SL/R129: 1996 sl500 stall at 1500rpm
Thread Starter
Newbie
Joined: Jul 2019
Posts: 1
Likes: 0
1996 sl500
1996 sl500 stall at 1500rpm
I'm at my whits end. I did a motor swap and it ran fine until I floored it one time. Now it stalls out between 1500 and 2000 rpm. Idles fine. I am guessing this is limp mode. Any suggestions would be greatly appreciated. I swapped out the throttle body with my old engine thinking it might be bad
Banned
Joined: Jan 2006
Posts: 1,982
Likes: 393
From: Atlanta, unfortunately
'09 S600, (2) R129 300SLs, '03 SL500, '03 SL55
It is not limp mode.
I presume that somehow you are losing spark at increased RPM, or with opening the throttle additional fuel is not added and the mixture is too lean to burn. It's intuitive that a faulty air-mass sensor could cause a lean mixture, but I think your engine can run with no sensor at all, albeit poorly, perhaps.
I would search the "Tech Help" forum of peachparts.com and look for a thread discussing a problem similar to yours. Years ago there were no fewer than four professional Mercedes technicians contributing there on a regular basis: stevebfl, mbdoc, Gilly, and Benzmac.
I presume that somehow you are losing spark at increased RPM, or with opening the throttle additional fuel is not added and the mixture is too lean to burn. It's intuitive that a faulty air-mass sensor could cause a lean mixture, but I think your engine can run with no sensor at all, albeit poorly, perhaps.
I would search the "Tech Help" forum of peachparts.com and look for a thread discussing a problem similar to yours. Years ago there were no fewer than four professional Mercedes technicians contributing there on a regular basis: stevebfl, mbdoc, Gilly, and Benzmac.
