toby'sstang

I am not sure yet how to post on here so I maybe putting this in the wrong place but anyways. I need help!! lol
I need help, I have been trying all kinds of things and reading things and watching things and well I still don't know. lol
I have a 02 Mustang GT that has a small misfire at low RPM's. I notice it more when I change into 5th gear between 45 to 55mph. If you give it a little gas it will stop with the misfire. It also seems to lose a lot of power when the AC is turned on but the AC blows ice cold.
List of things I have checked and replaced.
1, Fuel filter two times
2,plugs two times
3,coil packs, all new
4,checked for vacuum leaks
5,Cleaned the EGR
6, cleaned all the injectors
7, cleaned the fuel system

If anyone could help with this that would be great.
toby'sstang is online now Report Post Reply With Quote

Maddsajin

what kind of spark plugs... ford engines are picky with the spark plugs you put into them... i know that for a fact...

and second how did you check for vacuum leaks... everything else you did is fine to help with this situation...

btw mine still has this same misfire... but i have a intake manifold leak and a head gasket leaking oil... so i am going to rip it all apart next month to replace all the gaskets... i put motocraft copper core spark plugs in mine, they work perfect..

let me know what you done and what kind of spark plugs...

thanks!

youtube video of the seafoam... dirty dirty engine... oil leak..

toby'sstang

The first set I put in were Motor craft plugs that I got from the Ford place. The set that is in it now I put in something different but there was no change in either one. You had asked about how I looked for a vacuum leak. I looked around first then I got a can of carb cleaner and left the car running and sprayed around ever where that I thought I should but never heard any change while running. You said something about a intake manifold leak. How is the best way to check for that? I know I do see a little bit of oil on top of the motor but it is very hard to see it down in there.

Z28KLR

Check Engine light on or flashing? If so, get it checked and post back whatever codes.

I had a similar issue a few years ago, was basically a minor misfire present mostly at idle but occasionally under load, and no cel. I did most of the same things as you - replaced plugs, cop's, cleaned maf, new fuel filter, looked for vac leaks multiple times, dicked around with the egr, etc.... What I ended up doing that cured the problem was close the gap on the plugs from the factory spec of .054", down to .046".

Maddsajin

there is serveral different kinds of motocraft spark plugs... copper core?single spark? platnium? platnium x2? platnium x4? titanium? iridium? ford motors are very picky... my best buddy is a mustang guru, he has told me to only use titanium or copper core... never use platnium "thats what im told" i put autolite copper core single spark in mine. that stopped the hesitation... my misfire is from an intake manifold leak and oil leak. i checked mine from the old time cigar smoke test...

seal off the intake tube.. platic bagy or duct tape will do... then remove a vacuum line connecting from your plenum to your intake tube.. seal off the hole you created with duct take on your plenum. then take a lit cigar and blow the cigar smoke into the tube you are holding... you are basically filling your top end of the motor with cigar smoke...

"dont inhale the cigar smoke just hold the smoke in your mouth then blow it into the tube"...

fill the entire intake with this cigar smoke... once you have enough smoke into the motor, if you have any cracks/leaks in your intake, you will see an escape of your cigar smoke that you forced into the intake... its a very cheap test that will take you about 15 mins to see the results...

If you have any leaks you will see smoke streams from that point... that will tell you if you have a intake leak... let me know what you do...

this is my redneck solution that will only cost you 1$ for a cigar....

try it

toby'sstang

Sounds good that is what I am going to try next. Set the plugs to .046 and buy a fat cigar. lol I will let you know what happens. Thanks guys.

toby'sstang

Well I tried the smoke test and wow it worked. I found about 6 leaks around each hook up for the tubs on the cold intake. So I went to Auto zone and picked up some hose clamps and put on each end of all the little hoses and so far so good. It is not missing. It seems to have more power too. Thanks again. I will see how it does over time.

Maddsajin

awesome news buddy!!! i will repost when i get some gaskets for my heads and intake manifold... i am glad you have fixed your stang... sometimes its the simplest things to fix..

99gt-stang

I'm having the sane issues with my 99 gt, usually under 1200-1800 rpms and even more when its cold and not up to temp yet. Changed plugs to a good quality NGK and appeared tonrund a little better but still did it and after a week or so, it came back pretty bad, that whole hesitation crap. Electrical or fuel. Going to clean the throttle body but not sure what else.
110leaded, could you give some pics on whatbu did? Checked the COPs and connections and seem fine, but in know u don't need to be off much for a problem......

cliffyk

How many miles on it? What sort of driving do you usually do?

Does it have any intake mods?

Did the COP boots smell/appear "burned", were they still flexible?

Also, I would pull the NGK plugs and put in a set of Motorcraft or Champion single platinums--I ran Champion stock #3401 for 7 years and over 85k miles with no problems.

If it is missing under light loads then it could be a sticking/stuck EGR valve...