Engine stalling

[Jabbah]

Had an odd problem on the way back from Le Mans. Engine was fine starting off and on a long run but when coming to a stop at a toll or roundabout the revs would die and unless I was quick with the throttle would stall. Tried turning everything off and on again which seemed to fix it until after the next long run and then the same thing happened again. Any ideas? One of the coil packs might need changing as I had problems in that area over the new year. Maybe lambda sensor related going between closed and open loop?

[a1rak]

Have you tried adjusting the idle screw. The linkage and inlets all move when the engine gets hot so I would do that before getting to bogged down.

[andrewlloyd]

Had the same problem ended up being the lamba sensors

[jsfstu]

Same here Lamba at fault keep a spare you will get through them

[gruffalo]

My money would be Lambda sensors, I must have put 10 in my car over the last 40K miles.

[Jabbah]

I'll connect up the laptop next time I take her out and see if there is anything flagged up.

Are the lambda sensors easy to change?

[N7GTX]

On the 4.2 I remove the cats and this gives lots of room to unscrew the sensors. Remove the scuttle panel and you can reach the connectors. I also remove the throttle rod just in case I damage it.

[Jabbah]

The symptoms in this throttle pot thread seem to match mine pretty closely:

http://www.pistonheads.com/gassing/topic.asp?t=132...

"erratic tickover, poor starting, cutting out when slowing down."

What's the best way to check the TPs? Connect up a laptop and look at the readouts?

[N7GTX]

Yes, its the only accurate way to set them up. In the Help menu in the software are all the details you need to do this and the procedure.
If you find you cannot get enough movement on the throttle bodies to get the correct readings then you can drill out the fixing holes on the throttle pots with up to a 7mm drill. Make sure you have suitable washers on the fixing screws!

[Mags]

Check the idle screw first. Mine was setup by Andy at APM and was perfect, by the time I got home it was stalling and a nightmare. Turns out the idle screw had come loose and backed itself off. Simple fix and now she idle's and runs perfectly.

[TheRainMaker]

gruffalo said:

My money would be Lambda sensors, I must have put 10 in my car over the last 40K miles.

Wow, you sure you don't have an under lying problem?

I've replaced two over a slightly higher mileage.

[gruffalo]

no, rest of the car is fine and healthy, engine map was penty safe enough so not burning them due to a weak mixture, they just kept failing, now turned off in software and replaced with bolts.