naturally your rpm's will go up when you drop it into neutral, because the engine meets no resistance with the transmission. Now do the RPM's drop when you slow down while in neutral or is the car still in gear when you deaccelerate?
Runaway Rpm's
98' Duratec, out driving today and still experimenting with hesitation issues (dealer thinks I'm nuts), so driving around 40mph, RPM sitting at 1,500 drop the car in neutral and RPM's go up to 2,300 and engine is reving higher and it will stay like this until car slows down then RPM's start to drop. Is this NORMAL? Or is there something wrong with a sensor or vacuum leak? Trans. was rebuilt in December wondering if they screwed something up while working on it. In previous cars when transmission was put in neutral the RPM's (and engine) would return to idol position, not rev up. :angry:
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car is not in gear (still in neutral) as I decelerate (apply brakes). Just took my Explorer out and followed the same procedure, as soon as I put it into neutral the RPM's and the engine speed went to idol position. It did not rev out of control like the Sable is doing.
make sure you don't have cruise on or anything. for some reason is isn't smart enough to tell if its in gear or not, if you are cruising, and you shift into N, then decelerate, the cruise will see you slowing down and rev the engine trying to speed up, but being in N it can't do anyting about it, so it just revs. also, try resetting your battery. my car has done that from time to time, as a result of poor communication with my Apten chip, so I know that computer problems can cause the idle to shoot up like that. with mine I just turn the car off and on again, then its fine. I assume you don't have a chip, so maybe the computer is confused. pull the negative battery lead and leave it off for a while, allow everything to reset, reconnect it and go for a spin, see if the problem returns
No, no chip (on my wish list though 
), pulled batt. cables twice to reset computer and still doing it. The cruise control is not engaged when I do this. Like I said, every car I've had has always returned to idle and so did my explorer yesterday. Took my friends Crown Vic out last night and it also returned to idle when placed into neutral. I agree that the computer is lacking communication but it has to be stemming from a sensor I would think. Just not sure which one.
), pulled batt. cables twice to reset computer and still doing it. The cruise control is not engaged when I do this. Like I said, every car I've had has always returned to idle and so did my explorer yesterday. Took my friends Crown Vic out last night and it also returned to idle when placed into neutral. I agree that the computer is lacking communication but it has to be stemming from a sensor I would think. Just not sure which one.Might be a bad VSS. (vehicle speed sensor)
Thanks, I was wondering about that. Going to a "different" dealership tomorrow and have diagnostics run and hopefull they can pin point. Cleaned MAP sensor today and that didn't seem to help any. Will update with dealership find.
UPDATE, two hours diagnostic at dealership turned up NOTHING. Techs searched for everything. No codes, every sensor, pump, etc. working to specs. Only one possible problem. Since car is only acting up when the ambiant temp. is above 85 they think it is fuel pump related since the gas tank is closest to the ground BUT without being able to verify a problem, warranty won't cover replacement. So, I'll keep driving until it tears up or I push it off of a cliff
What you are describing is NORMAL, programmed behavior. The rpms will hover there until you put the car back in gear or slow down. This is so that there is no jerking of the engine and drivetrain when you put it back in gear. I'm not sure what year this was implemented, but it IS intentional.
That's right, both of our Bulls do it to. 2 hours of diagnostic work at the DEALERSHIP for something that they should know is normal behavior??? Hope you didn't have to pay anything.Originally posted by SixFoFalcon@May 18 2004, 12:03 PM
What you are describing is NORMAL, programmed behavior. The rpms will hover there until you put the car back in gear or slow down. This is so that there is no jerking of the engine and drivetrain when you put it back in gear. I'm not sure what year this was implemented, but it IS intentional.
Yeah, I had to pay :angry: They can see me coming a mile away!!! Thanks for the info. Did more research through a friend of a friend who works at Ford and you are right, these cars are programmed to do that. The MAIN reason for my taking to dealership was due to hesitation upon acceleration in stop and go traffic, but couldn't find anything wrong with that either. I thought maybe the two were linked together. Tech thinks it may be fuel pump heating up in tank and starting to break down (especially since it only happens when it's hot outside) but he couldn't get it to act up or shot a trouble code. So, I'll continue driving and convince myself that I'm just crazy and it's really NOT hesitating :banana:
And I think the tech is full of :bs:. If that was the case, it would be much more obvious when your tank is on "E". The fuel pump uses the gas in the tank as a coolant. Ambient temps make little if any difference to the pump.Originally posted by gruffybear@May 19 2004, 04:10 PM
Tech thinks it may be fuel pump heating up in tank and starting to break down (especially since it only happens when it's hot outside) but he couldn't get it to act up or shot a trouble code.
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