I have an '02 Lincoln LS V8 3.9 and it has been a great car. It just hit 93,000 and runs great. The problem is this - when i drive the car enough to get it warmed up, let it sit between 1-3 hours, it starts really hard. Ill have to turn it over 2-3 times and just keep on it before it finally goes. I just had it tuned up and my mechanic and i thought that might have fixed it, but it did not. When its cold i never have a problem with it starting, it fires up incredibly quick. Any ideas?
One of the things that are sometimes overlooked is the coolant sensor. The coolant temperature is important for fuel delivery. When the engine is cold the Coolant Sensor sends a signal to the PCM (Powertrain Control Module) to deliver a rich mixture just like a choke on a carburetor on a car. When the engine is warm the sensor sends a signal that tells the PCM that it is warm, the PCM will send a signal for a lean mixture so it won't flood the engine out. If the coolant sensor is stuck in a cold state, it will send a rich mixture all the time. You will probably notice that the engine runs better when it is cold than warm.
Have the Mechanic put the scanner on the car cold and notice the temperature on the coolant sensor. Run the engine for a while then check the coolant sensor again. If the Coolant Sensor is the same as when you started then the sensor should be changed.
This is just the beginning of the diagnoses, if this is it, problem solved. If not get back to us and we will look into this matter further.
So...i brought it to my mechanic and this was not the problem. We were talking and trying to come up with other problems it might be. Since this car has 2 fuel pumps he was thinking that might be a potential reason. If it were the pumps, wouldn't it be doing it more or all the time for that matter? My mechanic hasn't been able to get it to act up (of course) when its in his possession, so hes really scratching his head on this one. Any other ideas? Thanks for the replies.
There is a Service Bulletin on the Idle Air Control (IAC) motor.
It is Service Bulletin number 03-7-3 or article number 03-3-5 dated 2-17-03. It states that the (IAC) can cause a no start or hard start condition and not set any check engine light.
Some vehicles, may exhibit drivability conditions.
These may include:
No start, Difficult to start Stall.
Hesitation/surge while accelerating or at steady speed
These conditions may be intermittent with no Diagnostic Trouble Codes (DTC) and no Malfunction Indicator Lamp (MIL). In some cases DTC and MIL may be evident.
Trouble cannot be identified with 95% of returned Idle Air Control (IAC) valves. The following procedure is supplemental information to normal diagnostics to facilitate accurate identification of malfunctioning valves. These symptoms would include engine stall, hard start, crank/no start, idling problems, and Idle Speed Control System related DTCs.
Also checking the throttle plate for heavy coking (Carbon build up) should be done. Clean throttle plate if required.
NOTE IT MAY NOT BE POSSIBLE TO DUPLICATE THE CUSTOMER CONCERN.
ALTHOUGH THE CONDITION MAY NOT BE DUPLICATED, IT IS RECOMMENDED THAT ANY EVALUATION OF THE IAC VALVE BE DONE IN ACCORDANCE WITH THE FOLLOWING SERVICE PROCEDURE STATED IN THE SERVICE BULETINS LISTED ABOVE.
Your Mechanic should be able to get this Service Bulletin, if not you can get a copy at ALLDATAdiy.com.
Also your mechanic should take a fuel pressure test not for pressure but for pressure leak down.
When you turn the engine off and wait the few hours the injectors (one or more) may leak and flood the engine. He may need to remove the fuel rail and pressurize the system and watch the injectors to see if they drip. If they do then the faulty injector (s) will need to be replaced.
These are a few more things to check.
Let us know how you make out.