Can ANYONE please help me..

[Mike97gt]

ohh one more thing.. remove all the wires off the plugs and check down each plug hole.. is there any water or any other crap that sould not be there??

i had a 97 4.6 GT i did a intake too once and same thing your having now.. drove fine and then hesitated and misfired at high load.. and the plug holes had a little coolant in them... must have been from when i removed the intake... blew the water and crap out with compressed air and then it ran fine...

 

[9646gt]

yeah that is kind of weird how it ran well at first...

i dont like the use of aftermarket plugs in ford motors.. use the motorcrafts.. I have had so many problems related too non-motorcraft plugs in the past... now it's the first thing i look for..

when did it first start running like crap.. after or before the first plug change...

plus does it idle ok.. i need too know this too help..

It ran like crap the day I bought it (2 weeks AGO) and I figured it was jsut in need of a tuneup (165k on car but motor seems way to clean and smooth after plug change to be that high) after putting in the NGK plugs (platinum) gapped at 54 and runnin seafoam into a vacume line on intake it ran like it was brand new...am I maybe running to much fuel pressure or running rich? It makes alot of exhuast pop if I let off completely while slowing down or if I use engine breaking it pops alot ...there is no pipe after the mufflers so I can hear that much very well... Thanks for such quick response!

 

[9646gt]

ohh one more thing.. remove all the wires off the plugs and check down each plug hole.. is there any water or any other crap that sould not be there??

i had a 97 4.6 GT i did a intake too once and same thing your having now.. drove fine and then hesitated and misfired at high load.. and the plug holes had a little coolant in them... must have been from when i removed the intake... blew the water and crap out with compressed air and then it ran fine...

Well if it means anything..it does still have the stock intake with the plastic front (wonder if I can get it swapped for free under some type recall) and when I pull the plug wires out they were dry as a bone but they had a little bit of like a brown dusting on them a couple more thick than others...I will also check thos holes and make sure there is no coolant also..it will probably be around 630 or so when I get to really work on it as I am at work right now...

 

[Mike97gt]

It ran like crap the day I bought it (2 weeks AGO) and I figured it was jsut in need of a tuneup (165k on car but motor seems way to clean and smooth after plug change to be that high) after putting in the NGK plugs (platinum) gapped at 54 and runnin seafoam into a vacume line on intake it ran like it was brand new...am I maybe running to much fuel pressure or running rich? It makes alot of exhuast pop if I let off completely while slowing down or if I use engine breaking it pops alot ...there is no pipe after the mufflers so I can hear that much very well... Thanks for such quick response!

the poping from the exhaust is ok..

ok i have eliminated a stuck open valve by the fact that you say it ran like crap and then ran good with new plugs for a little while.. thats good news..

(i have seen a few 4.6's with valves that wont close all the way on 1 or more cyl's and causes misfires)

ok this is what you need too do.. and without a wds this is the best way i can think of doing it..

i think the problem is in the ignition system not the fuel system..

you may have a very weak coil pack or a wire with high resistance.. do you have a firend with a early 4.6 stang.. or any board memebers near you that will let you try there packs..

a weak coil could cause this problem.. the brand spanking new plugs probally masked the problem at first..

one way too diag this with out WDS (power balance test would be great for this) is run the car in 4th gear at very low MPH and step on the gas hard

this will cause a very high load consition and possibly a misfire (thats what we want) hopefully the pcm will pick this up..

see what the code is.. it will be a po30X x meaning what cyl it is 1= cyl 1 etc...

when you get that.. swap that wire with another wire and see if it sets it for the same cylinder when you test again. ( do this near the auto zone if you can)

if it's the same cylinder it's not the wire.. the it's the coil pack.. if it moves too another cyl it is that wire..

if it dont move.. swap the coil packs and test again... if it dont move too another cylinder then get back too me.. you may have pcm problems and we can walk you through that..

 

[CanadaStang]

If you could get the codes read again and let us know what it [they] are. There are soo many things that will give you those or similar symtoms. Also might be a good idea to do a compression [and/or leak down] test, so we can at least eliminate that.

 

[9646gt]

the poping from the exhaust is ok..

ok i have eliminated a stuck open valve by the fact that you say it ran like crap and then ran good with new plugs for a little while.. thats good news..

