QuestionThe 6 oor 7 times i tried this it started every time. I turn turn the key forward for two seconds or so at a time about 2 times and it starts right up. I hope that this narrows down a possible solution. Again, thanks for your help.
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Followup To
Question -
Sorry I could not get back to you sooner. I did hear the fuel pump turn on for roughly 2 seconds when I had somebody turn the key one click forward. I took the truck on a 400 mile trip to chicago towing a trailer. it ran great. After I got down there it started with out no spray all week. Even after I got back home it started even after the truck sat for 2 days. This was a week ago. Now this week it is back to doing the same thing were you need to spray to get it started. Maybe it is after you told me to check the fuel pump that it seems that the fuel pump is a bit loud at times. Is this normal? I still have 60 PSI at start up and while running. Is it possible that the injectors are going bad? What should they OHM out at? I just put a small squirt of starting fluid in and it fires right up and it does not skip a beat. I only have to do this if it sits for longer than 2-3 hours. Any additional ideas or comments? Thanks for you help.-------------------------
Followup To
Question -
I have a 1997 Chevy Tahoe with the 5.7 Vortec motor with 118,000 miles on it. It has the SFI set up I believe. It will not start when it has sat a while, say 3 hours after running. I have to spray a small amount of starting fluid by the throttle body to get it to fire. Once it gets started it runs great. I had this issue for about a month then the service light came on. The code for #7 misfire came up. So upon further troubleshooting I found that the #7 injectors was bad. It had over 12 ohms of resistence. So I replaced the #7 injector and the pressure valve on the injector body. After that the service light did not come back on and it ran good. I still had the issue with it not starting after it sits. I checked the fuel pressure and it is about 58 lbs before start up and while running. I replaced the fuel pump reley (since it was an inexpensive part), cap and rotor, and the fuel filter. I still have no luck starting in the morning with out starting fluid. I figure the fuel pump is good with that kind of pressure. The wires appear to be in great shape, replaced them last fall with NAPA lifetime wires. At that time I replaced the plugs with Bosch Platnuim plugs and they all look good. It cranks over fine with plenty of juice. The air filter looks clean and the indicator by the MAP sensor is green. I am runnning out of ideas and hope you can help me out. I also hope I gave you enough information. If you need more please ask.
Thanks,
Tony Peterson
Answer -
Fuel pump test:
1. Get yourself a helper.
2. remove the gas cap.
3. have one person listen in the gas tank at the gas cap opening.
4. have the other person turn the ignition switch to the ON position ONLY so as the dash lights come on. Do NOT attempt to start the engine.
5. As soon as the ignition key is turned to the ON position, The person at the gas tank should hear the fuel pump run for TWO SECONDS and then it should STOP.
6. Does it ?.
If you do NOT hear it run, in most cases the fault is the fuel pump.
As soon as you turn ON the ignition switch to start the engine a 2 second ONLY battery voltage signal is sent from the computer to the fuel pump relay and from the relay back to the fuel pump in the fuel tank. This runs the fuel pump for ONLY 2 seconds of which pressurizes the fuel system in preparation to start the engine.
Once the engine starts, The computer BYPASSES the fuel pump relay and sends constant contionous battery voltage from the computer to the oil pressure switch of which is now CLOSED because the oil pressure is UP because the engine is running. Therefore the battery voltage flows thru the oil pressure switch back to the fuel pump to run the fuel pump constantly until you turn OFF the engine.
let me know.
autohelp
Answer -
Try cycling the ignition key several times so as to make the fuel pump run each time and then try and start the engine and see what happens.
AnswerImagine your fuel pump as your kitchen sink.
You attach a pressure gage to the pipe and it reads the proper pressure.
However if you only turn ON the kitchen sink so as to only get a small stream of water coming out of the faucet, Think what this would do to your starting the engine if the fuel pump was only emitting a small amount of fuel.
This is why you have to test for PRESSURE and VOLUME.
There could lso be a problem with the FUEL PUMP PRESSURE REGULATOR of which test procedures need to be performed.
