bad misfiring in 5.0

i would check to ensure you have good spark through each plug wire (several ways to do it - your choice).
if you are good on the spark side, i would use a noid light or run a cylinder balance test to see if the injectors are firing correctly.

go from there. give the simple stuff a good once over (make sure all the plug wires are pushed on tight and all that).

good luck.

HISSIN50 said:

i would use a noid light or run a cylinder balance test to see if the injectors are firing correctly.

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Just curious what you do for a cylinder balance test?

p.s. I would replace your fuel filter, its a 9 dollar filter and only takes 20 mins to swap if you do it right. If that is gummed up like it was in my car, your mustang will backfire like crazy, sounds kind of like what you are dealing with.

DRblack50stang said:

Just curious what you do for a cylinder balance test?

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it is part of the self diagnostics; it is a test one can run while pulling codes. internet links, repair manuals and code reader instruction books should have a write-up on doing this test.
it is a neat little test. the injectors will be fired and assessed. if one or more does not pass, it will re-test up to two more times using modified criteria to see if the injectors fall within specs.

On that note, if i think my injectors may be gummed and want to pull them how tough is it?

fairly easy to do the injectors, just take the 4 bolts off your stock intake and it should come off. Then theres 2 bolts that bolt the fuel line to the lower intake on each side, take that off and the fuel lines should come up and your injectors will follow, make sure you take the O-rings out because they get stuck in the fuel rail.

The cam in the speed density motors was slightly more agressive, but won't have any effect on the way the engine runs with mass air. You need to get your 02's hooked up, or you will be constantly running in open loop, making the car seem like it's down on power.
Aside from that, like hissin50 said, check to be sure you have good spark; particularly on the fouled cylinder. Take a look at your cap and rotor and make sure they're in decent shape. Someone suggested replacing the fuel filter; I'd definitely go ahead and do that, seeing as how it should probably be done anyway. Lots of things you can do/check before pulling out your injectors on a whim.
Do you have access to a code scanner?

you can get kits for the injector - new o-rings and pintle caps. what do you plan to do once you have the injectors out? i hope cleaning them by hand is not what you are thinking. i might try a fuel cleaner that is self standing (car does not run while using it) and go from there.

good luck.

Oh well i really jacked this thread for which Im sorry, but I know a guy who clean injectors, im not sure how because I dont know how they work exactly, but apparantly he has a device to measure the amounts each is "injecting" and then if they were all different or way off he knows they are bad and I guess uses like a supersonic cleaner maybe or I could be way off. A guy I know had his done in his pickup and they were all different amounts and when cleaned he said it made a work of difference. My car sat for 8 years before I bought it and then the rust in the tank gummed the fuel filter making it backfire like i said earlier. Well i went through 4 fuel filters in 2 weeks and decided to replace the fuel tank which has helped, but now it even backfires/power loss now and then even with a fresh fuel filter so Im wondering if that crap get into the injectors. Ill run some STP and see what happens, and other suggestions are appreciated.
Dan
P.S. bny sorry man for snagging your thread, but i think we pretty much figured out what you want to do.

DR, that makes sense. for a person off the street, it can be a bit pricey to have the injectors cleaned (enough so, that i would personally opt for new injectors), but it sounds like you got a hook-up.

have you pulled codes for fun, to be sure it is injector related?

good luck.