1988 Chevy Blazer fuel injection

1988 CHEVROLET BLAZER
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TRIGGER999
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Electrical problem
1988 Chevy Blazer 6 cyl Two Wheel Drive Automatic

t .b.i injection i am getting no ground pulse i have replaced the ecm and the distributer and still no ground pulse have checked all fuses and fuseable links i have power at injectors but no pulse when cranking? ido have spark
Nov 30, 2009 at 12:46 PM
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RASMATAZ
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When the key is first turned ON, without the engine running, the ECM will turn the fuel pump relay ON for two seconds. This builds up the fuel pressure to normal operating pressure. If the engine is not started within two seconds, the ECM will shut the fuel pump OFF and wait until ignition reference pulses are present. As soon as the engine is cranked, the ECM turns the relay ON, which powers the fuel pump. The ECM continues to power the fuel pump during engine operation. If the fuel pump relay fails, it is backed up by the oil pressure switch, which continues to operate the fuel pump as long as oil pressure remains above 28.0 kPa (4 psi).



A faulty fuel pump relay can result in long cranking times, particularly if the engine is cold.
An inoperative fuel pump would cause a no start condition. A fuel pump which does not provide enough pressure can result in poor performance.
Nov 30, 2009 at 12:57 PM
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