QuestionMy wifes 1991 240 (148K miles) will not run. After doing some shopping she started the car, ran rough, and stalled. The only way it would run is at higher rpm. As soon as you let up on the gas it would die. It acked like it was running rich and the plugs were fouled out. Change the plugs (they looked fouled) but this did not help the problem.
I pulled the codes and got 1-2-1(fault in the signal for the air mass meter, 2-3-1, and 2-2-1 ( both deal will rich and lean conditions at cruise), with the check engine light also on.
Had some one tell me to the vacuum tube from the regulator (on the injector log) and if i smelled gas, then the diaphram had a hole in it. I did check it with a vacuum pump and it held vacuum pressure.
Other things I checked are fuel pump. I take it that once pressure has built up that it cuts out. It would only run for 1-2 sec ( or not at all) and then stop. It would run continueously when I jumpered between fuses 4 and 6. I tried starting the engine while jumpered but nothing changed.
I want to check the fuel pressure next but can not break the connection loose on the injector manifold and not sure I have the proper adapter to T off this so I can install my gauge.
AnswerYour symptoms and codes both point to a bad air mass meter. To verify , clear the codes and try starting the car again and see if the codes come back.
Sounds like your fuel system is ok, you're getting fuel and the fuel pressure regulator is holding pressure.
Try disconnecting the air mass meter connector and see if it starts better or idles better, if there is a change, this usually means a bad air mass meter. If this is so, be sure to also replace the air cleaner temperature sensor, a brass thermostatic element in the air cleaner housing. This is the thing that usually causes the air mass to go bad.
