Hey everybody, i need some help solving my problem with my pony. I have a 98 mustang gt 4.6l engine is stock. the engine hesitates and bucks and will completely loose all power when under load, or heavy acceleration (merging on highway, going up hills). after the engine is at operating temperature, and wont let me go over 4000rpm before the engine cuts out completely. the weird thing is once the engine begins to loose power and hesitate if i shut off the engine and restart it it will have its power back for about 20 mins before it starts to hesitate again. its been hesitating for about 6 month now, and within the past week i got a check engine light with a code p1443 Evap purge valve fault. im wondering if it has to do with the computer cause when i restart the engine it runs fine for a short time...any ideas would be greatly appreciated i need to get this bad boy fixed...
98 Mustang GT Engine Hesitation Problem
- Thread starter bevanoff
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I don't know but I found this on another board. Hope it helps...
Ford On Board Diagnostics II, (OBD II) code P1443 means that the evaporative emissions charcoal canister purge sensor did not detect any flow when the canister should have been purging into the engine intake system. The purging, controlled by the computer,takes place when certain conditions are met, such as engine speed and temperature.What the computer operates to effect this purging is a 12 volt solenoid valve, solenoid means it has a moving piston in it which covers/uncovers ports in the valve so that flow does/does not take place. The "gunk" coming out of the charcoal canister will sometimes cause this piston to stick, resulting in purging not taking place when it should, the sensor in the purge hose detects this and sets a fault/trouble code and also turns on the "Check Engine" light. The electrical windings in these valves seldom fail, but anything is possible. To locate and check this valve, first find the charcoal canister, it will be a round or rectangular black plastic "box" with several different size hoses attached to it. If in doubt that you've found it, look at the bottom, there will be a plastic foam filter there---make sure it is not plugged up---. Once you've located the canister, start following the hoses attached to it. One will go towards the engine, follow that one along until you find the control valve that it attaches to, that's the valve that's not operating. Several things you can do now, just buy a new one and hope it is not the wiring or computer that's at fault. If you want to check it and the wiring, first, with key off, disconnect the two wire connector from it. Use a 12 volt test lamp, turn the key to "run" and check for current at both wires in the connector, one sould have current. Next, connect the test lamp between the two wires in the connector, start the engine and let it warm up, then run the engine up to around 1500 RPM or so, the test light should come on, if it doesn't, then it is the wire that was "cold" when you checked for power at the connector. or the computer. If the light comes on, then it is the valve. Remove it from the vehicle and clean it with an aerosol can of carburetor cleaner,use the "straw" that comes with the can and spray the cleaner into both hose nipples on the valve, alternatly spraying and shaking the valve. When you no longer get brown "gunk" coming out of the valve, reinstall it in the vehicle, but leave, if possible, the hose from the cannister disconnected. Start the car and let it warm up, (if need be), now raise the RPMs to 1500 or so. valve should now open and a vacuum should be present at the open nipple. If so, the problem is cured. On some OBD II equipped vehicles, repairing some problems will cause the computer to turn off the check engine light if the fault is no longer detected, other vehicles require that the computer be interfaced with and the code purged with a scan tool. Any questions, don't hesitate to ask. I'm curious as to what "Inspection Station" would not have sophisticated enough instrumentation to analyze the cause of a P1443 fault code.
Ford On Board Diagnostics II, (OBD II) code P1443 means that the evaporative emissions charcoal canister purge sensor did not detect any flow when the canister should have been purging into the engine intake system. The purging, controlled by the computer,takes place when certain conditions are met, such as engine speed and temperature.What the computer operates to effect this purging is a 12 volt solenoid valve, solenoid means it has a moving piston in it which covers/uncovers ports in the valve so that flow does/does not take place. The "gunk" coming out of the charcoal canister will sometimes cause this piston to stick, resulting in purging not taking place when it should, the sensor in the purge hose detects this and sets a fault/trouble code and also turns on the "Check Engine" light. The electrical windings in these valves seldom fail, but anything is possible. To locate and check this valve, first find the charcoal canister, it will be a round or rectangular black plastic "box" with several different size hoses attached to it. If in doubt that you've found it, look at the bottom, there will be a plastic foam filter there---make sure it is not plugged up---. Once you've located the canister, start following the hoses attached to it. One will go towards the engine, follow that one along until you find the control valve that it attaches to, that's the valve that's not operating. Several things you can do now, just buy a new one and hope it is not the wiring or computer that's at fault. If you want to check it and the wiring, first, with key off, disconnect the two wire connector from it. Use a 12 volt test lamp, turn the key to "run" and check for current at both wires in the connector, one sould have current. Next, connect the test lamp between the two wires in the connector, start the engine and let it warm up, then run the engine up to around 1500 RPM or so, the test light should come on, if it doesn't, then it is the wire that was "cold" when you checked for power at the connector. or the computer. If the light comes on, then it is the valve. Remove it from the vehicle and clean it with an aerosol can of carburetor cleaner,use the "straw" that comes with the can and spray the cleaner into both hose nipples on the valve, alternatly spraying and shaking the valve. When you no longer get brown "gunk" coming out of the valve, reinstall it in the vehicle, but leave, if possible, the hose from the cannister disconnected. Start the car and let it warm up, (if need be), now raise the RPMs to 1500 or so. valve should now open and a vacuum should be present at the open nipple. If so, the problem is cured. On some OBD II equipped vehicles, repairing some problems will cause the computer to turn off the check engine light if the fault is no longer detected, other vehicles require that the computer be interfaced with and the code purged with a scan tool. Any questions, don't hesitate to ask. I'm curious as to what "Inspection Station" would not have sophisticated enough instrumentation to analyze the cause of a P1443 fault code.
I have the same very common P1443 code on my 97 GT and it has caused no drivablity problems. It is strictly related to the emissions system, specifically the carbon canister purge and I can't see how it could cause such a huge problem at WOT. My CEL has been on and off for the last 2 years with this code and absolutely no drivablity problems.
My best guess is a bad fuel pump. I say that because it sounds to me like the engine is going very lean at higher loads. The old fuel pump probably just isn't able to keep up with the demand. As for why it is better after letting the car sit for 20min... because it gives the pump a chance to cool down. To confirm if it is the fuel pump or a fuel related problem, put a gauge on the fuel rail. At WOT, it should read a steady 39-40psi. If it drops below that at higher rpm, you found the problem.
My best guess is a bad fuel pump. I say that because it sounds to me like the engine is going very lean at higher loads. The old fuel pump probably just isn't able to keep up with the demand. As for why it is better after letting the car sit for 20min... because it gives the pump a chance to cool down. To confirm if it is the fuel pump or a fuel related problem, put a gauge on the fuel rail. At WOT, it should read a steady 39-40psi. If it drops below that at higher rpm, you found the problem.
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