High rpm start idle + AT shift

[jjt52]

When I first start this 93 EB Automatic the rpm races to 1800 and then settles down to 800. Then I put it into OD and it races up and settles back down. Driving is fine. When I shift into reverse or neutral or park, it races up and settles down. What's going on?

I stopped at a Ford dealer to check it out to make sure it was OK to continue my trip home. They say it'll be allright to drive but they said it appears that I need a transmission modulator valve, and an idle air control valve. They also noticed a swollen vacuum hose that needs to be replaced. If I wanted it done right then, it would run about $400. That's right 400 bucks.

Could someone explain all this to me? Its obvious that a swollen vac hose should be replaced, but why both a modulator valve and IAC valve? And why 400 clams?

 

[fordkrazy]

replace the hose and the the IAC and see where you stand.....you can check the vacum modulator yourself ....pull the vacum line off of it and if you have tranny fluid in it then its bad...other wise its fine...
but it does sound like its bad
i think that is is an easy fix yourself....not sure...check out a repair manual

 

[Opera House]

Swollen hose

Sure sounds like the vacuum modulator is leaking fluid. That is the only reason a hose would swell up. The Vacuum modulator valve is only about $15 and removes with only one bolt. Unfortunantly, it is not at an easy place to get at. I would consider $200 a reasonable labor charge. On Genl Expl, B94Sport just did this and you can read his experience on Weekend Project. He did his by removing his seat. IAC is about $65 but you probably only need to clean it. So $400 is about right. That's just what things cost if you don't do the work yourself. You definitely need to replace the vacuum modulator very soon or it will cause problems to your engine and transmission.