Mechanics

CHEVY NO FUEL OR SPARK

1993 Chevrolet Blazer

Electrical problem
1993 Chevy Blazer V8 Four Wheel Drive Automatic 210000 miles

Hi been working on my 93 chevy blazer just quit on me have no sprak or fuel changed coil and pick up coil. Still will not start but if I leave it over night then try to start it next day it will start runs great then stalls. May start again but after it stalls out again nothing not spark or fuel. It does have auto start not sure if that has anything to do with i. Hope you can help thanks.
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Durek420
September 5, 2009.




Possible Causes & Corrections:  Ensure hot air tube is connected to air cleaner.  Check thermostatic air cleaner for proper operation.  Check Idle Air Control (IAC) system for proper operation.  Check PCV valve for proper operation.  Unplug MAP sensor. ECM substitutes a default value for sensor signal. If stall condition is eliminated, replace sensor.  Check EGR system for proper operation.  If stall occurs when air conditioner is turned on, check for air conditioner clutch signal to ECM terminal. Voltage at A/C terminal of ECM should be battery voltage when air conditioner compressor clutch is engaged. A high voltage surge due to a shorted compressor clutch diode could cause ECM shutdown.  Check for an overcharged A/C system.  Check for plugged or restricted fuel lines.  If engine starts but then immediately stalls, open distributor by-pass circuit. If engine now starts and runs okay, replace distributor pick-up coil.  Using Spark Tester (ST-125), check for a weak spark from ignition coil.
Check crank sensor for signal when it wont start. Also was/is service engine soon light on? Read like this. Cross these two terminals as shown with a piec of wire, then turn the key on. Count the flashes, a 22 will flash as 2 flashes then a short pause, then 2 flashes, if more than one code is stored, the pause will be longer. The codes will display three times and end with 12. Write them down and post here. This connector is right under the middle of the dash...


http://www.2carpros.com/forum/automotive_pictures/62217_Pre95GM1_3.jpg


Merlin2021
Sep 5, 2009.
The codes I got are 22 and 34 thanks for the help bro. Hope these are the reasons

Tiny
Durek420
Sep 7, 2009.


http://www.2carpros.com/forum/automotive_pictures/62217_22_1.jpg



http://www.2carpros.com/forum/automotive_pictures/62217_34_2.jpg


Try unplugging the MAF and see if it runs. Usually this is the TPS, replace that first. THROTTLE POSITION (TP) SENSOR 1. Install jumper wires to enable connection of a DVOM in parallel between TP sensor harness connectors. Connect DVOM positive lead to Dark Blue wire terminal. Connect negative lead to Black wire terminal. See Fig. 3 . 2. Turn ignition on, engine off. Signal voltage should gradually change from less than one volt at closed throttle to about 5.0 volts at wide open throttle position. If reading is not as specified, replace TP sensor. 3. TP sensor circuit malfunction should set a related trouble code. For further information, see appropriate TESTS W/CODES article in this section. Also see TPS ADJUSTMENT in ADJUSTMENTS article in this section.


http://www.2carpros.com/forum/automotive_pictures/62217_TPSGM_1.jpg


MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR 1. MAP sensor circuit malfunction should set a related code in ECM memory. See Fig. 1 . If a code is present, see appropriate TESTS W/CODES article in this section. An out-of-calibration sensor may not set a trouble code. Use following procedure to test sensor calibration. If driveability problems exist, MAP sensor failure is suspected and no MAP code is present, disconnect MAP sensor connector. If driveability condition improves, check MAP vacuum hose for splits, kinks, proper routing and blockage. If no problems are found, replace MAP sensor. 2. With ignition on and engine off, check MAP sensor parameter using a scan tester connected to Data Link Connector (DLC). Voltage should be as specified in MAP SENSOR VOLTAGE RANGE table. 3. If MAP sensor voltage is as specified, go to next step. If voltage is not as specified, check for 5-volt reference supplied to sensor. Check harness integrity. If no problems are evident, replace MAP sensor. 4. Using a hand-held vacuum pump, apply 10 in. Hg to MAP sensor and note voltage change. Voltage should drop to about 1.0-2.5 volts less than specified in table. If voltage is not as specified or voltage reading does not immediately follow vacuum change, MAP sensor is faulty.


http://www.2carpros.com/forum/automotive_pictures/62217_34a_1.jpg

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Merlin2021
Sep 8, 2009.
Those would make not have sprak anf fuel

Tiny
Durek420
Sep 8, 2009.
Not usually a spark, but could be a fuel problem. Did you check all fuses marked IGN? Under the hood fuse box? And what does the security light on the dash do 1.) Before you insert key? 2.)After you turn ignition to just ON position? And then crank?

Merlin2021
Sep 10, 2009.

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