'94 Z issues....help!
#1
'94 Z issues....help!
Greetings! I've been digging through here for a couple of days and not finding what I'm looking for, so if the answer is in another thread or sticky, please forgive.
OK. 94Z, 6 speed, 155K. In the last 8 months, I have replaced: optispark (with vacuum hose upgrade), plugs, wires, coil, ignition module, EGR valve, vacuum line kit (quadruple checked), air pump, all coolant temperature sensors, and all O2 sensors are within 2 years old. The problem I'm having is at low RPM above 59 degrees, the car stumbles and loses power until around 2,000 RPM. The car runs fine with lots of power when below 59 degrees. Am going to be trying to pull the data stream when I get a silly battery for my scanner, but am at a loss as to what could be causing the problem. Does anybody know of any sensor outside of the air pump that activates after 59 degrees? I am also curious if I could be having computer problems since I've had to install a fan override switch because the computer will not turn on the fans for some reason. Any help would be GREATLY appreciated!
OK. 94Z, 6 speed, 155K. In the last 8 months, I have replaced: optispark (with vacuum hose upgrade), plugs, wires, coil, ignition module, EGR valve, vacuum line kit (quadruple checked), air pump, all coolant temperature sensors, and all O2 sensors are within 2 years old. The problem I'm having is at low RPM above 59 degrees, the car stumbles and loses power until around 2,000 RPM. The car runs fine with lots of power when below 59 degrees. Am going to be trying to pull the data stream when I get a silly battery for my scanner, but am at a loss as to what could be causing the problem. Does anybody know of any sensor outside of the air pump that activates after 59 degrees? I am also curious if I could be having computer problems since I've had to install a fan override switch because the computer will not turn on the fans for some reason. Any help would be GREATLY appreciated!
#2
I'm assuming the car runs like crap when it goes into closed loop? Unplug the MAF sensor and try driving it around in open loop. It sounds like an EFI problem from faulty sensors. Is it throwing any codes?
#3
test your coolant temp sensor and intake air temp sensor. number 20 on the list here 4th Gen LT1 F-Body Tech Aids
#5
Well, unplugged the MAF sensor as per your suggestion, and started the car from cold. the MIL lit up, fans came on, and was stumbling from the first second, and stayed that way till it reached thermostat temp. I let the car cool, plugged the MAF back in and started the car, and again from cold, ran great till aprox. 60deg. where the misfire began.
I watched the data stream while it warmed up, and didn't see anything change radically when the temp came up, but, honestly, I really don't know what to monitor, or what the values should be to begin with. I'm stumped...
I watched the data stream while it warmed up, and didn't see anything change radically when the temp came up, but, honestly, I really don't know what to monitor, or what the values should be to begin with. I'm stumped...
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