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I just bought a 94 Formula and noticed that the two bolts that hold the accessory bracket to the block as well as the one hiding below the alternator ear were missing. So the entire bracket was moving around. I was able to replace the second bolt in the head but I noticed the reason the two bolts that go into the block were missing is because the bolt holes do not line up. They seem to be off by about half the width of the bolt hole, I can see both holes through the bracket but they don’t align. I tried two DIFFERENT brackets, one off my 94 Z28 and have the same issue. I could get the bracket to bolt to those holes but then the ones in the head would be misaligned. Any suggestions as to why this would be happening? Are the heads on backwards?
my initial theory was that the car has an LT4 in it from the first owner (I’m the third) because it has some chop like a really mild cam. I figured since the accessories on the vette bolt to the drivers side of the block the fbody bracket would never fit correctly on the passenger side.
Have you tried loosening the other bolts for the accessory bracket to see if it will rotate enough to align all the holes?
I'm not aware of any external differences between the blocks used to build LT1’s and LT4’s. They are all the same casting number. Does the block have “327” (last 3 digits of the casting #) cast in the front of the block? If it was an L99 block (265ci “baby LT1” - 4.3 cast in side of block) it might have significant differences.
Have never seen anyone on this site with a similar problem in the 22 years I've been here helping LT1 owners.
[QUOTE=Injuneer;7011087]Have you tried loosening the other bolts for the accessory bracket to see if it will rotate enough to align all the holes?
I have, the only way the bottom holes in the block will align is if the holes in the head no longer align, but it is definitely a 5.7 and it definitely has stock aluminum heads, is it possible a thicker head gasket change in the past could have altered the position of the cylinder head? Or something of that nature? Should I be more concerned about the bolt holes in the block being attached to the bracket assuming I’ll only ever be able to get two of the 4 mounted?
Could be that the heads were milled far enough to throw off the alignment. If the bracket holes in the block line up and the ones for the head seem skewed away from the direction of the block deck, then that is likely the issue.
Could be that the heads were milled far enough to throw off the alignment. If the bracket holes in the block line up and the ones for the head seem skewed away from the direction of the block deck, then that is likely the issue.
Fastener #21 is missing from my install. Does anyone know this bolt size/thread pitch for the lower rear mounting arm? I also think I put the arm/bracket on upside down. Gonna pull it back off and inspect it today but wanted to pick up that bolt #21 I'm missing.
Could be that the heads were milled far enough to throw off the alignment. If the bracket holes in the block line up and the ones for the head seem skewed away from the direction of the block deck, then that is likely the issue.
Without taking it all apart again and using the power of my brain, they seem to be skewed in the opposite direction. As if the heads are thicker than factory. But if what you said is the case it’s more milling than I’ve ever heard of before, like a quarter inch.
Re-orienting myself to the picture of your bolt hole, it is obviously the hole going into the block that is normally hidden behind the plug wires (in the pic from my website added by Eric). So, in this instance, it looks like you have the bracket bolted to the head and trying to bolt it to the block. Your pic shows the bracket pushed more into the lower centerline of the block, leaving the block hole out of alignment to the left. That means to me that the head is sitting lower on the block deck, causing the skew. It seems you bought the car with this situation and maybe don't know the history of any head or block deck work that could shed light on the issue.
I would expect it would also cause a problem with intake manifold mating that would need attention, too.
Re-orienting myself to the picture of your bolt hole, it is obviously the hole going into the block that is normally hidden behind the plug wires (in the pic from my website added by Eric). So, in this instance, it looks like you have the bracket bolted to the head and trying to bolt it to the block. Your pic shows the bracket pushed more into the lower centerline of the block, leaving the block hole out of alignment to the left. That means to me that the head is sitting lower on the block deck, causing the skew. It seems you bought the car with this situation and maybe don't know the history of any head or block deck work that could shed light on the issue.
I would expect it would also cause a problem with intake manifold mating that would need attention, too.
after my previous post I thought about it more and I think you are right. The previous owner (I’m the third) didn’t even know the problem existed and can’t help me on it all. He just dumped it when it started running bad. What could be the reason the block was decked so much? The only info about its past I have is that at one point it was set up for nitrous and has a “nitrous fuel pump” with “double the pressure” and that’s it. the first owner pulled all the plumbing but left the pump apparently. I have a feeling a pcm tune for a wet kit in years long past are what’s causing the overly rich condition as it’s supposedly ran rich as all heck since the previous guy bought the car.
edit: the intake manifold doesn’t seem to have any mating problems. I’m assuming that was probably decked at the same time as the block.
Is the “nitrous fuel pump” an NOS brand, and mounted inline, on body, in front of the rear axle, flowing into the fuel filter? NOS sold a 5176 dry kit, with a pump like that. The nitrous line, when activated, applied a regulated pressure to the vacuum connection on the fuel pressure regulator. That boosted the fuel pressure close to 90 PSI, which supplied the extra fuel required for the nitrous directly through the injectors. Without the nitrous system operating the stock fuel pressure regulator had no problem maintaining the stock “no vacuum” 43.5 PSI fuel pressure. Did not cause the engine to run rich if installed correctly.The stock Multec injectors however did not operate well ar pressures that high, and needed to be replaced. Been there, done that.
Is the “nitrous fuel pump” an NOS brand, and mounted inline, on body, in front of the rear axle, flowing into the fuel filter? NOS sold a 5176 dry kit, with a pump like that. The nitrous line, when activated, applied a regulated pressure to the vacuum connection on the fuel pressure regulator. That boosted the fuel pressure close to 90 PSI, which supplied the extra fuel required for the nitrous directly through the injectors. Without the nitrous system operating the stock fuel pressure regulator had no problem maintaining the stock “no vacuum” 43.5 PSI fuel pressure. Did not cause the engine to run rich if installed correctly.The stock Multec injectors however did not operate well ar pressures that high, and needed to be replaced. Been there, done that.
Time to check the fuel pressure.
none of the above. If there is in fact a different fuel pump it’s mounted in the tank. They did the trap door mod so here’s an image of the top of the sending unit if that gives any information at all.
furthermore it has a stock FPR (isn’t leaking I checked) and stock rails but accel 23lb injectors. Pretty sure the previous owner went to 23s because he thought they would dump less fuel. Wrong I know but the guy did a whole lot of other stuff wrong too. Also when I prime the pump fuel pressure will jump but. When I let it sit for even a second the pressure drops back to zero. No fuel will come out of the shrader valve unless the pump is primed.
if this is a problem with the pcm or tune would I be able to pull the pcm out of my 94 z28 and swap it right in? If it runs fine after that point I’ve found my issue.
the only reason I’m thinking it’s not a sensor or ignition problem is because after it floods the crap out of the motor and I unplug the injectors it will RUN just fine for a few seconds until it uses up the fuel sitting in the cylinders.
It also has this on/off toggle switch and what I think is the GO button for the nos running into this black box under the dash. Don’t know how that could be related but it’s a little more info
