Running rich at stock boost (9psi) No engine mods

C

cneculae

Member +
Hi guys
I have a 1992 4efte EP-82 that is stock at the moment.
I did a top end rebuild on it about a year ago. (Cleaned head, new valve stem seals, new head gasket, oil pump, rear main seal)
Since I put the engine back together I have installed a Wideband (After market Lambda Sensor) gauge from AEM.
And after I drove the car around I notice that when under boost (9 psi) I am running very rich (11.2) according to the gauge.
This only happens when its under boost. When I am cruising the gauge is between 14.1 and 15.

I don’t know why this is because I do not have any after market upgrades on the engine at all.

I checked the MAP sensor and its fine
I changed my stock Oxygen sensor last year
I changed my temperature sensor as well
The car idles at 750 RPM ( so im pretty sure there are no vacuum leak)

My timing is advanced by 8 degrees at the moment.

What could be causing it to run so rich?

Thanks

-Cristian-
 
T

triple j

Member +
i think the stock ecu runs rich, am not too sure but someone on here will no alot more, why is your timing advanced.
 
N

Nick@TD.co.uk

Registered Trader <a href="http://www.TuningD
Toyota ECUs run rich as a safety feature, 11.2:1 sounds not too bad for a stock ECU compared to some that we have seen!

Cheers

Mike Jones
Tuning Developments Ltd
 
C

cneculae

Member +
Ahh i see but the thing is im getting petrol in the oil.
After 500 miles the oil is black.
SOme guys here were talking about getting an adjustable Fuel pressure Regulator and turning downt he pressure a bit.

Also should i set my timing back to 0?
COuld that have some thing to do with it?
 
A

aidan

Member +
the black oil is down to carbon in the engine not petrol unless you can get the smell of petrol off it
 
Paddy

Paddy

Lifer
my car always ran rich with the standard ecu, i tried everything then fitted a jam racing ecu and it sorted it out perfectly :) before anything over .7 it felt like it lost power, then with the ecu, 1.0 boost was perfect
 
C

cneculae

Member +
Well i do smell petrol in the oil so it must be running a little rich.
Enough for the petrol to get past the rings and mix with the oil.

Thanks fot all the info guys.

So in conculsion can I use a adjustable fuel pressure regulator to turn down the pressure a bit and stop the engine from running so rich?

Or should i save some $ and but a piggy back system such as SAFC II and have it tuned and take out some of the fuel by a shop.
 
ramses974

ramses974

Member +
cneculae said:
Hi guys
I have a 1992 4efte EP-82 that is stock at the moment.
I did a top end rebuild on it about a year ago. (Cleaned head, new valve stem seals, new head gasket, oil pump, rear main seal)
Since I put the engine back together I have installed a Wideband (After market Lambda Sensor) gauge from AEM.
And after I drove the car around I notice that when under boost (9 psi) I am running very rich (11.2) according to the gauge.
This only happens when its under boost. When I am cruising the gauge is between 14.1 and 15.

I don’t know why this is because I do not have any after market upgrades on the engine at all.

I checked the MAP sensor and its fine
I changed my stock Oxygen sensor last year
I changed my temperature sensor as well
The car idles at 750 RPM ( so im pretty sure there are no vacuum leak)

My timing is advanced by 8 degrees at the moment.

What could be causing it to run so rich?

Thanks

-Cristian-
Click to expand...

Your AFR is good for a stock ECU...all TOYOTA ecu are runing rich ...some have an afr close to 10.5 ...nothing is wrong with you car
 
C

cneculae

Member +
Ok good to hear.
But why am i getting petrol in my oil.

Is it because my spark plugs could be fouled? or
Is it because my rings are worn?
 
A

AdamB

Member +
Could either be ignition related, ie they are not sparking the fuel and your getting bore wash or you have a poor cylinder seal. Do a compression test and check ignition components that are likely to wear. Spark plugs, HT leads, rotor arm, dis cap.
 
C

cneculae

Member +
Well the leads, dizzy cap and rotor arm are all new as well as the spork plugs.

I have not done a compression test yet but i will do that next.

ALso could i just fix this problem by instaling an Adjustable Fuel Pressure Regulator and turn the pressure down.
 
9

96v

Member +
lol, there is no problem with regards to your fueling/running rich mate, as said 11.2 on a stock ecu is good so why mess around with it?

The supposed smell of petrol in your oil will be coming from else where, do a compression test, post up results then we can move on from that :D
 
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