(i have seen a few 4.6's with valves that wont close all the way on 1 or more cyl's and causes misfires)

ok this is what you need too do.. and without a wds this is the best way i can think of doing it..

i think the problem is in the ignition system not the fuel system..

you may have a very weak coil pack or a wire with high resistance.. do you have a firend with a early 4.6 stang.. or any board memebers near you that will let you try there packs..

a weak coil could cause this problem.. the brand spanking new plugs probally masked the problem at first..

one way too diag this with out WDS (power balance test would be great for this) is run the car in 4th gear at very low MPH and step on the gas hard

this will cause a very high load consition and possibly a misfire (thats what we want) hopefully the pcm will pick this up..

see what the code is.. it will be a po30X x meaning what cyl it is 1= cyl 1 etc...

when you get that.. swap that wire with another wire and see if it sets it for the same cylinder when you test again. ( do this near the auto zone if you can)

if it's the same cylinder it's not the wire.. the it's the coil pack.. if it moves too another cyl it is that wire..

if it dont move.. swap the coil packs and test again... if it dont move too another cylinder then get back too me.. you may have pcm problems and we can walk you through that..

Dude you are awesome I will have to do this first thing when I get off from work...all I want is for it to run normal again lol. I agree that it has to be ignition...if it ends up being a coil pack what is the cheapest solution? I have no real mods that would be helped by an aftermarket coil pack so all I will need is the stock packs but I have seen them only as low as like $50...once again you are awesome help on this problem..may have to paypal you some cash for your effort

 

[Mike97gt]

If you could get the codes read again and let us know what it [they] are. There are soo many things that will give you those or similar symtoms. Also might be a good idea to do a compression [and/or leak down] test, so we can at least eliminate that.

well he did say it ran great when he first did the plugs.. thats why i think it's not a base engine problem.. but your right it wont hurt too check if he has the tools to do it...

 

[Mike97gt]

Dude you are awesome I will have to do this first thing when I get off from work...all I want is for it to run normal again lol. I agree that it has to be ignition...if it ends up being a coil pack what is the cheapest solution? I have no real mods that would be helped by an aftermarket coil pack so all I will need is the stock packs but I have seen them only as low as like $50...once again you are awesome help on this problem..may have to paypal you some cash for your effort

nah don't worry about paying me.. just throw the money you would have sent if this helps into a fund for gears or somthing

i would just get new stock ones if it's one of the packs.. it's most likely only one coil..

i am tring too think of a easier way too test it.. at work i would have tested this with the wds using the power balance and ignition tests..

 

[CanadaStang]

well he did say it ran great when he first did the plugs.. thats why i think it's not a base engine problem.. but your right it wont hurt too check if he has the tools to do it...

True, but he put the Sea Foam in the same time he did the plugs. It may have helped give him a bit more compression for awhile. Kinda like putting a bit of oil in the cylinder of a small gas engine that is very low in compression and won't start. It may be OK, but we may as well start with that.

 

[Mike97gt]

True, but he put the Sea Foam in the same time he did the plugs. It may have helped give him a bit more compression for awhile. Kinda like putting a bit of oil in the cylinder of a small gas engine that is very low in compression and won't start. It may be OK, but we may as well start with that.

it may not be that easy for him too test this.. again at work i could do relitive compression on the wds and know right away..

i don't think the sea foam would have held the compression higher for that amount of time... he said it ran good for a tank and a half... thats a lot of driving..
a compression problem would have reared it's head long before that..

 

[9646gt]

it may not be that easy for him too test this.. again at work i could do relitive compression on the wds and know right away..

i don't think the sea foam would have held the compression higher for that amount of time... he said it ran good for a tank and a half... thats a lot of driving..
a compression problem would have reared it's head long before that..

Yeah all sea foam does is help clean carbon deposits so I dont think it made a huge difference...I have no way really of checking the compression..I wish I did but I don't have the tools and it would probably be pricey to have it done..I only make 8 bucks an hour and after paying rent and 2.41 a gallon for gas and all my other bills that leaves me with like 100bucks or less a week to live on heh...I am hoping its the coil packs..can autozone test them or something?

 

[9646gt]

Ok had the guy at autozone run the codes (KOEO of course) and p420 was the only code ..even did the 4th gear floor at low speed and no codes about anything else came up...i am going to try and find out how to check my tps and maybe thats it?

 

[Mike97gt]

Ok had the guy at autozone run the codes (KOEO of course) and p420 was the only code ..even did the 4th gear floor at low speed and no codes about anything else came up...i am going to try and find out how to check my tps and maybe thats it?

did it misfire on you?? i highly doubt it's the tps.. dont waste your money.. the new plugs would have not masked the tps problem..

