backfiring
 

hey i have a question for anyone that can help.
so i have a 1993 ford mustang gt 5.0 H.O and it seems that everytime i start it up maybe after a min or two if i give her to much gas she backfires. also if i just run her at 20-25MPH for like 3 blocks it goes awya, but if im coastin' to a stop light and punch it, it also backfires, and its threw the exhaust. it just started and i need answers if anyone has any.

thankx,

Tony D.

Re: backfiring
 

The only time I've had that problem it was Fuel Pressure and Timing issues.

Re: backfiring
 

well i dont know a lot about the fuel pressure and the timing how could i check

Re: backfiring
 

I think we need more info...

1) Have you done any mods recently
2) Have you messed with the vacuum lines
3) When was your last tune up

If you don't have a timing light, or the means to rent/borrow/buy one, I'd suggest taking that car to a shop. Vacuum issues, fuel issues, distributor issues, timing issues? I'm recanting what I said cause I think it could be a number of things.

You need a Haynes or a Chilton's Manual for that car. It has a trouble shooting section. I'd start with a tune up and timing check personally just so I could eliminate simple things.

Re: backfiring
 

i just put a cold air intake on it, it hasnt ever had a tune up and i have never messed with the vacuum lines

Re: backfiring
 

ok don't get me wrong, but i had what seems like exact same problem, and please please i'm still a green horn to mustangs,i'd backfire when i got a little heavy foot, and when i'd try to maintain speed.....i thought welp lets check fuel filter.....etc. and after a new fuel pump and filter i still had problems...................and then i tried the one part i had just sitting around....a used distributor...it fixed it 100 percent better......i marked the rotor b4 i took the old one out and boom.........it fixed my problem,now dont kill me if u try it and it dont work for you. but thats my 2 cents =)

Re: backfiring
 

well thankx for your input, i have heard that the distrubutor could be the problem but i dint want to jump to any conclusions. idk im still going to run some checks on it to see if I find anything. only because im going to throw like $10,000 into the car during the summer time. so im just gunna use as little amount of $ as i can to fix the problem. but thank you once again.

Re: backfiring
 

Have you had the plug wires checked? Changed the plugs in my car a couple of weeks ago and it ran like crap. Would back fire & sputter but once I got moving at a decent speed as long as I didn't press down too hard on the gas everything was fine. I pulled the plug wires to change out the plugs with the ones I'd recently taken out and found out I had a bad wire. Changed out the wires and now it runs fine and the gas mileage is better. If you have a lot of miles on your car it wouldn't be a bad idea to change wires anyway.

Skip

Re: backfiring
 

You're running lean...you've likely increased the volume of air but haven't added fuel. The PCM is trying to, but can't add enough.
Best bet is to get a AFPR, and tune it with a wideband O2.
good luck...

Re: backfiring
 

try putting your old air intake back on if possible and see if it still backfires, if so i think its time for a tuneup or at least throw on some new wires first. :)

Re: backfiring
 

what is a wideband O2? and what does it do? i kinda had a feeling that i was running lean but i didnt know how or what would fix it. so im still kinda stuck here trying to figure this stuff out.

Re: backfiring
 

so it could be because i have a cold air intake on it