[cali 5.0]

my 89 gt idles like shit, when its cold it idles real rough and dies after cold start, and when its warm it still idles like shit but it stays on and it is completely stock,

[sAJ1420]

that sucks. good story though

































ha just messin wit u man, has it always done that or just recently start? if recently have you done anything to the car lately?

[99mustang232]

how is the routine maintenace? is this something that gradually got worse?

iac, map sensor, tps?

[Vamp89]

I changed my distributer and used carb cleaner to clean the egr and iac, now she starts right up even after sitting all night.

[cali 5.0]

changed head gasket and i t did good for a while idled like new for a bout a week but its been this way for a couple of weeks and im gettin damn tired of it

[cali 5.0]

do u think that i could have a vacuum leak maybe,,,?

[stang fanatic]

Look around at you grounds....especially where the lead coming off the neg post to the fenderwell needs to be in good condition, and the connector on the fenderwell itself needs to be clean.

[cali 5.0]

also whenevr i launch at 4000rpm it just falls back over on its face the rpms drop dramatically back down to about 1500 and the car starts to pick up speed slowly, and the tires only turn for about a half a second and then the rpms drop..

[stang fanatic]

you really need to see if there are any codes....think i just fixed mine...something similiar here lately....newly replaced iat sensor was bad

[cali 5.0]

where is the iat sensor on an 89 5.0 with mass air flow

[stang fanatic]

in the intake manifold...

[kellyz]

If you have a poor idle in your car... rolling idle...
then you should clean the iac or even (carefully) the maf sensor...
these usually get dirty if you have an air filter like a K&N...
other than that if you still have a rolling idle, it most likely is a vacuum leak, so check or even replace the vacuum hoses at the back of your intake.

[dcraig8]

if the i.a. c. has never been changed, then change it. you will be amazed. cleaning something that is already bad does no good

[Zak]

Please read this article from my favorite technical reference Ford Muscle magazine, it would solve your problem:

http://www.fordmuscle.com/archives/2...in/index.shtml

[HORSMEN1995]

change the I.A.C.... but first i would check the mass airflow sensor

[jsj_297]

Hey bro, you need to take the air bypass valve assy. off of the throttle body/intake manifold. Take and clean the crap out of it with tb cleaner.
(be careful not to F-up your gastket.)

If that dosent do the trick, check your pcv hoses, both of them for cracks in the turns of the hose, man ive seen litterly 20-30 of them that look fine, until you bend them and they are usually gashed to shit. Mainly the one that goes to the front of the upper plenium is the worst though. This is going to give a severe primary vacuum leak.

Also check in general for any other little hoses coming off the upper plenium intake. Ive had to replace dozens of them over the years on various yrs/makes of 5.0 engines.

hope that helps some.

[NYHigH]

if i were you i'd give it a regular tune up ...
spark plugs
wires
distributor cap and rotor

then start from there and check the timing

[NYHigH]

i didn't see all the responses at first bro.... your onto something

[homebrewed]

Tune-up, air and fuel filters, clean your sensors CAREFULLY!!! w/ parts cleaner, check for a vacuum leak and see what happens.

[GTXRacing]

"Hey bro, you need to take the air bypass valve assy"

Don't you mean (essay)?