996r916sps

Anyone out there own a manual transmission V6 Mustang?

I have noticed that if I am coasting in neutral with the clutch out the rpm's climb to around 1500 rpm or so, but if I push in the clutch is goes back down to idle speed around 750 rpm. It also returns to the normal idle speed when you come to a complete stop, and if you are just rolling a little it is at about 1000 rpm. What gives?

I am assuming the vehicle speed sensor and the fly-by-wire throttle are the culprit. Just wondering if anyone else has experienced this issue.

Thanks!

burdweiser

mine does the same thing.

BigFloppy

Stupid question: What's "coasting"... If I drove a stick (mine's an automatic), the car would hardly know what neutral was...[sm=bounceybounce.gif]

wheelguner

What you are expierencing is the how the "drive by wire" throttle body is programed to help the car meet emission standards. The good news is that it will go away with a good aftermarket "tune" I purchased my Xcal2 from Doug at Bamachips.com and his tunes can best be discribed as magic. If you don't do anything else to your car...... get a good custom tune. The differance in drivability AND performance has to be felt to believe it. Best money you can spend and your Xcal dealer can email you new tunes as you make changes at a later date, or the latest version of the Xcal will allow you some changes to your programming with the flasher as well.

StickDriver

"Just wondering if anyone else has experienced this issue".


+1

ScottRNelson

My V-6 manual transmission convertible also does it and I find it annoying. Clutch position seems to have nothing to do with what rpms it wants to be at, only car speed. I've seen the engine stay as high as 1800 rpms, usually around 1500 rpms, and sometimes only 1200 rpms. The engine speed drops back to about 800 rpms as soon as the car comes to a full stop.

The issue I have with this behavior is when going down hills. Sometimes I go down fairly steep hills and I would like to use the engine braking to help out. I don't get nearly the engine braking with the throttle open enough to run at 1500 rpms as when it's closed all the way. After a few seconds of coasting down the hill and still needing to use my brakes, the engine will finally start holding the car back like it's supposed to. The biggest problem with this is that it's a bit unpredicatable. I can't be sure when the throttle will finally close and give me an additional dose of engine braking.

This issue has come up before, but I have not seen a reasonable solution posted yet. Vague references to taking it to a speed shop don't quite help. Those of us who want to keep our cars totally stock and don't want to risk voiding the warranty in any way don't seem to have a good solution.

I've talked to my local Ford dealer about it but they just shug their shoulders and say there is nothing that they can do.

If anyone actually has a solution to this throttle issue, I hope they'll post information about it on this thread, with the specifics.

996r916sps

I spoke with a technician, and Ford programs it that way for emisssions reasons. The dealer isn't knowledgable on this, they only know what's in the book. Don't buy into just having someone fix it with a tune. Make sure someone has experience with these types of drivability issues first. I'm sure before too long, it will be addressed.

Thanks for everyones comments!

StickDriver

I don`t understand how this RPM concern does anything for emmissions during coasting. The engine is not under a load. I`m not extremely familiar with my Mustang yet. It seems like to me that there is some sort of feedback occuring during coast. i.e. the speed sensor indicating movement and thus causing a surge in RPM. I wonder if there will be a recall?

ScottRNelson

I remember cars in the 70's when they first started to get serious about emissions. They had things that prevented the throttle from closing all of the sudden. It took a second or two for them to go all the way closed. But they had a physical part next to the carburetor that you could adjust if you didn't like it. Supposedly, the engine doesn't burn fuel as completely if you suddenly clsoe the throttle fully from higher speed.

I still think Ford has screwed up, though.

Maybe if enough of us complain about it they'll find a solution. Who at Ford should I write a letter to? I've already given up on the local Ford dealer doing anything.

wheelguner

I wish to expand on my earlier comment regarding improvement in throttle response and improved drivabilty after flashing a new "tune" to my 5speed V6. In stock trim it was extremely difficult to drive with any degree of smoothness in Atlanta's stop and go traffic. In these often inch at a time driving conditions the engine speed would stay high or actually increase at times then it would slam the throttle shut....... jerk city. I just plain love to drive a good manual transmission, clean performing car and use the transmission for braking as much if not more than the brakes. Doug's (of BamaChips) tune made almost all of this GO AWAY! I didn't trust just any tuner, I spent many hours doing research before choosing him, he has years of experience working on the 4L V6 engine in Rangers and Explorers and is well known among the owners of those vehicles. If you will do a bit of searching on the various forums and read some of the articles in the Truck related mags (the current issue of 4Wheeler has an article mentioning Dougs work on one of their project Rangers) you will discover that I am not alone in singing the praises of improved throttle response on our drive by wire engines.