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Discussion Starter #1
Hi guys, I have a 1993 GMC jimmy that wont start. New fuel pump, new fuel filter, new cap and rotor, sparkplugs, coil pack, and new cpi spider injector. I honestly don't know what else it could be. I'm getting spark, and my fuel pressure is great, I also checked all the fuses under the dash, they were all good. Can someone please help me figure this out? Thanks in advance.
 

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Discussion Starter #2
me and a buddy of mine poured gas into the intake and it ran until the gas ran out
 

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B4U Task Force Admin
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What engine? What was the fuel pressure?
 

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98 2.2 Extended cab, 2001 V6 Extended cab Sport Suspension, 2001 V6 Extended Cab 4x4
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May sound like a stupid question but sometimes those are the ones that kick out collective butts more than anything. Is the spider plugged in? IF so are all the ECM fuses good?
 

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10+ 1st Gen 4.3's
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Disconnect the TPS connector, and see if it starts. If = YES, the black ground wire at the TPS may not be making good connection, and this bad ground will make the ECM think the throttle is wide open, enter Clear Flood Mode where no fuel is delivered from the spider. It won't start.

Ask me how I know about this one.............. It kicked my *** for about two hours before I figured it out. Just a bad connection, I didn't replace anything.
 

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10+ 1st Gen 4.3's
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If it doesn't start?
I assume you don't have a scan tool where you can watch for Injection Pulse Width IPW. A CPI during cranking is about 2.1-2.4 IPW. If it is not in this range, it won't start.

With the key in RUN, check the pink/blk wire (car side) at the 2-pin connector by by the alternator that becomes the red and blue wires that go into the plenum and to the injector for +12Volts. If no power, check the ECM 1 fuse. With the connector connected, insert a straightened paper clip into the seal from the wire-side of the dk blue (car side) wire. With the key in RUN, short the wire to ground for about 3-4 seconds. Attempt to start. If it fires, the injector circuit is intact, and delivering fuel.

Because it will fire with a "prime", the ignition system is intact. But the ECM may not be receiving reference pulses. Be sure the 4-pin connector is secure in the rear of the distributor. If = YES, here is a simple test for "reference pulses". Without reference pulses, there is no injection.

Turn key to RUN, but do not crank. Fuel pump will run for 2 seconds and stop. If = YES,
Turn key to CRANK for just enough to turn the engine perhaps a turn or so, and return the key to RUN.
Listen for the fuel pump to be running, then stop.
If the pump DID run again when cranked, reference pulses were received by the ECM.
If the pump did NOT run again, re-run the test to be sure, and if same result, reference pulses were not received. Because you have spark (engine runs with a primer), the only cause would be the Ignition Control Module in the distributor. In many, many "good crank, no starts" I have had exactly ONE ICM fail in this manner. It is a very unusual failure mode. But I have had it happen to me. Once.

Be sure the 4-pin is plugged into the rear of the distributor.
 

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Discussion Starter #12
I did check to see if the cpi injector was getting power and it was getting about 12 volts
 
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