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Question: 2000 Ford Mustang mileage 71,000. Service Engine light on. Car runs rough between 35-40 Miles per hour. “Lopes.” Code reader says EGR Flow Low. Replaced EGR vacuum regulator and EGR valve with no luck. Lots of black smoke in exhaust when under hard acceleration. Service engine light used to be intermittent but now it's always on. Ford did warranty work on this car at about 20k miles, and removed the intake manifold, and removed "fouling" from the interior of the manifold. Any suggestions?

Answer: Your problem may be a failing mass air-flow sensor or possibly oxygen sensors. Try temporarily unplugging the primarily oxygen sensors and test drive the car. If your problem persists, the mass air-flow sensor probably needs to be replaced 

Question: 1967 Ford Mustang 289: I recently replaced the heater core. After flushing and refilling there seems to be a problem with the radiator running for an extended period of time. On two occasions after having driven from 1 to 1 1/2 miles, as I go to make a turn the car will sputter a little and then stall. It typically will not start again for 10 to 20 minutes. I have not had this problem in the past and I am at a loss. There seems to be no overheating when this happens although I have noticed a slight bubbling around the top spout of the radiator below the cap. I have been told this should not have anything to do with the problem but I am unsure.

Answer: One of two things is probably happening. Your carburetor could be flooding when you go into a turn causing the engine to die or you may have a radiator leak that is spraying coolant on the distributor shorting it out.

Question: 1984 Ford Mustang mileage: 1500. I have recently installed a modified 1967, 289 into my 84' GT. I had the block bored 40 over with Keith Black hypereutectic pistons. My cam is a Comp Magnum 270h, which puts out about .501 lifts w/ 270 duration. I have the 289 hi-po heads port matched and polished w/ a Weiand stealth intake. A Carter 625 runs the fuel. When I start the motor, the engine will jump to about 2500 rpm, and then if I try to kick it down, the motor stalls. It will also stall on its own if I let run. Initially, I assumed it to be either a carburetor problem, or a timing problem, but I have reached the end of my rope and patience. Everything has been checked two times over, including manifold leaks, fuel pump, fuel filter, cam lobe wear, compression, and timing, and still no results! The last time I had the car running, however, I did notice that four of my cylinders weren't fully firing until the rpms were kicked up (I gave it the old spit on the header test), and I was continually checking my plugs and the spark to each cylinder, and all were good! If you can solve this puzzle, or have any idea, you can have the car! (Not really but any help will be greatly appreciated!)

Answer: First check for a vacuum leak. If your engine is equipped with an EGR valve, be sure that it is closed when it is trying to idle. If there is no vacuum leak and the EGR valve checks out okay, check the carburetor. With the camshaft that you are running, the manifold vacuum will be low and possibly may be opening the power circuits in the carburetor. Check the idle circuit as only half the carburetor may be working at low speed. In addition, double check to make sure your valves are properly set - not too tight.

Question: 1996 Ford Mustang GT mileage: 85,000. I'm at the end of my rope with Ford dealers and my Mustang. Several times every week the car will not start. I'll try to get it to start, but it acts like its not getting fuel. I'll give it fuel, and it will start, then it continually stalls until I get about five miles (this is a guess since the odometer doesn't work either) down the road. I have to give it a constant supply of fuel until it works out its kinks and runs correctly. Several dealers have taken a shot at it. I've been told everything from getting new plug wires (mine are fine) to the IAC Motor needs replaced. One dealer replaced a sensor on the engine, but it started acting up again shortly thereafter. Can you help?

Answer: Your problem is likely the idle air control motor (IAC). Replacing it should fix your stalling.

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Question: 1998 Ford Mustang: I recently took my Mustang GT into a Ford service center for a slipping clutch. They told me that I have a self-adjusting clutch and that the clutch assembly needed to be replaced. After having it replaced, I have found that the clutch is a lot looser than before and as I drive, it is constantly changing from tight to loose to tight again. The clutch never did that before. I did a little research on this, and found that there should only be about an inch of play in the clutch. I have more than that. I talked to 3 different people at the Ford center, one of which was the service manager and they told me that it was working just fine and there was nothing else they could do for it. I took my car into a different service center for a second opinion. I was told that the master cylinder on my car controls both the clutch and the brakes. He told me that the master cylinder is leaking and needs to be replaced. I went back to the Ford service center and told them what I found. They said no, that the master cylinder does not do that and should not need to be replaced. Here's my question: Does the master cylinder control the clutch and brakes and if so, and it is leaking, by having it replaced would this fix my clutch problem? Is there anything else that would cause this 'slipping' of my clutch?

Answer: Your car is equipped with two master cylinders, the clutch master cylinder and the brake master cylinder. The clutch also has a slave cylinder that operates the clutch. It appears that either one or both of the master cylinders is faulty causing your problem.

Question: 1988 Ford Mustang : (mass air) won't idle properly... idles rough at 700 rpm, stalls out when you come to a stop from freeway speeds. Also sometimes when you crank it, it wont idle at all unless you hit the gas pedal for a few seconds. motor is brand new, injectors and fuel pressure checked out within spec.

Answer: We are assuming here that your engine has been modified probably with a non-stock cam shaft. If this is the case, what is probably happening with your car is the valve overlap with the non-stock cam shaft is allowing unburned fuel out the exhaust at idle. The oxygen sensor reads the rich mixture and the computer attempts to adjust the fuel to air ratio but it is beyond specifications. The computer will finally go to full lean which will cause your car to die.

Question: 1988 Ford Mustang  mileage: 150,000. I'm having a problem with the electric cooling fan. The fan will not come on which causes the car to run hot. The fan motor works when straight wired to the battery. It also works if I remove the wire from the electric fan switch and ground it. During troubleshooting I have replaced the electric fan switch, the a/c-cooling fan module and air temperature sensor. This is why I replaced the fan switch. Also note that the a/c compressor does not kick in, unless I jumper it at the accumulator press switch. When this is done the compressor kicks in and the electric fan kicks in, remove the jumper and compressor kicks out (like it should) and the fan runs for a few seconds (like it should) before cutting off. Also note the code scanner does not give any trouble codes. It all checks out fine. What have I missed? I have spent numerous hours troubleshooting and looking at wiring diagrams, with very small print, I'm stumped!

Answer: We would check for a faulty coolant sensor and trace the 12-volt power supply to the fan and relay.

Follow-up: I really appreciate the reply, but I figured out the problem. I knew the radiator cap was bad but I didn't think it was the problem until I replaced it. What was happening was the coolant was getting hot enough to boil out the cap but not hot enough to alert the sensor. I feel a little ignorant but that is what happens when you let the complex thoughts of a computer overrule the basic mechanical thoughts. It had been some time since I had worked on a vehicle but this will be a lasting memory. Again thanks for your reply!

Question: 1966 Ford Mustang mileage: 221,000. I was replacing the thermostat and put it back together with the housing and intake cleaned free of left over gasket with a air-powered tool and material to clean metal, put on the new gasket with The Right Stuff sealer and new thermostat, started to fill with water and it started leaking out of the passenger side of the housing. I took the housing off again, cleaned everything again, got a new gasket put everything back on and it leaked again. Took everything off again, cleaned it again, tried to make sure the metal was smooth on the housing and the intake, put it back together with the second gasket and more sealer, waited a few hours then filled with water and it leaked again from the same side. What to do now?

Answer: First thing to do is to make sure the thermostat housing gasket surface is flat. In addition, the mating surface on the intake manifold should be checked for flatness. If both parts check okay, glue the thermostat in place to prevent it from slipping down as you attempt to reassemble the thermostat housing.

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Question: 1996 Ford Mustang mileage: 50,500. My trunk is popping open by itself. I can hear it happen. It sounds like I hit the "trunk" button on my remote, but I didn't. It just started happening this morning, and has continued for hours now. I keep shutting it, but it keeps opening. After it has opened, I can still hear the "pop" noise continuing. Also, I can't open the passenger side window with the button on the passenger side. It will only open from the driver's side. Could there be a problem with a fuse?

Answer: Sounds like a comedy act. Scan the body control module and it will identify the problem you are having. There may be a short in the control module itself. It also could be as simple as a low battery in your remote controller.

Question: 1995 Ford Mustang GT  mileage: 68,000. My car acts very sluggish when it's cold or warm, like it hits about 2600 rpms and stops pulling. But, when the car is hot, it works fine. I'm also getting a check engine light reporting lean fuel mix. I've replaced fuel pump, filter, regulator, and 02 sensors, checked MAF, TPS, replaced everything to do with the ignition system, lots of other stuff to long to put here, but the problems continue. My fuel pressure is steady @ 32 and vacuum is steady at 15 hg (est. 4000 ft above sea level). Do you know what this could be?

Answer: The only thing left that we can think of is the coolant sensor.

Question:  1967 Ford Mustang mileage: 77000.  I have a question on how to tell the difference between an 8 and a 9 in rear end.  The tag is missing and the stamp on the differential is C70W 4025A 9.  The spaces represent a new line on the differential.  Any info would really be appreciated.

Answer:  The most sure fire way to verify the size is to disassemble the differential and measure the diameter of the ring gear.  Most Ford Mustangs with the 289 had 8” rear ends.  Most Mercury Cougars of about the same year had the 9” rear end.

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