katz_2003

iTrader: (5)

Mods in Signature. Ok here is the deal. The car has a horrible miss to it which starts around 5-5500 RPM and pretty much does it all the way up until you let off, it kinda acts like a real bad stutter like rev limiter but it keeps climbing (slowly) Runs perfect up until it hits the wall of misses. Here is everything I've changed/tested:

Brand New Plug Wires (Not arching)
Brand New Plugs
Brand new MSD Billet Opti
Brand new MSD Coil (old one was also msd)
Added a extra grounds (from head to chassis, etc.)
Fuel pressure doesn't drop when missing at high rpm (while driving)

I am lost...any help would be greatly appreciated!
I have a datamaster file but for some reason it wont upload.
I also will upload a video to youtube of a short 2nd gear pull showing the misses.

katz_2003

iTrader: (5)

Bloo Magoo

What did you gap your spark plugs at. Lower the gap because you have a high compression and you could be getting spark blowout.

katz_2003

iTrader: (5)

I would think I should have plenty of spark and not blowing them out. I'm only at 11.3 compression and my gap is .040.

96capricemgr

iTrader: (1)

Not arcing at idle means nothing about if it arcs under load and some new wires like I believe MSD are prone to that even when fairly new. The MSD opti and coil are more likely to cause you problems than they are to resolve anything.

.040 is plenty tight on gap. What plugs?

katz_2003

iTrader: (5)

I had TR6s in before with the miss then switched to autolite 104's just yesterday to see if that'd help. I had MSD 8.5 wires on before (didn't arc at idle) then switched to Accel 300+ prolly a week ago (no light show with these either) the miss didn't get better or worse after changing plugs or wires. Before the Brand new MSD I had a ACDelco Opti, I'm assuming its still good because miss didn't get better with new MSD Pro Billet either...

96capricemgr

iTrader: (1)

Do you have a spare ignition module you can try?
Have you inspected the springs and maybe checked pressures?

SS RRR

iTrader: (2)

How many miles on the springs?

94blackz

^^^^^^^^^^ this

katz_2003

iTrader: (5)

I haven't tried a new icm yet. I figured those things either worked or they didn't. I have not popped the valve covers yet to inspect the springs. It just felt like a spark related problem since I ruled out the fuel pressure. The springs have about 4000 miles on them. The car has never seen the track but I have done my fair share of street races. Most of those are highway/cruise miles.

katz_2003

iTrader: (5)

Well, I took the valve covers off and started checking spring pressures with them on (ones that I could get to) and all seemed good. None broken or cracked or anything so I started looking else where. I pulled off the coil plug ins and unwrapped the wires all the way back. There was a nick in one of the wires and the end of the wire looked a little bad so I ended up soldiering new ends on, plugged them in and went and tried it. Didn't hiccup, didn't stutter or anything! Pulled right on up to 6800 like its supposed to! Just wanted to post my findings because a lot of posts I find don't end up posting what was actually wrong.
So, if your car starts missing and you cant figure out why check the wires that plug into the coil! That was my problem and cured my miss 100%! Thanks for all the replies guys!

bufmatmuslepants

iTrader: (3)

Thanks for posting a followup, glad you found the problem.

nitrous2fast

iTrader: (2)

wow, that is an interesting solution to a problem.

katz_2003

iTrader: (5)

Just going to let everyone know that the problem in the video came back very shortly after I thought I had it fixed. I replaced both pig tails that go to the coil and it had fixed the problem for a short while. I think I now found and fixed the problem for good. I believe it was my ICM pigtail the entire time, I must have jiggled it around while messing with the coil wires enough for it to work. After ordering a new ICM pigtail and soldiering it on, the problem is now fixed again and I believe this to be the problem the whole time. Maybe this can help someone in the future...I guess nearly 20 years of wiring is taking its toll on the girl.