I’ve noticed that my 1977 has a nasty habit of stalling at idle, while in gear (R or D) with the steering wheel turned to an extreme left or right.
When not in gear, it dips a little, then is fine.
it does so when the engine is cold or hot.
The idle speed is set at 750 RPM as per the emissions sticker and doesn’t wander the least. Though it is a bit shaky at idle.
I’m just not sure what’s going on or if these engines are just easily overloaded in the idle loop.
Additionally, and possibly a separate issue is that it seems to run lean at idle, I get a little backfiring and the smell is definitive.
Does anyone have any ideas?
Also- I’m curious if anyone near me has experience with these engines and what’s normal for them. the car wasn’t even running with I got it and I’ve never seen another Pre HE V12 run so I just don’t have a point of reference for this car. Located near Montclair, NJ
Zack
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
2
I’m betting the stalling and the lean run are related.
I can’t offer too much help, but I will note that the D Jetronic has a known issue with the MAP sensor getting a crack in the diaphragm or something, leading to bad MAP readings which in turn lead to bad mixtures. IIRC, the quickie test is to disconnect the MAP sensor and check to see if the MAP sensor itself will hold a vacuum. If it leaks, it’s probably gone bad.
Thanks for the tip. I checked it out and the MAP sensor seems to hold vacuum just fine. ~10"Hg for 10 minutes with no drop, (taken at the Tee in the center of the engine)
I’ll try and find some values for the sensor’s output at vacuum and check it’s correct to start.