Car: 94 5.0, 225,000 miles, 2 owners, rode hard and rode highway. Real work done on it...not yet.
Symptoms:
1. Check engine light.
2. high idle, 1200-1300
3. When it is at around 800, engine rocks badly. Sounds like it is dying out.
4. Low chirps, at intervals with the idle, at around 800., while engine is rocking.
5. Very bad low end pull. Worse than ever. Hard time accelerating under 2000.
So I am thinking that I am in trouble. Could it be the pistons? Gaskets?? Manifold???
So if anybody out there might know what is going on, me and my 5.0 please needs help!
Well, I would do all the basics so you have a fixed starting point. By basics I mean replace the spark plugs, rotor, distributor cap, new spark plug wires, fuel filter, oil change, lube and clean the MAF element. Once these are tended to your question will either be answered or it will give you a focal point to address a particular issue.
Clean your MAF Sensor. Should clear up 90% of your issues. Disconnect your Bat for one whole hour. durring that time clean our MAF, TB, ACT, and IAC. Then check back.
TB = Throttle body
MAF = Mass Air Flow(in stock air filter box or end of intake tube)
ACT = Air Charge Temperature(on intake tube)
IAC = Idle Air Control(on TB)
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1994 GT AODE, 3.55, shift kit, BBK H PIPE, K&N, XLerator Performence Mufflers (soon to be Super 44's), MSD(Cap, Rotor, TFI Blaster Coil), and 9mm Ford Racing Spark Plug Wires, Ford Racing B Springs.
check vacuum lines also that would cause your inconsistant idle and the rocking
also it wouldnt be a bad idea to get a pcv valve they can cause alotta problems too id recommend getting the motorcraft one from the dealer tho and not one from auto zone
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1990 lx 5.0
302, bbk cold air, ported heads, smog pump delete,thrush mufflers with x pipe, posi with 3.27 gears, aod with shift kit, bbk sub frame connectors, moroso drag springs
gotta love the notch!
2000 focus spi 5 speed, 35 mpg and runs like a champ
First thing to do is pull the plugs and look for signs. The plugs need to all look the same. If one is oil or looks like its not burning then check the compression on the motor. The motor needs fuel,spark and compression.
You need to find out what you are working with before you spend money.
After you confirm that each cylinder has compression. then check for spark at each cylinder. Make sure its is not only sparking but burning. compare all the old plugs. It could be an injector, vacuum leak at under the intake, maf is dirty. Or like my car with 202k miles on it the timing chain is so old that the timing jumps around?
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1988 coupe race car 2700lbs 366rwhp
1965 2+2 fast back 4 speed tri power
1968 gt/cs 347 5 speed
1970 mach 1 428scj 4 speed v code 410 rwhp stock
1990 gt drag car 780hp on motor
1994 gt, 1998 svt cobra
2003 svt cobra 456rwhp
The very first thing you need to do is take a trip to AutoZone. Go buy a code scanner for a Ford OBD1 computer. Just go to AutoZone and ask the guys for it. The OBD1 scanner is a MUST HAVE for anyone with a 1995 and before Ford.
2- When was the last time you gave it a tune up?
I give mine a tune up once a year, whether it NEEDS it or not. It's just good to stay on top of things.
And just like RCRacer said, after you do all those things disconnect the battery for about 30 minutes to an hour. That will reset your computer and turn your check engine light off. If the check engine light comes on after that then read your codes. You might also have a bad o2 sensor. But do those things I listed and then we'll move on from there.
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-1994 Mustang GT... K&N filter,GT40 tubular intake,BBK Full Length Headers,modified midpipe & Flowmaster muffs, timing at 12*. Best time- 14.74 @ 93.16 -Check profile for pics of our car collection! -Member of MBMCustoms Car Club - AmericanMuscle ROCKS!! - "Save a horse, drive a Mustang!"
1994 Mustang 5.0 needs help! 
