94mustang-swap

Hey so, i'm new to mustangs, and carbed systems. I recently picked up a 1983 ford mustang gt (loved it so much). I noticed the throttle was a bit sticky and ran a little rough on the drive back to its new home. Other than that it ran perfectly. After some investigation I came to the conclusion the carb was in general rough shape, so i picked up a QFT 600 cfm carb and swapped that on. after some headaches and tuning and fiddling with it I was forced to take it to a shop to take a look at my high idle problem and major vacuum line leaks. It ran great after that, then just a few days ago I did spark plugs on it and went to start it up again to check my work. It idles great and once i put it into first (manual) it continues to idle great but once I start giving it gas to start driving, it bogs down and stalls. I have to give it full gas to keep it running and it runs rough as hell when I do that. Its not misfiring so it must be another vacuum leak.... which I don't know how that would be caused by doing spark plugs ( i guess i knocked something). If anyone has any suggestions that would be great. I don't have resources to take it back to a shop as i'm just starting school again and I would like to learn from this.

89fiveeight

Generally you can hear a major vacuum leak. if you can't find it, spray a direct stream of wd40 on the lines until your engine spikes or drops off. That's your vacuum leak.

Mike T

Is this a new carb or one that's been sitting up?

94mustang-swap

I will try that wd-40 trick, thats a good idea. and its a brand new out of the box carb. thank you so far for the advice.

94mustang-swap

I also want to check the timing (not saying I don't trust the shops work, but seeing is believing) so does anyone know the timing setting for this 5.0? i cant seem to find it anywhere -.-

Mike T

13-14 degrees, if it pings at WOT, back it off and/or try 92 octane gas.

94mustang-swap

Alright I will try that all tomorrow hopefully, I will let you know what news I get from this. thank you again for the help.

94mustang-swap

I did a quick run through on the vacuum lines with the wd40 and I didn't find any leaks, (no bubbles, or change in engine speed and performance) so I closed the hood and tried driving it and the problem continues. I haven't been able to check timing yet due to canadian weather so on a warmer day I will do a more thorough walk through on the vacuum lines. But could a leaking intake manifold gasket cause, or at least contribute to some of these issues?