why wont my blazer start
I have a 2000 and it will not start. i have changed the distributor the rotor butten the cap the wires and plugs camshaft sensor the cranckshaft senor the MAF and i have plenty of fuel in it. any suggestions?
i have been having problems for a few months and some things were changed for maintance others were because of the codes. i do not smell fuel from intake.. one code i have now is p0420 annd i think another one was p0120,
P0120 - Throttle Position [TP] Sensor Circuit
P0420 - Catalyst System Efficiency Below Threshold (Bank 1)
I would handle the throttle position code first. Check out the other TPS codes in the OBDII Code Index link in my signature for a wiring diagram and check out the wires as well as do a functional test on the TPS sensor. By back probing the sensor return wire with the ignition on, you should see ~0.5V at idle and ~4.5V at wide open throttle. The reference line should have +5V and there should be a ground. If either of these two are missing, the TPS sensor will not be feeding the proper information to the PCM.
You can also run down through the P0420 link I provided and see if anything jumps out at you.
But I would definitely test the fuel pressure. Fuel pressure problems are well known with these trucks.
P0420 - Catalyst System Efficiency Below Threshold (Bank 1)
I would handle the throttle position code first. Check out the other TPS codes in the OBDII Code Index link in my signature for a wiring diagram and check out the wires as well as do a functional test on the TPS sensor. By back probing the sensor return wire with the ignition on, you should see ~0.5V at idle and ~4.5V at wide open throttle. The reference line should have +5V and there should be a ground. If either of these two are missing, the TPS sensor will not be feeding the proper information to the PCM.
You can also run down through the P0420 link I provided and see if anything jumps out at you.
But I would definitely test the fuel pressure. Fuel pressure problems are well known with these trucks.
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JimmyBlaze541
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