I need to know why my 1986 Mustang GT has 85 mph on the dash and seriously does not go over 85. Well, it does, but the engine noise is terribly loud and the engine sounds like its whining. I'm thinking its the transmission. I guess its stock, 5 speed manual. Once I get near 2000 rpm, its time to switch because the engine sounds like its over reving. I spoke to someone about it and they said I may have a 'limiter' on the car because he knew someone who's parents put a 'limiter' on his mustang. If you know what the problem is and how to solve it, please reply. Is this common in 86 mustangs?
Posts: 3897
Joined: 3/31/2005 From: Indianapolis, IN Status: offline
Yeah, thats NOT normal. No help on what the problem may be, but that car was mean in its day. You should be able to rev the gears well over 4000, or close to 5000 if my memory serves me correctly. I had an 82 Capri RS and an 85 GT and both engines were pretty much identical - the 85 speedo was a joke because you could get there fast. If that engine is running right you be able to peg that hit about 135-140mph - not that its the smart thing to do:)
I bought a 140MPH speedo from Ford Motorsports when I had my '86 GT.... Well worth the $. It does sound like you have other problems - have 'em checked out quickly.
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Torch GT Vert, Black Top Previous: White 69 Coupe Grey 86 GT Also: Red F250 Diesel Black Kaw ZZR1200
There could be any number of problems. Remember, this is a fuel injected car not carbureted. There are sensors and such. Also, that year was recalled for the throttle position sensor and the catalytic converters as well as the fuel rails. I will post a more in-depth explanation when I get a chance. I e-mailed you a request to send me your e-mail address so we can discuss this further. -Robert
ok. so what is the difference between fuel injected, and carbeurated engines? I guess I really am a newbie... But would you mind explaining that to me? What is better? faster? what are the pros and cons?
Like anything else, start simple and work your way up. First of all, look at the throttle. Is it opening all the way? You would be surprised how many times the answer is "no". Assuming the engine is in good mechanical condition (i.e. no bent pushrods or wiped out timing chain), proceed as follows. Check the throttle. Then check the ignition for a carbon streaked cap, broken rotor or faulty ignition wires (arcing, which can be seen at night). Check the coil. Check the air filter. Check the compression. If it is low, decarbonizing may be in order. That engine used "low tension" piston rings to reduce drag. Does the car have a catalytic converter? If it is the original one, it was recalled by Ford for getting plugged up and reducing performance, also indicated by the engine getting hot. Also, the throttle position sensor was recalled because it allowed the engine to fluctuate in rpm at idle more than 200 rpm. Check with the dealer. With your VIN, he should have a record if the recall proceedures were done. Also, the fuel lines were recalled to have safety clips installed to prevent the remote possibility of the fuel lines separating. The fuel injection relies on sensors which could be at fault. These are the O2, MAP (manifold absolute pressure), throttle position sensor and engine temperature sensor. All of these sensors help the computer to determine things like fuel mixture and ignition timing. The fuel mixture is changed by varying the pulse width of the fuel injector. The longer the width, the more the fuel. When changing sensors, you will probably need to know the calibration code. It is located on the valve cover. If you can't find it, the dealer should be able to determine it by your VIN. If not, one of the more common codes is 621ARO. Also, check the fuel pressure and the condition of the injectors. A faulty fuel pressure regulator or even a badly clogged fuel filter or faulty pump could wreak havoc on the system. A bad injector will allow a cylinder or two to drag, supplying no power. Also, make sure the fuel tank is venting properly. The distributor is aligned with an index mark on the block and the distributor body. This was the position at the factory and supplies the base timing for the computer to work from. Remember, the computer is making the decisions on timing based on all of those sensors. If timing is suspect, check it. I see some people mention the figure 11 degrees. I wonder how this came about? I am the original owner of my '86 and have never had the need to touch the distributor. Make sure the index mark is aligned and check the timing from there. It should be fine. With all of the complications of electronically controlled engines, people tend to lose sight of the basics: spark, compression, fuel. My guess is it's somewhere in the fuel system. I say that because it is usually the most neglected of the systems. Good luck, and let me know what you find.
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'86 Mustang GT - 
RE: '86 Mustang GT - 
