Idle problem... :( thanks

[Caldwell]

Hey,
just recently... say, within the last 2 days, I have been having weird Idle problems with my car.
Generally I have it set to 600 rpm, which I think is relatively standard for a normal idle, however I've come across two problems, which I hope are related.

my first idle problem happened when i turned on my car, and took my feet off the clutch and gas, while having it in neutral, the car's rpms slowly fell and of course the car died. now me thinking it to be a fuel issue...
about... 15 minutes ago, my car started a new idle technique
now it was going from 600 to a 1000 rpm then back down, up, down, up, down... and so forth... in maybe 1 second intervals...
i'm clueless.. and i don't know if it would be because of humidity? whatever...
i'm lost please help a guy out.
this car keeps poppin up with small problems it seems on a daily basis.

 

[mo_dingo]

Weather is unlikely.

Has the check engine light came on at all? Even if it hasn't, you might want to run the codes anyway. Go to the EEC-IV Tech section of www.allfordmustangs.com and it will show you how to run the codes with a piece of wire.

Also, do a search here on how to clean your MAF. Also, you can check your dist. cap/rotor, wires, & plugs for abnormal signs. Excessive corrosion on the cap/rotor or anything except a dirt brown color on the spark plugs could be a sign of a problem.
Scott

 

[VIPERn94Five-0]

the bouncing revs could be from a vac leak...check that...


Anthony

 

[Caldwell]

It did throw a check engine twice, but didn't happen when I was having the idle problems, so I figured it was coincidental...
the check engine popped on then off again pretty quickly, so I'm leaning towards that to just be my o2 sensor.

but I will definitely run the codes for that.

But thanks for the suggestions guys
It looks as though today is trouble shooting mustang day hah
work... you can wait! I have an important meeting to attend with a 94gt.

Thanks again

Doug

 

[Caldwell]

I went ahead and checked the vac, and it ran steadily in the 20s
I figured with a vac leak though it would run rough, and stutter a bit while idling, but when I had my rpms go from 600 to a 1000 and back down again consistently, it was a smooth transition...
Now I had gone ahead and reset my battery, does anyone know how many key starts it might take a car to regain all its memory?
Like its' ideal idle points etc...?

thanks,
doug


ps: I went ahead and checked my ignition too, it fires off fine, and fuel is definitely not a problem... but this smooth height and decrease in idle is weird.

 

[SN95Oh]

Probably Idle Air Control Motor