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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
Now that I've gotten my USB ALDL cable, and TunerPro running on my tablet, I can begin tracking down some issues with the engine.
I keep getting the Code 44, lean O2, despite having replaced the O2 sensor with a new AC/Delco O2 sensor. BLM's are running around 150 at idle, and even during cruise, they generally stay in the 150's, with an occasional drop into the 140's.
I'm assuming I'm looking for either a vacuum leak in the manifold/plenum/vacuum lines, or a possible bad injector. It "hunts" between 450-1050 RPM when cold, and settles to 750 while warm, with an occasional sudden drop and stumble if sitting at a light for a long time. Idle is steady except for the occasional stumble, and idle quality has a slight miss noticed, which seems to disappear when underway.
PO has removed and blocked off the EGR, and removed the vacuum source to the evaporative purge solenoid.
Now that I've gotten my USB ALDL cable, and TunerPro running on my tablet, I can begin tracking down some issues with the engine.
I keep getting the Code 44, lean O2, despite having replaced the O2 sensor with a new AC/Delco O2 sensor. BLM's are running around 150 at idle, and even during cruise, they generally stay in the 150's, with an occasional drop into the 140's.
I'm assuming I'm looking for either a vacuum leak in the manifold/plenum/vacuum lines, or a possible bad injector. It "hunts" between 450-1050 RPM when cold, and settles to 750 while warm, with an occasional sudden drop and stumble if sitting at a light for a long time. Idle is steady except for the occasional stumble, and idle quality has a slight miss noticed, which seems to disappear when underway.
PO has removed and blocked off the EGR, and removed the vacuum source to the evaporative purge solenoid.
Lastly, what is this thing? It's an '88 5.7 TPI.
What is this?
The rectangular device barely hanging onto the bracket, with green wires.
High BLMs means the ECM is trying to add MORE fuel than what is called for in the base fueling maps. 128 is "dead on", lower it's trying to lean the mix, higher and it's trying to richen it. I think the "lid" is 150 maximum (could be 160- to be honest, I forget), at which point it starts throwing lean O2 sensor codes.
It's also possible the injectors are not the size you think they are. Had this issue years back when we put in "30#" SVO injectors we bought off eBay. BLMs always at or near the roof. Ran the numbers on the injectors and they turned out to only be 24#. Oops. Put in the correct sized injectors and everything was kosher again.
12-15-2015, 07:30 AM
