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1994 B250 engine light on after warmup & running rough

05-30-2011, 02:48 PM
Don't know where to go now. Have a 1994 B250 318, auto. Started runnning rough and guzzling gas on me. When I start it up in the morning, it runs fine for the warm up. once it comes up to temp, it starts running aweful. Runs rough, stalls after a while, goes through gas like no tomorrow. If I turn the key off and back on it runs normal for 10 mins again, then goes right back to old problem. We have checked the codes and am pulling up all kinds of things from O2 sensor, which we replaced, to EGR, fuel pump codes, also replaced (pump), and power loss to pcm. cleaned connection to PCM, replaced throttle postion sensor, map, and air temp sensor and engine temp sensor. don't know what else to try at this point. Any ideas??? NEED HELP!! Even our mechanic isn't sure what to try...

05-30-2011, 08:00 PM
Sounds like your injectors are leaking and causing a rich mixture condition. This is okay when the engine is cold since the engine requires a rich mixture then.

05-31-2011, 07:44 AM
Is there any way to test for this? Or do we have to just replace the injectors?
We suspect it is not the injectors because sometimes it will run fone, then other times it starts dumping fuel like crazy and you can hear on top of throttle body you can hear the injector open out of no where.

05-31-2011, 05:22 PM
Your 3 options are:

1. a faulty injector.
2. an intermittent short in the injector wiring.
3. a bad ECM.

Take your pick.

06-05-2011, 12:57 AM
When the O2 sensors were replaced, are they the Bosch brand? If so, then you have found your problem.

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