Car is a 95 T/A w/306 cam and all the trimmings (stock heads). I made a short blast and the car then started missing like a burned plug wire or something. I got it home (oil pressure was fine and so was temp, so I figured it would be alright). Changed all the plugs and wires and it didnt fix it. Things I am thinking are broken valve spring (I am using the comp dual coils), bent pushrod (although there is no noise), collapesed lifter (although again, no noise, so seems unlikely).

What else could cause this? Seems like the number 5 cyl is running alot cooler then the others bassed on my highly scientific spit on the headers method. The car starts up great, and other then the miss it runs fine as well with no noticable smoke or anything, just like one dead cyl.

Any suggestions?

 

When it idles, are you hearing a consistent miss?

 

with the cam it is hard to hear, but yes, I am sure it is.

 

Any black smoke or codes?

 

A consistent miss could be a broken valvespring I guess if you have changed the plugs and wires like you said. A more random misfire problem could indicate an opti going out.

 

nope, had a buddy drive behind me as we took it from my house to my buddies garage which is about 15mins and he said he couldnt see anything coming out the back. it misses hard enough that you can not cruise under 2k rpm's with out it getting some violent bucking going on. no codes either.

 

it is definitly constent, from the second it is started until i shut it off it is missing. will a broken spring be very obvious with the covers off? since they are dual coil could it be the inner coil?

 

It could be the inner one I suppose but with the outer one still intact, you should still idle ok and have good power until 5k or so when the valve starts to float. I would say it will be very obvious like a majorly loose rocker, broken stud, or something like that.

 

fixed it today, thanks alot. ended up being a fuel injector pigtail had come loose from the injector. i didnt use the clips when i put everything back together.

-james

 

Good job James! Now get back on the road and give those Mustangs some hell!