Fuel pump relay?

I'm glad you got it fixed. Let us know if you have questions in the future.

Thanks for using 2carpros. Com.
Joe

A bad EGR valve, if stuck open would make it idle rough. To check it, with the engine running, disconnect the vacuum hose from the EGR valve. Plug the hose and attach a hand operated vacuum pump to the valve. Apply 5-10 inches of vacuum. The engine should run rough or even stall. If it doesn't, or if it changes very little, replace the egr valve. Also inspect the vacuum hose for cracks or leaks before testing the valve.

You could check the fuel pressure regulator. It has 2 fuel lines going to it and a vacuum hose on top. Attach a fuel pressure gauge to the schrader valve. With the engine running, detach the vacuum hose from the regulator. The pressure should rise 8-12 psi. If not the regulator is bad. Also, if fuel is squirting out the regulator when you take the vacuum hose off, it's bad.

Check the mass air flow sensor. Very gently tap it while engine is idling. If idle changes, sensor is bad. I'm not sure which type of sensor you have, but you might want to take it out and see if the resistors are dirty. You'll see 2 of them in the mouth of the sensor unit. If they look dirty, you can spray them with throttle cleaner. Be careful doing this, they are fragile. Do not touch them with anything, just spray them. If that doesn't help, I'd check the O2 sensors next.

Let's back up first to where you said you changed the cap and rotor and the plugs and wires are next. You should change them anyway if they are due. You could pull the plugs and check them, see if they're carboned up or fouled. You could buy a spark gap tester, they' re cheap, and check for spark at the end of each wire. Or, like I said, if they're due for a change anyway, change the plugs and wires. When is the last time they were changed? Let me know what you want to do, or we could test the ignition coil also, before changing the plugs and wires.

Not sure on yours, but I know on earlier Taurus models, when the tps was replaced, it had to be checked with a voltmeter to be sure it was initially installed correctly, certain readings with throttle shut and open, on yours try loosening the screws slightly while the car is idling, rotate the entire unit either way if possible, see if the idle smooths out. Good luck. If the sensor is way out of range, check light should be on, but it could be out of whack a touch and still be within pcm operating parameters and not set the light.

I found another thing to check with the EGR system, the PFE, an electronic solenoid that gives feedback to the computer. It regulates idle and fuel air ratio in accordance with signals from the computer. It's also wired in with the TPS. It may explain the codes you got for the TPS and EGR system. I'm not sure if it's the same on the 3.0 engine but on the 3.8 it's a small gray box with a 3 wire plug and a tube going to the EGR valve. To check with a voltmeter, ground the negative lead from the voltmeter. Backprobe with a paper clip into the brown/lt. Green wire. If you can't get a paperclip in, you have to pierce the wire with the voltmeter probe. Turn the key on, engine off and the voltmeter should read 3.25 volts dc, + or -.25 volts. You could check it further by applying pressure with a clean radiator pressure tester and a hand operated vacuum pump. There are different voltage readings for different pressure and vacuum readings. Let me know if you want to proceed with it. Also if you pierce the wire, put a drop of super glue on it to seal it back up.

This is the first step, I will follow up later with testing the wiring harness, coil primary voltage and coil supply voltage.

Follow the coil wire from the center terminal on the distributor cap to the end at the ignition coil. Make sure the transaxle is in Park (AT) or Neutral (MT) and that the ignition is turned OFF.

Separate the wiring harness connector from the ignition module at the distributor. Inspect for dirt, corrosion and damage. Reconnect the harness if no problems are found.

Push the connector tabs together to separate.

Attach a 12 volt DC test light between the coil Tach terminal and an engine ground, then crank the engine. If the light flashes or is continuous:

Turn the ignition switch OFF.

Disengage the ignition coil connector on top of the coil and inspect for dirt, corrosion and/or damage.

Using an ohmmeter, measure the ignition coil primary resistance from the positive (+) to the negative (-) terminal of the ignition coil.

The ohmmeter reading should be 0.3-1.0 ohms. If the reading is less than 0.3 ohms or greater than 1.0 ohms, the ignition coil should be replaced.

Using an ohmmeter, measure the coil secondary resistance; connect it to the negative (-) terminal and the high voltage terminal.

The resistance should be 6,500-11,500 ohms with the ohmmeter set on ohms x 1000. If the reading is less than 6,500 ohms or greater than 11,500 ohms, replace the ignition coil.

The coil primary is the small 2 wire connector and the secondary is the coil output to the distributor. To measure the secondary, measure from the primary negative to the coil output.