truck starts,runs,then dies

boxerbilly · August 16, 2014

I have a 98 k 1500, fuel pump went bad, replaced it. 60 psi on rail,cranks, runs, dies. Test relay, it good. Replace filter and then pressure regulator. Starts, runs, dies.I'm at a loss. I've tried the passlock trick with no success. Security light stays on, never goes out. No engine light, shows oil pressure before it dies. All fuses good. Its aggravating. Starts, runs for a second or two then dies. Moneys tight or I would take it in. Please help.

Danthaman69 · August 16, 2014

Sounds like the computer.

1997SierraSLT · August 17, 2014

when you say "pressure regulator", are you referring to fuel pressure regulator mounted to the side of CSFI fuel injector cluster under the upper intake plastic manifold? If so, that is a big job which involves disconnecting multiple electrical wiring harnesses and vacuum lines. Is it possible one of these was not re-connected? Thinking it could be electrical or massive vacuum leak.

Did the truck run fine before the fuel pump was replaced? If so, check to confirm fuel line hoses to fuel pump are not pinched or kinked. You may have pressure at the fuel rail, but lack of fuel flow.

oldscsc · August 17, 2014

Was the truck running fine with the security light on beforehand?

8.1HD/ALLISON · August 17, 2014

Security light on. Check codes and diagnose.

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boxerbilly · August 18, 2014

Narrowed down to theft deterrent module, can you do the resistor trick to this or do you have to replace it.

Duelin · August 18, 2014

To start off with does your key have a resistor chip on the key? The resistor trick is used to bypass the contact in the steering column. If you have narrowed down to the module then it wouldn't make any difference. The module would be receiving the same values. Either from the keys or from the resistor pack. Now if you have a resistor chip on your key and the contacts in the column are gone then yes the resistor pack would work.