Sputtering problem

[jjooohhnn]

I just bought an 89' GT. I do have decent knowledge of mustangs but I want to see who else has had this problem with their mustangs so I can dig right into fixing the problem. I have never had this problem before with my 90' GT and would probably waste time looking ino other things before finding the actual problem.

So... When I get to about 2500 or 3k RPM the engine acts like it's misfiring and sputters until I shift gears and go easy on it. The car came with longtube headers and the oxygen sensors might have been messed with or might even be original. After driving for a few minutes the check engine light will come on once it gets warm, about the time the oxygen sensors heat up to operating temp. I'll probably pull the code too see what it's doing but I'd still like to see what everyone else thinks. I was also thinking it might have a clogged fuel filter or the timing might be too retarded or advanced. I just got the car today and haven't messed with it yet but I'd like to get some ideas before I get started. The plugs and wires look new, same with the cap. Any ideas?

 

[srothfuss]

Start with the basics... Even though the plugs / wires look new, replace them. This will eliminate places to look. Don't forget the cap / rotor.


Maybe it's just got crappy plugs in it or you have a broken plug wire.


A cylinder balance test would be cool. I know you said you knew a lot about Mustangs. You can search for the words Codes and posts containing JRICHKER's replies on how to dump the codes. I am sure he will see this and hop in though.

 

[jjooohhnn]

You can search for the words Codes and posts containing JRICHKER's replies on how to dump the codes. I am sure he will see this and hop in though.

I hope so.

 

[srothfuss]

Here is one of his post's. It details how to get the codes out of the computer for free and only takes 5 minutes of your time.

http://forums.stangnet.com/showthread.php?t=606078&highlight=Codes

 

[jjooohhnn]

I swapped out the distributor with a known working dist. out of my 90' GT. Someone told me that a common problem with older fox bodies is that ignition module on the distributor will go bad causing the engine to act like it was for me. Well, the problem is gone after swapping out dists. so I'm fairly sure it was the ignition module that gave up. So, anyone who didn't mention the distributor (or ign. module) as a possible cause for my problem then they should definitley remember this thread.