 

[Mike97gt]

thats sucks that the computer is not picking up the misfire... (sometimes it takes awile or it has too be at light throttle too pick it up)

the only thing you can do if you cant get the computer too pick up the code is too pay somebody too drive around with you with the WDS on it.. if you do this.. tell them you want too monitor it on the power balance test.. that will tell you witch cylinders is going out on you..

or if you have a friend with a gt swap his wires.. then if that dont work his coils and see if it goes away..

just trust me dont replace the tps.. (it's not going to fix it) see if autozone can get live data on their scan tool.. and check the tps at idle and wide open throttle and post the numbers of both here.. (you can check WOT with the engine off)

BTW the po420 is a cat innefficency code bank 1... ignore that.. for now.

and auto zone will not be able too diagnose the coils..

 

[CanadaStang]

i don't think the sea foam would have held the compression higher for that amount of time... he said it ran good for a tank and a half... thats a lot of driving..
a compression problem would have reared it's head long before that..

Whoops!! Missed that part about running good for a tank and a 1/2, was talking[listening ] to the g/f on the phone as I read that. My bad.

 

[CanadaStang]

thats sucks that the computer is not picking up the misfire... (sometimes it takes awile or it has too be at light throttle too pick it up)

the only thing you can do if you cant get the computer too pick up the code is too pay somebody too drive around with you with the WDS on it.. if you do this.. tell them you want too monitor it on the power balance test.. that will tell you witch cylinders is going out on you..

or if you have a friend with a gt swap his wires.. then if that dont work his coils and see if it goes away..

just trust me dont replace the tps.. (it's not going to fix it) see if autozone can get live data on their scan tool.. and check the tps at idle and wide open throttle and post the numbers of both here.. (you can check WOT with the engine off)

BTW the po420 is a cat innefficency code bank 1... ignore that.. for now.

and auto zone will not be able too diagnose the coils..

Ya that's one of the codes I figured you would be getting. As Mike says, just ignore that and try what he suggests,[if you can]

 

[9646gt]

Well the TPS tested bad on volt meter test i did (voltage was going kinda crazy...AZ tested it with a sensor tester and said the same thing so I replaced it (before reading replies) and like you said even after reseting the computer its still acting up...i hate to sound dumb but what is a WDS? And how much would it cost a mechanic to do that? also They said at AZ the scan tool they have for OBD2 wont work with the motor running...I am so frustrated and broke that it isn't even funny at this point! And I dont really know of anyone that has a set of wires I can test with or coils...only 4.6 owners I know have like f150's and stuff...I have a friend that can get me some loaners but they wouldn't be for a stang ..he may can get parts from other 4.6 cars if anything is interchangeable...It's hard going from a problem free Toyota with almost 200,000 miles on it to this car thats 4 years newer and I instantly have problems lol

 

[CanadaStang]

Well the TPS tested bad on volt meter test i did (voltage was going kinda crazy...AZ tested it with a sensor tester and said the same thing so I replaced it (before reading replies) and like you said even after reseting the computer its still acting up...i hate to sound dumb but what is a WDS? And how much would it cost a mechanic to do that? also They said at AZ the scan tool they have for OBD2 wont work with the motor running...I am so frustrated and broke that it isn't even funny at this point! And I dont really know of anyone that has a set of wires I can test with or coils...only 4.6 owners I know have like f150's and stuff...I have a friend that can get me some loaners but they wouldn't be for a stang ..he may can get parts from other 4.6 cars if anything is interchangeable...It's hard going from a problem free Toyota with almost 200,000 miles on it to this car thats 4 years newer and I instantly have problems lol

The coil paks should be interchangable with the other 4.6's. The newer cars and trucks went to the coil on plug type but the older ones should be the same. Hold tough, we'll figure it out. Swapping out the coil paks is a good start, just label the plug wires before you take them off so you know where they go.

 

[9646gt]

The coil paks should be interchangable with the other 4.6's. The newer cars and trucks went to the coil on plug type but the older ones should be the same. Hold tough, we'll figure it out. Swapping out the coil paks is a good start, just label the plug wires before you take them off so you know where they go.

I just don't understand why the computer isnt picking up the missfire..I mean it is really rough so it just doesnt make sense....hopefully i can get my hands on some coil packs...so do we about have it narrowed down to that?

 

[9646gt]

Whoever owned the car before me has a mess with the plug wires..they are laying on each other and on the valve covers and everything else..can straightning all that out help a little?