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Discussion Starter #1 (Edited)
car: 1994 mercury cougar xr7 4.6 v-8
Scenario: Making a left turn at a "yield" green light with oncoming traffic.. what do you do when the time is right to turn??
smash the gas pedal right?


Well i've had to do this in my car, and when i Push the gas pedal in from a Dead stop to wot , the car Hesitates and stumbles (missfires).... I replaced the fuel pump a few weeks ago, i'm sure that's not the issue.
Also when i'm driving, i get the occasional "thump" of the engine misfiring. No codes no Check Engine light
car starts and idles fine.

coil packs?
wires?
plugs?

car only has 116k on it.... Replaced stock airbox with a tube (stock plastic air tube was cracked)

I haven't replaced any of those listed above since i purchased the car (about 4k miles ago)... i want to know what i should do to fix this issue. it's had 2 oil changes so far.

also, the Battery gauge goes WAY below normal with a/c, headlights running interior lights dim with blinkers, dash lights fluxuate ALOT.... i replaced the alt with a "reman" ebay unit but it's still the same....
 

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Check ALL the battery / ground cables / straps. Also the positive cables to the battery and alternator.

Get that battery load tested, or if it's over 2 years old, just replace it with a bigger one.

Being a 1994 V8, you do have the OBDII connector. Be worth picking up a scanner (I'm partial to a ELM type Bluetooth adapter and Torque Free or Paid on an Android phone, but there's a lot of other choices!) and datalogging it during such an event.

RwP
 

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you might need plug wires and spark plugs. How do your spark plug wells look right now? If you have vacuum leaks (which you likely do if you haven't replaced any lines), you'll get excessive fuel at higher engine loads, possibly enough to foul the spark plugs.

After you check your plugs and replace if necessary, if you still have misfires, you can scan the car to check the misfire counters to identify if there is a lazy cylinder. If two cylinders are showing more misfires than others, and if they are paired, that might identify a busted coil pack.
 

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Discussion Starter #4
changed plugs/wires... 2 of the old wires had broken tabs that hold them to the coil packs. Car runs like a beast now, no misses as of today. old plugs looked normal.
 

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changed plugs/wires... 2 of the old wires had broken tabs that hold them to the coil packs. Car runs like a beast now, no misses as of today. old plugs looked normal.
chop down your signature, or I will. K Thx. :)
 
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