Running rich ?
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Running rich ?
Probably been posted before but couldn't find it.
My 89 F150 EFI 5ltr uses way too much fuel and the exhaust pipe even smells of fuel when it isn't running. Have replaced fuel resevoir before fuel pump and also the pressure regulator on the rails. Fuel pressure seems to be normal also. Black fuel smoke when I put the boot in.
Q. If the engine is getting too much fuel, would it be more likely to be the injectors are playing up, or the pump itself is pumping too much?
My 89 F150 EFI 5ltr uses way too much fuel and the exhaust pipe even smells of fuel when it isn't running. Have replaced fuel resevoir before fuel pump and also the pressure regulator on the rails. Fuel pressure seems to be normal also. Black fuel smoke when I put the boot in.
Q. If the engine is getting too much fuel, would it be more likely to be the injectors are playing up, or the pump itself is pumping too much?
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From: Easton,Ks
Originally Posted by monarokid
Q. If the engine is getting too much fuel, would it be more likely to be the injectors are playing up, or the pump itself is pumping too much?
If the fuel pressures are normal after you check the pressure as chrono4 said you might have a bad TPS or ECT sensor. Normal fuel pressure will be 33-34 PSI at idle and 40-43 PSI WOT.
After you fix the problem you will need to clean the O2 sensors.
ECT - Engine Coolant Temperature sensor
TPS - Throttle Position Sensor
WOT - Wide Open Throttle
Last edited by subford; Aug 26, 2007 at 09:11 AM.
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Originally Posted by subford
The pump can not pump too much fuel.
If the fuel pressures are normal after you check the pressure as chrono4 said you might have a bad TPS or ECT sensor. Normal fuel pressure will be 33-34 PSI at idle and 40-43 PSI WOT.
After you fix the problem you will need to clean the O2 sensors.
If the fuel pressures are normal after you check the pressure as chrono4 said you might have a bad TPS or ECT sensor. Normal fuel pressure will be 33-34 PSI at idle and 40-43 PSI WOT.
After you fix the problem you will need to clean the O2 sensors.
Geez how I miss the old carby'd V8's.
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From: The dark carnival
Originally Posted by monarokid
I have noticed that the temp guage hardly moves at all. Even when truck's been running for 1/2 an hour and it has a new thermostat too. So the coolant temp sensor has that much of an impact on fuel delivery ????
Geez how I miss the old carby'd V8's.
Geez how I miss the old carby'd V8's.
Opertaing temp has plenty to do with the fuel injector pulse width as calculated by the EEC.
Based on the fact that your gauge is telling you that the motor is not getting up to temp (unless I am misunderstanding you), you have a new thermostat in, and you are running rich, I would guess that the t-stat is not the correct one, stuck open or something along those lines. Do you have a laser thermomter? I would start taking some temp readings to see what temp the coolant is really at after about 1/2 hour of idling. If you are really not getting up to temp, then you are probably never reaching closed loop and that would explain you gas guzzling situation. Lastly, if the ETC is bad and it is telling the EEC that the motor is cool, then the pulse width will be calculated accordingly and the MPG will be down. This could also prevent the computor from reaching closed loop. But since your guage is reading low, I would look at the temp of the coolant as opposed to the signal that the ETC is sending to the EEC.
Last edited by eco; Aug 27, 2007 at 04:33 AM.
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From: Ottawa, Ontario
The sensors are the only input the computer has to tell it how the engine is running, and if one or more of these are giving it bad information, then the computer will inject to much fuel. Has the check engine light ever been on? I so go to fordfuelinjection.com and learn how to run a diagnostic test(ie:read the codes).
The dash temp gauge is not connected to the EFI system and uses a seperate sensor. It is located near the front drivers side lower intake, it's about the size of a dime and the wire pushes onto a stud on the top.
The dash temp gauge is not connected to the EFI system and uses a seperate sensor. It is located near the front drivers side lower intake, it's about the size of a dime and the wire pushes onto a stud on the top.
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Originally Posted by eco
Based on the fact that your gauge is telling you that the motor is not getting up to temp (unless I am misunderstanding you), you have a new thermostat in, and you are running rich, I would guess that the t-stat is not the correct one, stuck open or something along those lines. Do you have a laser thermomter? I would start taking some temp readings to see what temp the coolant is really at after about 1/2 hour of idling. If you are really not getting up to temp, then you are probably never reaching closed loop and that would explain you gas guzzling situation. Lastly, if the ETC is bad and it is telling the EEC that the motor is cool, then the pulse width will be calculated accordingly and the MPG will be down. This could also prevent the computor from reaching closed loop. But since your guage is reading low, I would look at the temp of the coolant as opposed to the signal that the ETC is sending to the EEC.
If I get it to run at normal temp, and replace possibly faulty coolant temp sensor, it hopefully would use less fuel? Maybe?
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From: The dark carnival
Originally Posted by monarokid
Thermostat is the correct one, but, the thermostat housing has a 1/2 inch spout that lets water bypass the thermostat and flow back to water pump. Would that be the reason it's running colder? There is also a fair bit of pressure in the radiator even when it's cold and spurts out when opening the radiator cap.
If I get it to run at normal temp, and replace possibly faulty coolant temp sensor, it hopefully would use less fuel? Maybe?
If I get it to run at normal temp, and replace possibly faulty coolant temp sensor, it hopefully would use less fuel? Maybe?
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