Here's a quick summary I just replaced my engine with a 383. The problem is it's hard to start I have to hold the throttle wide open to get it to start once it starts it dosent idle at all after a few minutes of fighting with it to idle it will idle on it's own. If I rev the engine up it feels like it has a really bad miss shakes the whole car. I took the car for a quick ride and it just shakes and runs bad. I checked the Spark plug wires made sure the wires to the fuel injectors are hooked up correctly.I have a mail order tune in it is it possible the tune is not right? I am stumped

 

check simple things first. Hard starting is usually related to fuel pressure so check your fuel pressure first. Also make sure that none of your plug wires are mixed up. Any codes being thrown?

 

No codes I Checked plug wires they all are correct but I will check them again. The car ran fine before I did the swap. The only thing I changed with the fuel system was the injectors.

 

Your first issues on startup and idle sound like typical tune issues that can be easily resolved.

As for your others, yeah, sounds like you are not firing correctly or on all cylinders.

 

I had the battery disconnected so I think it's just the computer relearning everything again.After about two minutes of running the idleing issue goes away. But that miss or whatever it is continues.

 

PM sent.

 

This may be a stupid question, but did you have the pcm re-programmed??

 

Yes sir I had the PCM reprogramed. I messed with car today and got the engine running good but the miss feeling I am getting is actually a vibration. It feels like something is not balanced properly I am thinking clutch not sure tho. As I rev the engine up the vibration gets worse. The clutch is a spec 3 and is pretty beat up. I couldn't afford a new clutch at the time of the engine swap. You all think the clutch could be the problem?

 

Was the crank neutrally balanced? If so then yes the clutch could be the issue as all replacement clutches are externally balanced like the factory ones. I would check on this ASAP.

 

I know the crank has been balanced. What does neutrally balanced mean?

 

Your flywheel isn't balanced. You probably left the weight on it depending what kind of flywheel you have. I'd take off the flywheel and get it checked. Wouldn't run the car anymore either as you'll damage the engine if you haven't done so already...mainly bearings.

GL...should be an easy fix. Been throught that same situation myself back in the day.

 

It's a spec flywheel. So exactly what do I do pull the flywheel off do I remove weights that are on it and take it to a machine shop and they will balance it. I did a search and seems people are just taking the weight off and reinstalling it.

 

I'm not positive on a manual flywheel but the autos flexplates actually have a weight welded onto or sometimes rivited onto it. When I had my 383 built theyneutral balanced it as wel land I had to grind off the counterweight from the flexplate.
Ask your engine builder if he balanced it with the flywheels offset balance in mind.

 

9 X's out of 10 you can just remove the weight and you'll be good to go.

 

I guess I will be pulling my tranny out again. This sucks I never knew that about the flywheels oh well. Thanks guy you all were very helpfull