Hey guys, I'm a long time lurker and first time poster. First of all, I apologize for the long, long read, but I wanted to post as much information as possible so you folks would have a better idea of what's happening.

I have a 94 Formula that I bought in Oct '09 with 113k miles. Its ran very smooth, minus a fuel pump issue, (just rolled over 123k miles) until about a week ago when the engine started stuttering when I accelerate. I came here and searched for every thread with "stutter", "stumbling", and "hesitation", and basically found out that approximately 172 things can be wrong with my car, heh heh. I will list all the symptoms here and maybe someone with more wisdom than me can help narrow things down.

First, it only happens when the engine is warmed up and it happens worse the longer I drive. Example: I wake up to drive my girlfriend to work, 15 miles away. Car turns over quite a bit before it starts (which I believe is the fuel pressure regulator, or a leak in the line, as the fuel pump was replaced by the dealership in november) but it always starts. I can let it warm for two minutes and spin the tires out of the neighborhood, no problem. But as soon as the car reaches is normal operating temperature, I can no longer floor it from a stop because it stutters and bogs down. It feels like when my fuel pump was dying and I wasn't getting any gas, but I can hear the engine clicking. By the time I get to her job site, it starts stuttering even when I'm moving and need to accelerate. I need to floor it just to downshift and it still makes sounds and bogs down until I downshift to >2k or so rpms. I can accelerate either very slowly by staying in gear and <2k rpms, or I can floor it and force a downshift and a rise in rpms, thats it. Note that it takes ~20 minutes for this to happen and I can downshift and drive normally before then, I just can't floor it at a stop. Sorry if this confuses anyone.

Now, when I came here to look for my symptoms, 70-80% of the posts called out the plugs and wires as the #1 culprit. Me and dad spend 5 hours (heh, heh) changing all the plugs and the driver's side wires (we couldn't see a way to move or change the passenger side wires without removing most of the front of the car). That did not fix the problem, so I won't rule our that those last 4 wires are causing it. I read under a post somewhere that I can start the engine in the dark and see if they are arcing? Will that tell me if they are failing? Can someone go over that for me please.

Could it be my fuel pressure regulator/leak in the line that's causing this? I've had the hard starts for a few months now so I didn't think it would be connected to this since this only happened a week ago. Dad checked the pressure while he was driving it, but I'm pretty sure he drove it when it was cold and thus, it didn't act up and give him any abnormal readings. I'm going to hook up a gauge to it tonight or tomorrow and make it act up and see if thats a problem.

Several threads also point the finger of blame at the distributor. Short of just buying a new one and spending 5 hours to put it in there, which I don't really want to do (8$ an hour, awesome job), is there a way to see if the one I have now is failing? I live in Vegas, so it rains 4 times a year here, so I doubt its water fouled. But it might be the stock one, I'm not sure, and this is frustrating me and I want to take everything into consideration.

No, my engine isn't throwing any codes. I'm not sure what's up with my diagnostics system though, that may be borked to, because I got a 30$ code flasher from autozone and no codes flash at all for ne, not even 12, to tell me its working. so I don't know on that one.

Has anyone else had a situation like mine, or any ideas about what else could be wrong? This is really fustrating and I want to be able to drive my car like a normal person. Thanks for dealing with my story and I apppreciate any help that comes my way.

Two problems come to mind...1) the Optispark has died, and 2) the engine has an intake manifold seal vacuum leak. Try retorquing the intake manifold bolts to 34 ft lbs and see if that helps. If there is lots of oil leakage past the end seals and oil can be seen on the bolts, then it is a good bet that the manifold seals must be replaced.

Also, with an engine with this age, you should start thinking of doing a major tune up--that means ignition wires, spark plugs, Optispark (replace the water pump at the same time), new O2 sensors, MAF, MAP, TPS and its buddy the IAC along with the Vapor Canister Solenoid and the EGR Solenoid. You might also remove the EGR valve and check it out for smooth operation. It can break a seal and be a giant vacuum leak, but usually it only needs to be lubricated. Check and replace the fuel pressure regulator if needed. Look for 43.5 psi pressure when cranking the engine and ignition disconnected. Anything lower and it needs to be replaced.

Also, let's not forget the infamous rubber elbow going into the throttlebody. If it's been removed in the recent past, it might not have been intalled correctly. Usually, the underside gets doubled up and fails to seal on the throttlebody and that means a HUGE vacuum leak and the engine runs like crapola.

All of the plug wires can be problems, even if already replaced. Basically, in order to replace them properly, the exhaust manifolds must be removed. Then the wires can be routed correctly thru the looms. Otherwise, there is a risk of damage.

This is not an easy engine to work on, but once you do it, you will be an expert.

Good luck.

Check the fuel pressure before you start it for the first time. See if it has 42+ psi with the key on. If not,turn the key on/off a couple of times and see if it starts better. My car had a fuel line leak inside the tank that caused this. I dont know if the line that messes up comes with a new pump or not.

Try a new battery.

Me and dad took it for a spin today to try and further narrow down what the problem was, as he's never heard it before.

So we took it on the highway and at 65mph, I tried to give it some gas to downshift it into third, which it wouldn't do. I had to floor it to get it into second.

He thinks its my transmission now, not the engine, because of the way the car stutters and pings while trying to downshift. I didn't notice it before, but it would only stutter when trying to downshift.

It still stutters from a dig at a light though if I give it to much gas. And it still only does it when the car is warmed up. if it wa sthe transmission, would it still cause the stutter and ping while in first at a light?

Also, I didn't really play around with it too much, but I can manually downshift fine. Its only when the car wants to do it that I run into problems.

So, what do you experts agree on?

You may have stumbled on my topic about turning the lights off and looking for arcs. When my dad and I did that, we also sprayed soapy water on the lines, (very very fine mist) just to see if there were sparks. My wires lit up like a christmas tree. These LT1s run hot; they are supposed to. But with that heat comes dry rot. the stock wires can only take so much and if they are exposed for many years, they will crack and spark can escape. The thing that is confusing me is that the car isn't throwing codes. I think if it rains too hard my car's SES light will turn on haha. But that could be one of your issues. Your PCM.....

It probably won't solve any problems, but pull the negative terminal on the battery. It will reset the computer's long term memory and could erase an error it made in tuning.

Your dad said the transmission is the problem. Does the clicking and noise happen immediately or only after the car warms up?