Stangnight

Well, first of all i would like to thank you all for your efforts, i'm new to this forum so i have to say i love it already, you guys are awsome!..Gaspi101thanks man i'm happy to be here.

Ok, i got th IAC, fuel filter, upper manifold gasket along with other things like transmission oil & filter (i just had to i mean i don't know what the previouse owner did or did not change u know). you see I work 12 hour shifts at the moment so i don't have much time to do anything. My mechanic called me up while he was workin on it yesterdayand said that there was a leak in vacuum hoses inside intake manifold and so they had to be replaced along with a T joint connection thing!! ( not sure where exactly or what it is, please advise!!!)so anyway gotmy sis to get those for himand i pick the car up the same day after work.The engine seems to be running more smoothly and responding better. i test drove it and went back to him and stoped putting it in N as put it in D again the RPM fluctuated slightly AGAIN, i was raging!! it didn't do it again till now though. It doesnt do it after start up Gapsi u see i drive to work every morning and the car is completely fine, only does it after beeing run for 2 or more hours!! i guess TPS and PCM are next to be checked ha!..u see the thing is, i could be driving the car for three days or sumthing with no problem! all of a sudden t'll come back, but now i think i'm sure that it only happens if there a load on the engine i.e. running up to more than 2 hours !!

P.S. the guy advised me that if the problem is still there then i should replace the fuel pump, till then i have to keep fuel leve up to half tank most of the time for the fuel pump not to heat up, doesn make sense to me so i aint lestining!! what do you think?

thanks again peeps!

Stangnight

oh yeah GodAmGT00, i replaced the plugs last weeks but not the wires. and i don't get check engine light!!!so i guess i don't have a serious compression problem right!

GodAmGT00

I'm not sure about the fuel pump over heating, but it's always a good idea to have a fair amount of fuel in the tank, for several reasons.. I'm also unsure as to what your mechanic meant by vacuum lines inside the intake manifold, but maybe he meant outside the manifold.. See if he'll tell you exactly which ones he replaced..



JT

Gaspi101

I remember taking my motor apart, and I know for a fact that there are no hoses inside the intake manifold. Just ports to the cylinder heads and ports for the coolant. If there was a leak, and it had to do with the intake manifold, it would have been an manifold gasket, but again, there should have been a "check engine" light on--the computer is very sensitive to cylinder misfires. Also, I'm pretty sure that this could never be a tune-up problem (cables, plugs, fuel filter, etc.) because none of these would cause you to rev to 5000 rpms and back. It's a good idea to always have these things taken care of, but I don't think that's your problem. If the mechanic says that you have to keep a lot of fuel in the tank, he's making stuff up.

We have to look at things scientifically--You say the problem comes up when the car is driven for 2 hours or so, or when there is a load on it. Let's eliminate one. Start the car up in neutral, and leave it there for an hour or so (gasoline prices should be no problem for you!!! HAHA). If the car has no problem after it reaches running temperature, then it's more probably a load issue. We want to separate the two (load/temperature) because these can lead to different diagnostic theories. Load: PCM/TPS, Temperature: Electronics.

And I also work 12-14 hour shifts, so I know how that feels!!
Let us know what happens!!!

Gaspi

GodAmGT00

I'm still wondering why it's not throwing codes.. Maybe the bulb is burnt out??


Other cars that I've had, that have similar issues (although some of them were 5-spds), with hunting or RPM fluctuation lean towards bad IACVs or TPS errors... That's usually in neutral though.. In drive gears, it tends to be PCM related... I hate blindly stabbing at this though..

Stangnight: Do you have a way to videorecord what you're doing and what the car's doing, post it up so we can have a better idea??


JT

Stangnight

ok, forget what the mechanic said i too think he's making things up!..the car is fine so far, but i don't really drive it a lot now only to work and back. my hours will go back to normal in bout 3-4 days ( silly plant shutdown!!) then i can test it properly. yeahgas is cheap here man, about $ 0.27!!!!! will try that, although i'm certainthat the car is fine whenit reaches running temp. i'm sure its a load isuue but thats a goodway to start. car is shaking a littleduring warm up, approx. 1 min or less after start up,is that normal?. yeah, video is a good idea! i'm hoping i wouldnt have to though!! we'll see what happens. Guys iam i in the right zone todiscuss this cuz i just realised this is a 4.6 GT zone!!

SN95

rjd2

Hello all, i think that i have this problem. I uploaded this video, and if someone could give me their opinion on if it the IAC, that be swell. Thanks

http://media.nscdn.com/uploads/membe...e_20081127.wmv

**** Edit. This was the problem, cleaned the IAC and it runs good. thanks

Pure Shadow77

THANK YOU SO MUCH!!!!! lol ive been wondering wtf it was i had a feeling it had to do with the control valve and i even called my local ford and they wanted to charge me $120!!!!!! for a new one!!!!! ty for the quick fix!!!!

mik3v

cool. mines done this a couple times. ive seen people say they can just clean the crap outa it all all that stuff.
where is it located? what is it called that i need to clean?
thanks.

a link or some details on how to do this would be nice.
thanks