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Discussion Starter · #1 ·
I've got a friend who's gf drives a Mercury Topaz. Neither of us know much about troubleshooting automatics, so I'm hoping some of you will have an idea.

Apparently, every now and then, when she drops the car into Park or Neutral it will rev up really high. I don't know much more than that right now (she's had some trouble describing it,... girls :roll: ) and I don't even know how long it revs up for, if it needs to be shut off, or if it only happens when shifting from a gear or if it will happen during startup. Wow, I guess I'm asking for a small miracle.. from you guys now :?

Does it sound like something any of you automatic drivers/fixers have experienced? I'll have some more details tomorrow, I hope.
 

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I think I may now have the same problem. Ten year old cars, gotta love 'em. It will take a while as my time is limited, but when I figure it out I'll let you know.

Matt 8)
 

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Discussion Starter · #5 ·
I got a chance to chat with her tonight. She said it only happens when shifting out of a gear, never when starting up. She doesn't know how high it revs (doesn't bother to read the tach... girls :roll: ) but she said "about medium revs" and when it occurs she shuts it off quickly. She said it usually happens when she's been driving a while.

Now, isn't there a secondary idle adjustment for the idle under load from the tranny when you have an automatic (so that the 800rpm idle in neutral will become 800-1000rpm when in gear)? Wherever this second idle position is.. I think it's getting stuck at that point for some reason and won't drop to the primary idle speed.

Anybody with me?
 

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pballer98c said:
no clue.... but ya might wanna try changing ur tranny fluid. later
Changed it about a month and a half to two months ago.

I hear what your saying Beaverboy, but for me to try and find the time to trouble shoot it is hard since I'm back in school. Like I say, I'll let you know when I find it, but hope that you find it first :wink:

Matt 8)
 

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well this happens to me everyonce in a while, and i belive it happens to my brothers neon. And his is a 2001. So ive heard of this happen all the time, and i think there is a second adjustment on mine. But as far as know, as long as it drops back down there is no real problem, sometimes it just does that. This guy at king said bring it to them, no duh right? anyways and get the 70% fluid change, and flush most of the system, not just whats in the pan. And he said that would fix any gunked up shite in the valvebody. This is all i know and its only in refrence to a saturn...so take what u will
 

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zzyzzx said:
I'd check the TPS if my car were doing this..
I have a new one on there :roll:

Should I check my IAC :?

FYI- it was my intake manifold that was leaking, not a bad IAC.

Matt 8)
 

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Success :D

Got some time to diagnose this thing, and I have found the root cause of this problem,

Bad grounds to the tranny.

There were a few grounds on the tranny that I missed the last time I was 'ground cleaning.' Cleaned and sealed them up. Good as new :D

I also had the battery disconnected long enough to let the ECU reset, but I know that was not the problem because I have had the battery disconnected before for long enough, and it still acted up after re-connecting.

Stupid salt and corrosion :x

Matt 8)
 

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Sorry to dredge up an old topic, but that's what happens when you use the [Search] button before starting a new topic... ;)

Tonight, for only the second time since I've owned my Escort, I experienced this exact problem. Both times, it was after I had been driving "at highway speeds" for an extended period of time (ie: more than a couple miles). As I press in the clutch in preparation to stop, the car revs up to about 4000 rpm (and stays there!!) until I put it in gear again. Even if I use the tranny to "brake" a bit, and the revs are around 1500 - 2000 when I depress the clutch, it still climbs to 4000 when I take it out of gear. I parked the car and shut it off, waited a few minutes, then it worked fine. The problem does not appear if I travel at high speeds for short periods of time, only after I've been driving for a while. Tonight's experience/experiment demonstrates that the problem occurs whether or not I've used the cruise control at any point during the trip (I did use it a few weeks ago when the problem first presented itself, I was not using it tonight when the problem occurred).

Obviously, something isn't working correctly... what should I check? If you know (or think you know) what part (or parts) is (are) failing, what can I expect to spend to repair the problem?
 

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Mine started doing this about a month ago. If I step on the pedal the revs increases. If I shut of the engine and restart the car it's fine. I think it may be the Idle air control valve like fixitmattman said.
 

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DAPSi said:
Mine started doing this about a month ago. If I step on the pedal the revs increases. If I shut of the engine and restart the car it's fine. I think it may be the Idle air control valve like fixitmattman said.
So if you step on the pedal, the revs increase? Huh, who'da thunk? :wink:
 

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So if you step on the pedal, the revs increase? Huh, who'da thunk? ;)
Heheh.. I think they meant that the seemingly static very high "idle" speed increases if you rev it up in neutral. Mine was static at about 3300, and I kicked it to see if it'd go back down to "normal"... instead, it just "stuck" at a higher RPM (4000).

Perhaps it is the Idle Air Control Valve... I'll have to dig out the service manual and research it a bit more, I guess.
 

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Okay... well, I checked the service manual, and there are three different IAC assemblies that might be used on my car. The first is made by Hitachi and can be cleaned; the second is also made by Hitachi but cannot be cleaned; the third is made by Nippondenso and cannot be cleaned. If you have the first type, the instructions say that the cleaning procedure is in the service manual (although I couldn't find it!). The other two types need to be replaced. Odds were against me, and after checking my IAC against the illustrations in the manual, it seems I have the second type that requires replacement. :(

$49.00, and my local auto parts store will have one waiting for me in about 25 minutes -- so I need to get over there (they also close in 25 minutes). I'll replace it this afternoon, and I'll have ample opportunity to see if it cures the problem as I'm taking my car to West Palm Beach to visit my sister for the holidays. Will report back here after the test(s) are finished.
 
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