Engine Stalling - AJ16

[ng4xjs]

Dear All

Your thoughts plrase. Over the last 12 months or so my car has also taken it upon itself to stall intermittently, but always restarted first time. So I've been working my way through methodically, but still have the problem. Like others,immediate thought was to replace the crankshaft position sensor and yes for the fist month perfect. Then when it failed again my choice was to replace the fuel filter but to no avail, still occasionally stalls.

I'm getting a DTC P1177 which according to TB 18 -53 suggests the cause to be a rich fuelling trim so I'm now looking for air leaks on the intake side. I was going to clean as may electrical connectors in the chain with a good dose of contact cleaner, see what happens. I'm nor sure but maybe others can equate this code to a stall scenario. I also have a cracked converter, usual seam which I had welded back but maybe still a slight leak. Would this cause the problem? When I had the car MOT'd at the end of March the Examiner said he had to run the engine at high revs to get the O2 sensors to kick in. Do I need 4 of these? Also. Mine is Japanese spec so that there are also temp sensors, one on each pipe. Mine can stall both cold and hot so I'm guessing not.

The only other two observations I have is that the problem usually presents following a period of increased use of the throttle. I also know that the spark plug rubber seals under the cam-cover need replacing. One had an excess build up of oil. Is it possible that this is shorting the plug and sending out a bad signal?

Any thoughts ideas greatly received. In particular the relationship between P1177 and a stall.
Many thanks
Nick

[cafcpete]

Don’t know about stalling, but my book says P1177 is lean not rich and points to maybe fuel surply issues. Easy to change the fuel filter first, and clean the MAF.

[ng4xjs]

Thanks - Most odd as Technical Bulletin 18 -53 definitely suggests the cause to be a rich fuelling trim. If I could work out how to insert an image I would give it a go.
Nick