20 Most Recent 1999 Mercury Grand Marquis - Page 9 Questions & Answers

have to drop the gas tank

Both doors will not unlock with the key? sounds like the lock motors are jammed this is common on your model after years of service, try turning the key with as much force as you can without feeling it bend, this should overcome the frozen lock rod motors

The following are the general instructions on the start of diagnosing any electronically controlled engine or transmission problem.

The engine and the automatic transmission (transmission control is only for automatics, engine is still computer controlled no matter the transmission type) in this vehicle are computer controlled and in most cases when a fault occurs a fault code is stored in the memory of the computer control module. There are exception to this, such as the Mass Airflow Meter and fuel pressure problems. What must be done is to have all the basic testing done such as a scan of the system for fault codes as well as a check with a live data scanner tool for engine functions that are not within range of normal, a trained technician is required to know what is correct and what isn't, then based on careful diagnostics done from a factory repair manual the correct part is replaced or the wiring repaired or the computer replaced (known as the PCM or ECM,ECU), which is very rarely the problem. Other basic checks must be done as well such as mechanical problems with the engine as well as engine state of tune and mileage on the engine. The transmission can have mechanical issues as well such as no gear engagement at all or a failed pump or other pressure related problems. Also engine mechanical problems can and do cause many drive-ability related problem such as rough idle and other symptoms.

Rough Idle covers several symptoms. Do you mean Idle (RPM) goes up and down or do you mean it is too low and car tries to stall? Idle is dependent on fuel delivery and spark Depending on your mileage and driving style it is more likely an Idle Air Control valve, Mass Airflow Sensor or Throttle body. I would purchase CRC MAF Cleaner and CRC Throttle Body cleaner. you will need to disconnect the induction hose from the air filter and throttle body. On the Taurus/Sable the air filter is loated on driver side under hood. Trace back from it and mid way youwill find a plastic cylinder that is wired in with a plug. Unplug the MAF. Make sure and notate which side is facing the engine as the air flow has to be the right way. I put a dot on the side that should face inward to remember the flow direction. Find a ventilated area and take the CRC MAF cleaner and spray the inside of the Mass airflow from about an inch away. Be careful there are very fine wires inside that can be broken by the nozzle by touching or being too close when spraying. Spray liberally and then set aside to dry. Continuing up the intake you will find the throttle body whihc is a cirucular intake that is metalic It has a butterfly valve inside. Use the same CRC brand but this time us CRC Throttle body cleaner. DONT USE CARB CLEANER OR OTHER BRAND. Ford coats their Throttle bodies with teflon and any other brand can eat this lining away. Clean in short bursts. You can gently take a clean shop rag to wipe inside with your finger as sprayed to dislodge some of the dirt, but be gentle. Dont use stiff brushes.. A qtip, a soft bristle tooth brush with very light pressure. as well. Clean it very well. Place rag underneath to catch any run off. After its cleaned and teh MAF is cleaned, replace the air filter and reassemble the unit. The car will be hard to start at first. Turn it over a few times and it will start. It will sputter a bit and then should run better. Start with MAF and Throttle body first. then move to plugs..Finally, the MAF and Throttle body should be cleaned every other oil change.

It records the speed of your wheels rotation.(makes your speedometer work)

I am sorry but you have a failed automatic transmission. You will needit removed and rebuilt.

Usually a Major tune up due. Go to Autozone and test for any system codes first.Change Coil Packs (major problem) unplug your battery. Spark Plugs and spark plug wires. Change the add 1/2 bottle of Seafoam to gasoline. Or Chevron Tekron Injector cleaner $39.00 bottle is betterSafe for all Sensors. This is a major tune up not a band aide. Your car will run smooth as new. Fill your gas tank before adding. The Sea foam is better. Add this straight to your Intake while running. You should see a large amount of white smoke from the exhaust. spray and REV/Hold down the accelerator. This is an awesome Intake Cleaner which controls your acceleration.Sometimes this kills the spark plugs so use cheap walmart brandclean, then change again if after you clear the bottle, run the car for until there is no more smoke. If it is still running rough, I usually change the spark plugs again, and walah/PRESTO!. You have a factory clean system. This stuff is magic.

Problems like this is really hard to troubleshoot from a sentence but I'll give it my best shot. A mechanic will typically check all the cruise control related fuses.....then relays. After these steps, it can go on and on. There's a good chance it's the fuses though. Good Luck =)

buy a new gas cap and reset the light if that dont work check the fuel filler neck to see if it is rotted if so the replace it and that should take care of that problem

If the blower works but no cold air, a mechanic would check to see if the system is low on freon, then check for voltage at the low pressure switch and the ac clutch as needed.

that sounds like a wiring problem. or bad fuses.

the termostat have a flat side and point side .flat side go to inside of the engine .