I'm running into a problem with my car where after I drive it for a while (25 minutes or more) that the car starts to backfire and starts to feel like It wants to stall if I go over 2500 rpms. As long as I do not go over 2500 rpm i can drive the car without problems. If the car is idling I can rev the car over 2500 rpms without a problem. I can even shift it into neutral while driving and rev the car without a problems. Please help any sugestion with be greatly appreachated.

I have a couple of guesses. How old are your plugs and wires?
How old is your Catalytic converter?
Are there any codes. All a person can do is guess if you dont check your codes. There are some threads on here that tell you how do do it with a paper clip. Go to search and do a search on checking codes. Is your Check Engine Light on?

The spark plugs and wires were just changed about 8 months ago. A new exhaust system (catacytic convertor and flowmaster muffler) put on May of last year. The check engine light is not on. I'll check the codes but the light has not come on. I've also had the IAC replaced, the alternator, starter, battery, battery cables, distributor, and a tune up done all in the last year. this problem only recently started and never have had any problem with the car. When I first start the car I can run it just fine and I can drive it for a while without a single problem but after about 25 minutes the problem starts. Thank for any of the help you can give.

fuel filter, or pump?

has the filter ever been changed?

Yes, The filter has been changed but I have not replaced the fuel pump.

Could it be the injectors? I too am having this problem did the same thing you did and the fuel pump on my car was changed a year ago w/ filter.any other advice would be great!

In my case the car runs fine for about 25 minutes. No misfire, good response, Can WOT and everything without a problem. Could the injector run fine for a while then mess up? I also notice that my temperature gauge goes up to about half way when the problem happens. I'm lost as to why this is happening now. I'm going to check the codes this evening I'll see what they say.

Knock on wood, my temp guage hasn't done that yet. let me know what you find out.

Have your ignition module inside the distributor tested. Most ignition failures occur when hot. Make sure when you bring them the module that they test it until it's hot. If it's cold, it may or may not pass the test, but I'm willing to bet it will fail when hot and it's only a matter of time before it fails completely, more than likely leaving you stranded somewhere.

Thanks, I had forgotten about the ignition module. I have had it for about 5 years, is that about the life of that part? Also is there a particular one I should get.

I did some testing. My fuel pressure is between 38 and 42 psi. I checked the code and all I got was the 12 code (flash, pause, flash, flash) repeatedly so there is no codes. I'm at a lose. I'll check the ignition module. Could a fuel pump be messing up like that? Works for awhile then stops. Although It stopped top when I went inside to eat and came out and drove home so the ignition module could be it. Off to go see thank for the direction.

I'LL be checking mine on sat. let you know how it went.

Case solved I think. Thank to Maverick H1L for the tip. Replaced the ignition module and no trouble yet. Thanks again to everyone.

Wasn't able to check out mine, had to cut down a tree that fell over in the yard. I'll change mine also. Thanks for the info.