the spark has a big influence on how well the fuel burns.

[Adriano]

If the aftermarket pump is a higher pressure than the stock one(lets disregard flow rates for the moment, just concentrate on pressure), then the rail pressure will be higher. The pressure reg is vacuum controlled, therefore it does not know to compensate for higher pump pressure. It can only compensate for engine load (vacuum/mani pressure).

NO, the pressure reg holds pressure to a preset amount above manifold pressure, regardless of the pump (as long as teh pump can keep up)

[_x_FiReStOrM_x_]

NO, the pressure reg holds pressure to a preset amount above manifold pressure, regardless of the pump (as long as teh pump can keep up)

Lol fair enough mate you could be right. Its just, the way i thought of it was; if the pump is too high pressure and the reg is trying to control the base pressure by spring, at high pressure the stock reg cannot return the amount of fuel required of it to maintain its preset pressure, so it becomes a restriction. And seeing as it is now a restriction, it causes the rail pressure to rise. You could be right, but thats just the way that i see it... seeing as the 040 is a 6.5bar pump, i would have imagined it would be a significant rise over stock.