'93 Formula "Sleeper"

[93formulalt1]

High rpm miss, I would check optispark, coil, fuel pressure. You know the opti was oil soaked so I would probably put my money on that but could be fuel too. Could be a ton of shit. Love the LT1. Bring it by when ya get a chance man. Glad you got it all sealed up.

I replaced the coil with a known good unit from the 93. I don't want to believe its the Optispark, so I'm going to ignore that for now. Lol. I'll repace the other spark plugs and check fuel pressure after I park it for the winter. Its really not that bad, just a minor annoyance when cruising at 60-65 in 6th gear, as it has a slight miss at low RPMs while under load. . . It'll get sorted out, just dont have the time, money, or inclination to try to figure it out now.

[93formulalt1]

I'm going to tackle a couple smaller projects today, including replacing the handbrake assembly with the one from the 93. The ratchet mechanism doesn't lock the lever in place when you pull it up, it will make the noise like its going to stay up, but as soon as you let go, it slips off the teeth and just drops back down. I'd feel more comfortable if it worked, since it isn't exactly impossible for the car to slip out of gear and start rolling.

Going to swap the plugs also, and I found another oil-soaked wire connection on the ICM harness, so I'm going to clean that out thoroughly with some electronics cleaner. Hopefully those items are contributing factors in the hesitation issue I mentioned.

Also, since swapping the coil yesterday, the intermittent issue I mentioned before that essentially left the car undriveable, hasn't occurred once. I believe that may have been the problem. I'm going to clean up the coil that I took off the 94, because it's an MSD Blaster coil, and if it's not shot, I'd like to reuse it. I think it was the ICM that was bad, honestly.

[98blackbeauty]

I would drive it a couple weeks before changing to that MSD coil. MSD's are known to be flacky.

[CJOFORM]

Don't change a bunch of shit at once. You won't be able to track down the problem that way. Just do one at a time. Like plum said leave the coil and icm shit you changed on there for a while.

So what exactly is it doing now? I thought it was a high rpm miss? Now it is low speed? Or am I reading this wrong?

[93formulalt1]

Don't change a bunch of shit at once. You won't be able to track down the problem that way. Just do one at a time. Like plum said leave the coil and icm shit you changed on there for a while.

So what exactly is it doing now? I thought it was a high rpm miss? Now it is low speed? Or am I reading this wrong?

Only misses at low RPMs while under load. IE driving in 6th gear at 65, RPMs are right around 1200-1400, and engine is under load. Theres a slight miss there, but I may just be hearing the exhaust leak, and it may just have no guts there. At high RPMs, it seems to lack power. Its very minor, but it's still noticeable.

[TylerT/AZ28]

if it was missing that bad to hear it, youd feel it when you drive.

[93formulalt1]

I think it's just the exhaust leak becoming more pronounced at those RPMs. It's livable for now. I'm not worried about it.

[CJOFORM]

Does it not build power up top? Like are you just shifting through gears wide open throttle and it falls on its face?

[93formulalt1]

Does it not build power up top? Like are you just shifting through gears wide open throttle and it falls on its face?

It doesn't fall on its face, just seems like it should have more power than it does.

[CJOFORM]

Ahh well youre already on the track for that, tune up, plugs and wires like you were planning on. See what happens. Good Luck.

[98blackbeauty]

Little miss and lacking power sounds like valves, maybe burnt or bad seals. Next step would be to do a compression check and leak down to see the status of the 150k engine.

[93formulalt1]

Little miss and lacking power sounds like valves, maybe burnt or bad seals. Next step would be to do a compression check and leak down to see the status of the 150k engine.

I was planning on doing that when I pull the motor/trans over the winter. Compression test, leak down test, and replace whatever I need to to make sure it lasts another 150k miles.

Im pleased to announce also, that it has been more than 24 hours since I finished the oil pan replacement, and the car has not leaked a drop of oil!

[93formulalt1]

Just scored a factory hurst short throw shifter for a decent price, can't wait until it gets here. The shifter is my only complaint about driving the car, nearly punching the dash shifting into 3rd is getting old. The stock shifter in my old Audi was better than the one in the 'bird.

Ordering the new clutch soon as well, that's one of many winter projects.