Engine Need help figuring out misfire and backfire

[trystancounts]

So I have an 87 gt vert that I got this past weekend,fixed the firing order and everything,new plugs and reset the distributor. Now idle halfway decent but misses. It struggles on low rpm revs and low rpm driving but does decent at high throttle. It has an extreme fume from the exhaust and backfires when you let out of throttle after load. Been told it’s the fuel pressure regulator but it’s not squirting fuel out of it when I disconnect the vaccuum line,will it always do that when the regulator fails or no

 

[Mustang5L5]

Not always. Need to take a fuel pressure reading. Also check for vacuum leaks and dump codes in general as a starting point.

Would also be a sign of dropping a cylinder, or a stuck open injector. Really, there are a lot of potential causes so really need to start out with basic troubleshooting.

 

[trystancounts]

Not always. Need to take a fuel pressure reading. Also check for vacuum leaks and dump codes in general as a starting point.

Would also be a sign of dropping a cylinder, or a stuck open injector. Really, there are a lot of potential causes so really need to start out with basic troubleshooting.

It doesn’t smoke or anything so I don’t think I’ve dropped a cylinder,we’ve done compression tests and all,hard to check fuel pressure because my schrader valve is messed up

 

[trystancounts]

Not always. Need to take a fuel pressure reading. Also check for vacuum leaks and dump codes in general as a starting point.

Would also be a sign of dropping a cylinder, or a stuck open injector. Really, there are a lot of potential causes so really need to start out with basic troubleshooting.

I also found that at higher rom it runs like a scalded dog but anything below like 2500 rpm it hates

 

[General karthief]

Issues with old cars that have unknown mods and new owners. You don't know what they have done and/or if they are telling you the truth, in most cases they are passing off an issue they could not correct and have likely made it hard to correct, so you need to identify some things,
You say you corrected the firing order, please explain.

 

[trystancounts]

Issues with old cars that have unknown mods and new owners. You don't know what they have done and/or if they are telling you the truth, in most cases they are passing off an issue they could not correct and have likely made it hard to correct, so you need to identify some things,
You say you corrected the firing order, please explain.

They had the firing order wrong,plugs on the wrong diodes on the distributor

 

[General karthief]

Hummmmmm....
H.O. or non H.O.?

 

[nickyb]

I got a new Schrader valve from cj pony parts.

 

[Noobz347]

Fix the things that you know are wrong then move forward.