View Full Version : spark issues.....

12-21-2005, 11:52 PM
Can I be blowing out the spark on the 94? Seems as long as I keep the boost 12/13 psi or under, no matter what gear/rpm range, the car runs/accelerates fine, but once I start to push the gauge into the that range I get the dreaded bucking. I havn't had the chance to pull the plugs, but can there be anything else beside plugs or wires that would cause this? I would think fuel would be at any point in the high RPM range instead of boost related. Man at one time these cars were fun to own. Wish those days were still here.....:rolleyes:

Mike Puckett
12-22-2005, 05:49 PM
Tim, the only thing I can think of is a loose connection in the IC tubing somewhere. Ususally though, when I have a loose connection I can't get more than about 2-3 psi of boost before it starts to misfire. It can be blowing out the spark. The iridium plugs are supposed to prevent spark blow out. 12-13 psi is about all you want to run anyway.

12-22-2005, 07:40 PM
I'm going to change the plugs to see if that helps. It will bury the needle to 15+ psi with this cold weather and that 89-93 pulley on the SC, and that's with the headers and dual 2.5" to 3" to dual 2.5" exhaust.

Mike Puckett
12-22-2005, 08:57 PM
Wow, on my 35th now with the 95 blower, 70mm TB, and double IC with the same pulley I'm getting only 12. It's got a flowmaster exhaust which isn't as big as yours.

12-22-2005, 09:26 PM

I wonder if your D I/C helps in making your boost lower? This is what the 94 has, K&N panel, stock intake tube, 76MM MAF, stock TB, ported intake plenum, then the 3/4 top, the 89-93 blower pulley, stock I/C and out the stock heads with the shorty headers, cats and the rest of the exhaust.

After I get this miss/bucking figured out, next is the clutch/tranny. Feels as if the clutch is not disengaging at times when you push the pedal in. It's really really tight in the gear that you are in and if you get it out, it's next to impossible to get into another gear. Happens mostly when you are at a stop and seems to be worse after a good long drive. I'm guessing slave cylinder, but there's no fluid leak, and I replaced it when I had Rick do the motor about 12K miles ago.

Mike Puckett
12-23-2005, 12:20 AM
The can't get it in gear syndrome is notorious with SC's. The clutch drags and causes a windmilling effect inside the tranny making it difficult to put in gear. Supposedly machining the flywheel during clutch replacements is part of the problem due to the pressure plate being further from the slave cyl. I have Otis grease the hell out of the pilot bearing when he has the tranny out and along with a master and slave cylinder replacement mine stopped doing that and I've had no problems in years. I've got a NOS flywheel that I won't use if I go to an aluminum one. I haven't decided yet either whether to get another Centerforce, a Spec, or my NOS stock clutch/pp unit that goes with the flywheel. The double I/C does drop boost a bit. More than 15 lbs of boost can be dangerous to head gaskets. I have a 3/4 top on mine too but still have the stock exhaust manifolds. I have a friend from the track who has a set of the 96 headers on an LX TBird who is supposed to swap me even for my stock manifolds.

12-23-2005, 08:37 AM
After I get the heater core fixed in the Mustang I purchased so I can drive it and put the bird in the garage, I'm going to did deeper into the clutch problem. I'm going to replace the master cylinder for sure, I just hate taking that tranny out again, after about 6 times in the last year or so it seems for various things, to do the slave again.

Mike Puckett
12-23-2005, 10:01 AM
When my slave went bad it started leaking pretty bad. The red brake light would come on and I'd have to add brake fluid to the reservoir. The pedal would start grabbing close to the floor when the light was on. The fluid would drip of the bell housing and I had to put a dydi on it for the race track. Are you dripping any fluid? If that front tranny seal is leaking, at least you'll be able to fix that.

12-23-2005, 04:33 PM
When we put in back in the last time, just a couple weeks ago, from chaning out the clutch it was not leaking. Had to change the clutch because of a it having a chattering issue that had never gone away. Took the spec II out and put in the used centerforce out of that 89 that I had for a parts car. The spec had a spot on the flywheel and pressure place where it had glazed over for some reason. I took both to a driveline shop to have turned/checked out and both were in spec, so I can only assume the disc is bad. They said I could bring it by and the could check it out as well, just haven't had the time.

Mike I also have given out bad info. The blower pulley is a 5% not the 3% 89-93 style. I don't know why I was thinking it was the 89-93 one. Maybe I need to step down anyway.

12-28-2005, 06:09 PM
With my new exhaust, I have a problem hitting 12 lbs even letting 3rd wind up.

Mike, let me know when you go clutch shopping, I need one too. Maybe we can get a discount on buying them together.

12-28-2005, 06:58 PM
When Rick did my rebuild back summer of '04. I put in a spec stage 2 and was never impressed with it at all. I don't know if I did something during the install, but it never 'broke in' and would all ways chatter on 1st gear take off and any gear downshift when letting out on the clutch. I pulled it couple weeks ago and had the flywheel, and pressure plate checked out and both were in spec, so I can only assume that the disc is not. I put in the used Centerforce out of the 89 parts car I had. Don't know the milage it had, but I like it 100% more. The chatter was gone, and the pedel pressue was more like normal, unlike the spec and still seems to hold as good for my current set up.

For the stock LUK kit, it seems most on here recommend it for stock or near stock SC to around 250ish rwhp. Just an fYi...

Mike Puckett
12-31-2005, 01:23 AM
I'm hoping I can go another year before I change the clutch. I thinking of the Spec aluminum flywheel and another Centerforce dual friction clutch. This one has served me well. If it goes out unexpectedly during the season I've got an NOS clutch/pp/flywheel to get me by.