runs rough when started soemtimes
 

my 93 xlt 4.0 has been acting a little strange lately. when i start it sometimes it will struglle to idle. if i rev it up it seems to be ok. i dont know y its doing it. it does not do it all the time but when it does it shakes bad n stuff. got ne ideas on what to do?

dirty air filter? fuel pump? spark plugs? plug wires? dirty mass air sensor?

the fuel pump is good so is the air filter new plugs and wires mass might be dirty n how do i clean that? could it also be my throttle pos. sensor being dirty?

check your t.p.s. or your idle cotrol motor. not sure if thats exactly right but just thought i would suggest sumthin

thats what my auto teacher said. the thing that buggs me is that it does it on randome occations. sometimes when its hot or when its cold or sometimes when i have it off for like 10 min then i come back and it idles rough

yea there could be something sligthly wrong with ur idle control motor if it only does it on occasions its prolly gettin ready to give out i would take it to the dealer and have them look at it. is your check engine light on or anything

no engine light or ne thing i thik that what i will do is a full comp test on it and have it show what else is wrong with it

clean the throttle body and idle air control valve.

got ne idea on how to do it cus i dont wana mess it up

yea i was gonna suggest to do the full engine test and stuff so maybe it would bring up ur problem

cause i was gonna say i have the tester and stuff and u live close to me.

i think thats what i will do at school tomm and then find out what i need to do

good thinkin lemme kno what you find out

use throttle body cleaner (not carb cleaner) and spray the throttle body with the engine running. also it doesnt hurt to wipe the insie of the tubes...

to clean the IAC, remove it from the throttle body and just use the same throttle body cleaner...also helps to have a few q-tps or junk rags to wipe it out in the inside...

i did that today and so much dirt and grime came out but now it runs great it sounds better and the response is a little bit better


thanks guys

no problem!

So what do I use to clean the MAS?

Brake cleaner... or compressed air...(keyboard cleaner)

mmm endust



i would never do that stuff to get hi it could kill u the first time and i knwo someone who died from doin it

what did it sound like before? Mine sounds like marbles rattling, and the idle is up and down, i wonder if i have the same problem?

thats what mines been doin but it sound more like plastic rattling; I'm gonna try the air stuff :)

ya mine is making some kind of funny noise

does the rattle come in under load like climbing a steep hill?

also i recommened everyone try Seafoam. it'll clean out the top end of the engine, mostly the carbon build up on the valves and intake passages. runs about $5 a can and u put it in slowly through the brake booster vacuum line with the engine running. be sure to pour a small amount in at a time so the engine doesnt die.

use 1/3 to 1/2 a can and let the motor off for about 20 minutes. then start it up and hold it to about 1500-2000 rpm until the exhaust doesnt smoke. repeat and proceed to change the oil.

most people noticed a difference with this and some others havent.

make sure to change the oil after and do it where people dont mind being smoked out :)

I get a kinda tin can ratle type of noise also but only when Im going about 25 or faster.

could be the engine pinging, i think i read on here some of the 2001 and newer 3.0Ls had a problem with that :shrug: