Inconsistent misfire


May 11, 2024
Nashua NH
Vehicle Details
1996 Tbird 4.6
Country flag
Good evening guys. Hoping to get some help here. Had a cracked intake on my 1996 LX. Swapped it for a nos ford intake with the metal crossover. Everything went together great. However the car now has an inconsistent miss. When I first start the car it runs great. Idles good but as it warms up you can hear the occasional miss/ burp from the exhaust. Low rpm it's angry. As it revs up it gets a little happier. Same with driving it. Took it to work this morning as it needed gas and I work less than 2 miles away. By the time I got there it was misfiring pretty badly. But non consistant as in if i rap the gas fast it want to throw up all over itself and doesnt know what to do. However if I ease into it it seems to giggy up just fine. No check engine light. Just trying to figure out where to start. I appreciate any input.
Welcome. :)

Have you checked for vacuum leaks? Vacuum leaks tend to be worst at low throttle/RPM conditions.
I didn't notice anything however i can look again tomorrow. Unfortunately i cannot dig into it until the weekend. I did notice the ends on my FORD RACING plug wires that latch onto my coils are blown out and don't seat very well. I put 8 zip ties around the clasps making sure they stay on for the ride home but it didn't do any different. I appreciate your input and will be scoping it out tomorrow.
How old are the spark plugs? if they are old they could be bad or the gap might be off, I know its obvious but hey might as well check the easy stuff. Welcome to the forum, glad to have another member keeping these great cars alive
That's definitely a problem too; as I was thinking about my response the idea also occurred to me to have you check to be sure the plug boots were fully seated on the plugs.
Imho, any problem like that is usually spark plug wires, or water or coolant in the plug wells. plug wired die after about 3 years.

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