ENGINE STALL

[Anonymous]

HI WONDERING IF ANYONE CAN HELP ?, GENERALY MY XF EFI RUNS O'K', BUT SOMETIMES (HOT MAINLY), ON VERY LIGHT THROTLE WHILE MOVING, THE ENGINE STUMBLES OR STALLS IF YOU DONT GIVE THE THROTLE A BLIP. I BELIEVE IT HAS LOW AND A HIGH PRESSURE FULL PUMPS, COULD THE LOW PRESSURE PUMP HAVE SOME DIRT IN IT ?, OR DOE YOUS RECKON IT SOMETHING ELSE/ .....................THANKS

 

[Anonymous]

ab,
Usually with the EFI system on the XF vacuum leaks are the cause of low speed running problems.
But it always requires a detailed look at the engine.
Make sure the tune up is spot on the specs. Good plugs and the rest of the ignition system is good.
Check the EGR valve. This is the valve at the rear of the throttle body.
This is used to direct exhaust back into the engine. Usually there is a vacum leak at the shaft.
Spray with a penetrating spray, (CRC/WD40) if it affects the idle . Fix that and try the operation.
Noel.

 

[Anonymous]

thanks for the tip ! I think you are right it only happens when its warmed up, i tried spraying the shaft - no differance

 

[Anonymous]

Next in the procedure.
How old are the simple and cheap things?
Spark plugs, leads, coil distributor cap and rotor, look at all that stuff too.
Look all over the engine for leaks.
Make sure that big donkey dick tubing is properly attached and not leaking anywhere.
Look at the vacuum hosing, all of it. Is it in the right place and still all attached to the correct areas.
Has it got the correct dipstick?
The last thing I can think of is the fuel injectors being a bit gummy or fuel pressure problems caused by many different things.This causes reduced flow at low engine speeds.
Hope this helps.
Noel.

 

[yeah right]

This problem is so common. I have exactly the same thing - crap idle - but it's ok at speed. I've tried to get to the bottom of it - now I'm going to remove every single vacuum line from the intake & plug the plenum ports & put them back on one by one to see if I can find it. It's not the EGR - I've already blanked that off. I have a suspicion about the brake booster now - but we'll see when I block that puppy off. These EFI's are a pain in the ass.

My Subaru is EFI & has never had a problem of any kind - and it's only 2 years newer with 100k's more - perfect idle 100% of the time - hot or cold - anytime.