Idle Problems With Xr6t's

[Zeke]

Well, I've got a diff whine between 95 and 100kph and I do know a diff whine when I hear one. Still deciding whether or not to go for a repacement. Would really be p*ssed off of the outcome was the same or worse than it is now.

[simmo]

for all who have had problems with poor idle and stalling..

try cleaning the battery terminals . im serious it could be the problem.The ecu needs a good voltage and amperage supply,you may have 12 volts at the battery but if there is a dirty connection you will have low amps ,which does all the work .

But I am not doubting that some cars are having ecu problems..anyway it may help.

[ktford]

Scott sits silently in the corner, prays that gremlim will leave him alone if he doesn't move. Mine stalled when it was 1 week old & hasn't repeated it since.

Scotty

[SR-71 Blackbird]

for all who have had problems with poor idle and stalling..

try cleaning the battery terminals . im serious it could be the problem.The ecu needs a good voltage and amperage supply,you may have 12 volts at the battery but if there is a dirty connection you will have low amps ,which does all the work .

But I am not doubting that some cars are having ecu problems..anyway it may help.

Normally with dirty connections on a battery terminal you get a voltage drop acroos the componentry. This in turn increases the current draw of the system. Most mordern day car these days have voltage regulation on the computers which will sense the voltage drop and compensate with an increased cuurent draw to allow the sytem to pull the voltage up to a usable voltage. Don't quote me on this, but I believe most ECM's use a lower voltage than 12 volts. Which allows for a more stable supply to the ECM.

[Guest 01 XRT]

This problem has been happening to all models of the BA up here in FNQ, and it has been traced to the purge valve from the fuel tank to the manifold sticking open which more or less causes it to flood.Apparently they are only supposed to open under throttle and close when backing off or idling. My dealer knows it is a common problem and replaces them no hassles. Haven''t had the problem since.

[axw01]

I've had the purge valve replaced twice now and still no difference. This is definitely not the fix.... unless I've had two dodgy replacement purge valves???.

[ktford]

Hey Al,

doesn't break down off idle. he he

Scotty

[axw01]

You're right about that Scotty!!!!

Al.

[poida97]

Hot off the press guys.There are new calibrations becoming available possibly by christmas or not long after.We're waiting for them to be verified and then despatched to the dealers.Unfortunately the verification isn't the fastest procedure in the world.But Ford are aware of the problem and have produced a fix for it.I will try and let you all know what the actual problem is or was as soon as I recieve that info.

<{POST_SNAPBACK}>

So what should I be asking my local dealer to do to fix this problem?

Anthony

[xlnt6]

Hi All,

I was surprised to see this thread and how many people appear to be suffering the same "stall at low RPM" problem. My car is a 08/03 build and is a manual XR6T.

Reading thru all the posts I see the classic symptoms that I have as well are shared by most others:

1. Problem is worse when the AC is On and the higher it is set (ie Max). I think this is due to the extra load the compressor places on the engine. Many factory setups switch off the electric clutch on the compressor at idle, to prevent this, but it seems the BA set-up keeps the AC clutch engaged at least during initial de-acceleration (ie letting off the throttle, from cruise).

2. As per symptom 1, the problem will occur at the lights, especially as you approach a "red", push in the clutch, and whamo, the idle drops to about 500 RPM and stalls.

3. The problem gets worse, the older the car is. Mine has 53000km on it, when it was new (and standard), it occurred very infrequently, maybe five times in the first 25000kms. Once I got to 40000km it was happening every time I went for a drive.

4. The problem is worse (seems to be anyway) with an interceptor (ie Xede, or Unichip, etc), cause the base mixtures are influenced by the interceptor under the conditions described above (usually for the worse).

I noticed someone has suggested and posted that the problem is due to the engine getting an overly rich mixture under the conditions above, and thought this was due to the purge valve sticking open. Effectively flooding the motor and stalling it. Irrespective of if the purge valve is to blame, I think he's got a point. Fuel vapour will be greater when the AC is On, cause it's "hot outside", so the fuel in the tank has more vapour being produced due to heat.

Also my problem occurred more when the fuel level was very low (ie tank empty, hence more volume for fuel vapour), or just after I filled it (again, fresh aerated fuel pumped in = more vapour).

The reason I say this, is that I have a TSI Pro interceptor fitted. I used the inbuilt diagnostics, and with some help from a friend (one driving, one looking at the laptop), I was able to "see" where on the map the "problem" was occurring. It seems (on the TSI anyway), that on the 500 RPM map at high vacuum settings, the fuel map needed to be reduced by about 5% injection time. Also I "smoothed" the ignition timing at 500 RPM as well, following it down from the 1000RPM map settings, but uping the advance from +0deg on top of base timing, to +2deg. Originally it used 0deg across the entire 500 RPM vs load map. Initially I changed the iginition timing only, but that didn't fix the problem. After changing the fuel map the change was immediately noticeable.

Anyway after doing so, I tried to get the problem to occur, and while the idle RPM still dropped when the clutch was engaged, the RPM wouldn't drop as much (down to about 600-700 RPM) and the car wouldn't stall at all. The car so far has never stalled again in 5000 km.

So I think (my opinion only), that the OEM base mixtures under these conditions aren't quite right (for that ECU firmware version = 08/03 build at least), and if you have an interceptor you may be able to "fix" this OEM defiency. I don't have a XEDE or Unichip, so I don't know if the info above can be applied to these interceptors or not. If your car is using OEM ECU, keep knocking on the door of your Ford service department !!!

Cheers

Robin.