mixture control solenoid wont cycle
10-19-2010, 08:09 PM
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mixture control solenoid wont cycle
im trying to get my cart to pass inspection (NJ) so i decided id have to put the old q-jet back on. the problem is i have cut most the wires to the ecm because i didnt really need the ecm after my rebuild. but now i do. i used schematics and got my 02 sensor and 02 sensor ground wired. along with the tps, mcs, and the two engine ground wires from ecm. the problem is i have voltage present at the mcs, and when i run a jumper wire to ground for it. it will click. but when wired to the ecm it will not. the solenoid has 25 ohms of resistance and specs call for atleast 10 ohms. any ideas? must i wire every part for the ecm? if so im beat because i pulled mostly everything off during the rebuild.
10-19-2010, 08:58 PM
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Re: mixture control solenoid wont cycle
Computer control is all-or-nothing.
10-19-2010, 10:09 PM
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Re: mixture control solenoid wont cycle
i believe that is true to a point. i just watched a gm training video on the c3 ecm system. it says that the input sensors for the fuel delivery system are the baro sensor, manifold absolute pressure (MAP) sensor, throttle positioning sensor, oxygen sensor, temperature sensor, vehicle speed sensor, and tach signal or engine load. and that is all processed to determines the operation of the mixture control solenoid at 10 times per second. so i figure if i can wire those sensors in, the ecm should be able to process the information and send it to the mcs. hopefully it works. im just hoping the vehicle speed sensor still works. i never messed with it but removed an after-market alarm that was wired like a rat nest under the dash before i bought it.
10-20-2010, 03:07 AM
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10-20-2010, 06:56 AM
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Re: mixture control solenoid wont cycle
Voltage at the MCS does not mean the ECM has power. The power lead to the ECM is the single wire coming off of the positive battery terminal running near the fuel lines.
The computer switches the ground to the MCS. The MCS is powered off of the engine controls fuse under the dash.
The ECM will work without the EGR or AIR systems hooked up. It will also not know if the bump solenoid or TCC lockup is connected.
There should only be ONE wire to the O2. It grounds through the mechanical connection.
The computer switches the ground to the MCS. The MCS is powered off of the engine controls fuse under the dash.
The ECM will work without the EGR or AIR systems hooked up. It will also not know if the bump solenoid or TCC lockup is connected.
There should only be ONE wire to the O2. It grounds through the mechanical connection.
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