Repair

Every year gets new oil & oil filter. Only has 73,340 miles. Within the last month, new air filter, new water pump, new plug wires, new thermostat, and ran fine for weeks after all that. Then while driving, it was like you turned the key off, then on, made it to the garage. Where now all the engine will do is start, run smooth for 2 - 3 seconds then nothing. How do you check for "mil" codes and what else could possibly be done to "tune" it up. Someone said that it was the fuel pumpj. I replaced it. Same results. If it is a sensor of sorts. Which one and how do you "test" the sensor to see if it good or not?

I used a GM code reader (should jump the terminals) and the only code flashed was a 12. Which according to the manual "no distributor signal to ECM" system PASS. Is there a break in the wire loom? I took the Module that is attached to the coil packs to AutoZone where they put it on their tester and said was good. I watched as he did test and all green lights showed for the test. So now what do I do with the code 12?

The new pump activates for a few seconds each time you turn the ignition on. But no not much pressure and with the key on the pressure goes to near zero.

In the past years at first start sometimes the engine would faultier for a moment then recover during the shift from park to Drive/reverse then keep running fine. Now today with the pressure at near zero and no voltage to pump after engine stalls. What could the problem be. What/where is the relay to keep the fuel pump running?

Thank you JDL for the graphics. Can you make it larger?

First I'd like to say thank you. And I have looked all over the internet to see if I could find that diagram. Because I cannot read it. Too fuzzy. But I think the problem lies in the fuel pump RELAY. The fuse must be good or it would not run the pump with ign key on. So the pump does run, the engine does start for a sec. I believe that the relay is not working correctly. I would check the voltage ((as in your last post)) but you will have to lead this blind dog to the exact location of the RELAY and if there is a separate "fuse" for when the engine is "running". It looks to me that the "fuel pump RELAY" is on the engine side of the firewall & closest to the steering column. Correct? I have attached a photo of what looks like 4 relays on center of firewall are one of these the pump relay? ((And one of the engine area))

Well, the best thing is I sold it to a backyard mechanic that replaced the timing sensor down on the crankshaft. It still ran rough BUT better then before AND kept running and did not die. Later he replaced the injectors, then it ran smooth and strong again. So that anyone reading this can have the ANSWER TO THE PROBLEM THAT WAS ONCE INQUIRED ABOUT HERE.