Here's what I'm working with-88 Formula with a/c and nothing else, LB9, 5 speed, 3.45 gear. The car is bone stock with 95K original miles, motor is tight and appears to be untouched. I've done all the normal tune up stuff-cap, rotor, plugs, wires, pcv valve, Delco O2 sensor, Mobile 1. Replaced all the rubber vacuum lines. I've adjusted the TPS, timing set at 8 degrees. I put a test pipe in place of the cat to rule that out and it has a Dynomax cat back on it. It has the correct L98 exhaust manifolds and y-pipe. I verified that it has the correct memcal in it-AKFX. It had an "048" ignition module in it that was date coded correct to be original so I replaced it with the correct "369" module-didn't make any difference. I did a complete brake job on all four corners so I'm confident the brakes aren't dragging any more.

I can't get it to run any better than 14.80's at 93 mph. I have tried various shift points and it seems to like 5000 rpm best. The tach is dead accurate-4300 rpm thru the traps. It seems to 1/8 mile better, 9.50's at 74 mph.

I have been fighting an intermittent code 54. I have replaced the fuel pump relay, maf relay, maf burnoff relay, and the oil pressure switch. The oil pressure switch was bad as the weatherpack connector was full of oil but I'm not sure if any of the relays were bad. Thought I had it fixed after the oil pressure switch but it has done it again since.

This is what I'm thinking the problems might be-

1- There is still a poor connection or ground somewhere in the fuel pump circuit and it's not getting full voltage/current.

2- The fuel pump is weak.

3- It doesn't have an L98 cam in it like it should

I'm determined to get the car running properly, at it's optimum before I modify anything so please don't tell me to do any upgrades or modifications now-I'll do that after I get the car up to the baseline it should run bone stock, and I think it should pull 96-97 mph without any modifications.

Is there anything I've missed?

 

Too much advance and too much fuel are just as bad as too little. Make for sure that nobody has messed with the fuel pressure regulator. You should see 43-46 PSI with the vacuum hose disconnected from the regulator. More or less and you need to be finding out why. I would reset your initial timing back to the stock 6*BTDC. Too much timing will cost you more power than the same amount too little due to knock retard. Speaking of knock retard, you should run a good top-end cleaner through the engine. I would Sea Foam it with a small vacuum line and T hooked to the passenger side vacuum fitting on the TB. It is a place that all cylinders can draw equally and it will clean the plenum, runners, LIM, head ports, intake valves, pistons, and chambers. You will be amazed at what can and will come out. Be sure to change your fuel filter. Your original injectors could also potentially be causing you issues. A flow matched set of the original size that have been cleaned and tested could definately be worth it. Like you said you could also have a L03 longblock. I have seen it before, even on a car with the ORIGINAL engine.

EDIT- I also forgot to mention that being a 1988 with only a single cat you only have 220 HP/290 TQ stock. You won't go as fast as the 89+ cars with 230/300TQ stock. Not a drastic difference but I would think its worth a tenth or two in the 1/4 and maybe a couple of mph.

If you really want to GO ditch the stock manifolds, Y-pipe, and open up the lower intake and plenum with some port work. Make sure you have the L98 cam, if you don't put a Production LT4 cam into it. You might also add a fresh set of valve springs and go for some 1.6:1 self-aligning roller rockers. You could get some low 14s and upper 13s with the above mods.

 

Appears to have the OE regulator, but I need to buy a gauge for FI to to test the pressure. I have been wanting to run some SeaFoam thru it but couldn't figure out where to put it in to get it to all the cylinders-Thanks! I did replace the fuel filter, and I checked the resistance on all the injectors-all were within .1 ohm and in the middle of the spec.

Could old temp sensors cause problems if they were sending inaccurate readings, or would that just cause it to throw codes? This thing runs a LOT better before it gets up to temp.