still no start

09-16-2011, 04:09 PM
just replaced fuel pump on a 95 jimmy 248550mi, 4.3 . it started right up and took ride but then it died , if shut off engine it would start fine but when in drive it looses power and pressure with fuel tester, fuses look good, relay clicks but still nothing. any advice to where to start looking . could it be electrical, computer ,thought might be cat at first but dont know where to start looking .the fuel pump is what thought was my original problem .

09-16-2011, 04:48 PM
Was it a name brand (delco) fuel pump? Have you replaced the fuel filter?

09-16-2011, 06:16 PM
yes an ac delco

09-16-2011, 06:45 PM
Better start from scratch.... just because the pump is new, doesn't mean it's good. Or it could be there are other problems.

Key ON, engine OFF, fuel pump running, pressure must be 55psi to 61psi and must remain above 50psi for 3 to 5 minutes after the pump shuts off.

09-17-2011, 04:04 PM
im gona take for now that the pump is good ,as this is exactly same original symtom.. poss a bad wire some where. would it be wise to tap into power wire near pump then energize it. as to see if there is a break in wire

09-17-2011, 07:27 PM
Best to apply battery voltage and ground directly to the pump module, totally bypassing the connector. The grey wire is battery feed and the black wire is ground. The original module connector was a poor design: High resistance would create heat and melt the plastic, deform the connector, and eventually lose contact completely. Most replacement fuel pump modules come with the new style connector and it needs to be soldered to the vehicle harness.

09-18-2011, 07:17 AM
should i unplug connector then add voltage,what about purple wire or does that just go the fuel gauge.

09-18-2011, 10:03 AM
have three wire connector .put power to gray and ground to black but nothing to purple and got no sound , do i need to connect purple to anything..

09-18-2011, 11:46 AM
Purple and the orange wires are for the feul level sensor. The 3 wire connector is for the fuel tank pressure sensor.

Unplug the module connector. With battery voltage applied to the grey and ground applied to the black wire terminals in the module, the pump must run. If not, it's bad.

09-20-2011, 05:41 AM
got pump out and it tested no good (frozen). thanks for everything k

09-20-2011, 12:07 PM
Good job, thanks for posting back.

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