Engine is adding to much fuel

cre · 06-23-2011, 01:16 AM

How have you determined it's running excessively rich?

No, the stock FPR is not adjustable and adjusting the pressure would just be hiding an existing problem.

Is it rich at idle? While driving? At WOT? And again... how do you know its running rich.

What else have you tested? Coolant sensor? Plug wires? Coil(s)?

BTW, the SAFC setting will need to be tailored to your specific vehicle. If it's a stock system you're usually wasting your time but you'll still want to be tuning it on a dyno. With the SAFC installed and all setting at zero there should be NO difference in how the engine operates.

Nathaninwa · 06-23-2011, 01:34 AM

Ah yes, the coolant temp sensor. My supra had a wierd stumble under boost and for the life me I could not get it figured out...ran great other wise in cruise, and minimul boost....turned out the coolent temp sender was almost corroded to the point it was about to fall off. Changed sensor and pigtail, problem solved.

cre · 06-23-2011, 01:39 AM

There's also the potential of a boost leak.

Conga1991 · 06-23-2011, 06:32 PM

To Cre- When I start my car I would have to have my foot on the accelerator and keep pumping it til I got it to idle high and whenever I let off the gas it will idle low then stumble. buut when I do try to drive it, there is no power and it's idling pretty high and it wouldnt go past 10mph.

Conga1991 · 06-25-2011, 06:05 PM

Didn't mean to put idle. what I was trying to say is, When I try turning my engine over I have to put my foot on the gas so it will actually get up to higher rpms but even then I have to pump it. It seems like there are a couple cylinders that aren't sparking either.

When I pulled the spark plugs they were extremely black, so I tried cleaning them with carb cleaner and use sand paper to scrape most of it off, that's what a mechanic told me to do, I put them back in and still did the same thing and then they didnt want to spark at all. The engine just cranks over.

Nathaninwa · 06-25-2011, 06:46 PM

Look at the coolant temp first....either get the ohms it should be at a given temp and test, or see about getting a used one for testing. On a cold motor you dont even need to isntall the sensor, just unplug yours and plug the other one in. It will be ambient, very close to water at that point. See how it starts. Wifes legend was like this...nothing but crank, need starting fluid to get going. Bought the 10 dollar sensor and did just that, fired right up, so I installed it.

cre · 06-25-2011, 08:24 PM

Actually you should pull the sensor and use a pot of water on the stove with a tiny bit of coolant or salt (to increase the boiling point) and test through the full range. NTC and PTC based sensors can shift over time and may appear fine at one temp but get further off very quickly as the temp changes. Use a GOOD thermometer to monitor the water temp.

The same thing goes for measuring rheostats (TPS and the VAFM on the GE)... should be a smooth transition, this is easiest to measure with voltage supplied though and not by the OHM readings. Well, same thing as in shifted values, not boiling them in water.

06-23-2011, 01:16 AM	#1
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	How have you determined it's running excessively rich? No, the stock FPR is not adjustable and adjusting the pressure would just be hiding an existing problem. Is it rich at idle? While driving? At WOT? And again... how do you know its running rich. What else have you tested? Coolant sensor? Plug wires? Coil(s)? BTW, the SAFC setting will need to be tailored to your specific vehicle. If it's a stock system you're usually wasting your time but you'll still want to be tuning it on a dyno. With the SAFC installed and all setting at zero there should be NO difference in how the engine operates. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

06-23-2011, 01:39 AM	#3
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	There's also the potential of a boost leak. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

06-25-2011, 08:24 PM	#7
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Actually you should pull the sensor and use a pot of water on the stove with a tiny bit of coolant or salt (to increase the boiling point) and test through the full range. NTC and PTC based sensors can shift over time and may appear fine at one temp but get further off very quickly as the temp changes. Use a GOOD thermometer to monitor the water temp. The same thing goes for measuring rheostats (TPS and the VAFM on the GE)... should be a smooth transition, this is easiest to measure with voltage supplied though and not by the OHM readings. Well, same thing as in shifted values, not boiling them in water. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

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06-23-2011, 01:34 AM	#2
Nathaninwa Intake Join Date: Jun 2011 Location: Aberdeen, WA Posts: 43	Ah yes, the coolant temp sensor. My supra had a wierd stumble under boost and for the life me I could not get it figured out...ran great other wise in cruise, and minimul boost....turned out the coolent temp sender was almost corroded to the point it was about to fall off. Changed sensor and pigtail, problem solved.

06-23-2011, 06:32 PM	#4
Conga1991 3" Exhaust Join Date: Jun 2009 Location: Avondale, AZ Posts: 169	To Cre- When I start my car I would have to have my foot on the accelerator and keep pumping it til I got it to idle high and whenever I let off the gas it will idle low then stumble. buut when I do try to drive it, there is no power and it's idling pretty high and it wouldnt go past 10mph.

06-25-2011, 06:05 PM	#5
Conga1991 3" Exhaust Join Date: Jun 2009 Location: Avondale, AZ Posts: 169	Didn't mean to put idle. what I was trying to say is, When I try turning my engine over I have to put my foot on the gas so it will actually get up to higher rpms but even then I have to pump it. It seems like there are a couple cylinders that aren't sparking either. When I pulled the spark plugs they were extremely black, so I tried cleaning them with carb cleaner and use sand paper to scrape most of it off, that's what a mechanic told me to do, I put them back in and still did the same thing and then they didnt want to spark at all. The engine just cranks over.

06-25-2011, 06:46 PM	#6
Nathaninwa Intake Join Date: Jun 2011 Location: Aberdeen, WA Posts: 43	Look at the coolant temp first....either get the ohms it should be at a given temp and test, or see about getting a used one for testing. On a cold motor you dont even need to isntall the sensor, just unplug yours and plug the other one in. It will be ambient, very close to water at that point. See how it starts. Wifes legend was like this...nothing but crank, need starting fluid to get going. Bought the 10 dollar sensor and did just that, fired right up, so I installed it.