I had the stalling problem a few of us on here have had that includes really poor idle and return to idle. Example - I'm cruising at approx 40mph and approaching a light or going downhill and shift into neutral. RPM's drop and car stalls out. Next time I'm watching the RPMs, shift into neutral, RMPs drop, I bump the throttle RPM's flucuate irradically and then drop/stall out.

I pulled the CAI and cleaned the throttle body, PROBLEM FIXED! ... for one day ...

Now what? Any other suggestions? I just checked the TB again, it's clean - wiped it all out and it's clean.

Wasn't there a TSB out on this at one point? I've had this problem w/ different tunes and don't think that's the problem. I was thinking the fuel pump at one point, but don't know if that would cause the funny RPM's problem? What do you guys think?

 

Try reloading the tune. Since you cleaned out the TB, the car may not know how to act since it was so used to compensating for the dirty TB. It can learn, I know...but I wonder about it's ability to "learn" when something is changed quickly, rather than gradually.

 

Also, clean the MAF sensor, and make sure all of the CAI's connections are tight
.

 

Does it only happen after driving for sometime? There is a TSB for the fuel pump after cruising at speed.

 

Issue from TSB 06-9-9:

Some 2005-2006 Mustangs may exhibit a hesitation on acceleration after a long cruise. After coming to a stop from a highway type cruise, some vehicles may experience a hesitation when the customer begins to accelerate. Air bubbles can form around the fuel pump during a long cruise and be ingested into the pump on acceleration causing a hesitation.

 

So what ever happened? I am having the exact same problem you mention, and cleaning my TB did not seem to do the trick. Did you ever manage to figure it out?

Tim

 

No. It's still stalling. I've had the fuel pump and throttle body with TPS replaced by the dealer. They also checked and verified there are no exhaust or intake leaks via computer monitoring the air/fuel ratio's (I think). I've tried different tunes and have verified that they are working (but still don't solve the stalling). I've cleaned the MAF. At this point I think it's the CAI. I went with the 95mm intake instead of the 80. The 80 doesn't 'require' a tune, the 95 does because of the extra air intake... but yes I've verified the tune and levels are correct. No MILs.

It's frustrating. When I get some free time and it gets warm, I'm going to swap back to stock. (WMS intake isn't a 10 minute project) I'll see if maybe that solves the issue. In the mean time, let me know if you swap back the stock airbox and tune, and let me know if your problem still exists! Have you done any troubleshooting yet? I've been working w/ my dealer mechanic, both Brent and Seth @ Brenspeed and Shannon @ WMS. 4 excellent knowledgable guys, and 1 noob (me), and we can't figure it out.

 

Hey Tim - Here's another thing... grab your X-cal and try to read your vehicle's strategy. Mine won't read it. Everyone says it's probably an unrelated incident... but check for me... who knows - the X-cal maybe's doing something goofy. Do you know how to use the X-cal to check?

 

I *think* my throttle problem is fixed. After reverting the car back to stock and disconnecting the battery the problem seems to have subsided. When I cleaned the throttle body I never reset the computer and the problem still existed. I am led to believe that it took both a good cleaning and reset to resolve the problem. After I ran it stock I put my CAI and tune back on the car and it seems to be doing fine, but I’ve only taken it for a quick spin a couple times since then.

I do have one other issue which I think is related and still leaves me concerned. When I’m cruising around 60, and go down a slight incline or ease up on the gas so I am barley on it, the car seems to be stuttering or hesitating. It feels like its being starved for air, gas, or both. During these times the RPMs do fluctuate as well. Have you experienced anything similar with yours? It’s almost the same feeling you get on a really windy day, however the wind would not cause RPMs to fluctuate would it?

I’m really frustrated with it right now. I keep driving around trying to figure out what it might be to recreate the problem and it’s just not consistent enough to nail down. In stock form the darn tranny is too mushy to feel anything, so I can’t see how I might possible recreate it for the dealer. Car seems perfectly fine otherwise.

Before reverting to stock, I was convinced I was going to have to take it in and I hooked up my XCal to read the strategy code which it did without a problem.

Tim

 

I haven't noticed any problems with inclines or elevation. Good luck. Hopefully it doesn't become more and more frequent like mine did. Mine happens much more frequently in cold weather (part of the reason I think it's intake related), luckily you're in TX and not OH.

 

Have you had your fuel pump replaced?......I had mine replaced under the TSB on it!

 

I sure have. This hesitation is much less pronounced then was the fuel pump TSB hesitation. This is a choppy feeling almost like its missing.

Tim

 

Did you try cleaning your MAF? I just cleaned mine up and I think that may have done it!

Tim

 

Been there, done that

 

I'm hoping mine is fixed, but I won't rest easy until I drive it a few days and don't have any more trouble.

It sounds like you have done everything but return it to stock which is discouraging since your dealer is working with you despite the mods, returning it back to stock will not necessarily get it fixed. Maybe whatever is causing the problem will simply break so you can finally identify it!

I can’t imagine it being the intake, lots of people do have the WMS and if the design was a problem I am sure someone else would have chimed in by now. I’ll drop back in a few days to give an update, wish me luck and I wish you good luck with yours in the meantime.

Tim

 

Thanks!

 

Well today it's back with a vengeance. It's colder today then it has been in a while, perhaps the cooler temperatures make the problem more pronounced. I have both the hesitation and surging/erratic throttle. I'm not really sure what to do next. Does anyone else have any suggestions as to what else I might try?

Tim

 

Man, you've tried about everything I feel for ya!

 

As I said, mine's more common in cooler weather too.

 

05GT-O.C.D.,

Reinstall the stock intake, and see if that fixes things. I've read that the WMS intake can cause air turbulence problems with the MAF sensor on the S197's because of the short length of its intake runner.