refusing to run

[loriannjo]

I have a 99 GMC Sierra 1500 that started trying to stall out on me this morning. Then when I took it for a short drive it stalled out and wouldn't run for longer than 30 seconds, or till I tried to give it the gas. It has all new plugs and plug wires. After it stalled and wouldn't stay running I decided to change the fuel filter. Now that the filter is it will try to, and will start for just a few seconds but dies instantly. It wont even try to start again till I have repeatedly turned they key on for 10 seconds and turned it off. Does anyone have any ideas on what's wrong and how to fix it?

[SierraK1500]

Hi
(Love your pic)
Have the vehicle towed to your local GMC Dealer and have them fix it.
On a quiet day with your door shut and windows down, turn the key on.
You should hear the fuel pump in the truck come on and go back off.
The pump runs when the engine is running. You could have a bad fuel pump relay or problem in the fuel pump circut.

Good luck to you...let me know how you did!
John

[loriannjo]

Ok when the windows are down I don't hear anything. But I did get it to start and run for about 5 minutes, at which point it started bucking and died again. I would take it to the GMC dealer, but I don't trust the mechanics there...in fact I dont really trust any mechanics. If at all possible I would prefer to fix it myself.

How would I go about testing the fuel pump relay and such?

[SierraK1500]

Well you can locate the wire going to the fuel pump and connect a visual item such as a 12 volt lamp to the circut in parallel with the pump. If the fuel pump circut cuts out the light will go out. And of course the engine will stall. You might as well replace the fuel pump if the engine dies and the light remains on. Some of the pumps have overload protection built right in the pump. When the overload kicks in the pump will die. These pumps are submersible and will use the gas in the tank as a natural heat sink. Some of the pumps are mounted to the frame of the vehicle. I can remember my old days as a VW mechanic, and had to run a line from the battery to the fuel pump to drive the vehicle to the shop to repair it. That always had a bad wire in the harness.
Get yourself a book on the wiring in the truck and locate the fuel pump circut. If the pump and light dies, replace the relay. The relay is releasing before it should and that can be a number of things to point to the relay going bad itself. I do strongly recommend a good mechanic that can diagnose the problem and repair it for you. I have a 2001 Sierra
which I am madly in love with. Its a good truck and has not given me problems. You can personally email me of you wish or stay with the forum. I will try and help you anyway that
I can.
John

[fuzzypuppy]

Hello. first step if I were in your shoes is to buy the Chiltons or Hayne's book at your local auto parts store, and begin by following thier trouble shooting procedures, This board is a great source, but I have found these books invaluable and as necessary as any tool I own. I still have every book for every car I have ever owned over the past 25 odd years. you can get a general idea of location of componants as well as fairly detailed test proceedure's, as well as a good referance for all the specification's for your truck.
As far as your particular problem....the other poster had a good guess, but.. as to an 'exact' diagnosis I would be hesatant to say untill you have done a few basic tests to narrow your problem down some, such as, fuel pressure check...etc.
I applaud you for digging your heels in and going at the repair's yourself, not many do this these days, I also feel as you do with mechanic's, not that thier all bad,, just that, I have yet to ever find one who I would allow to crawl around in any vehical I have ever owned, and trusted my family to travel in.
besides when your stuck on the side of the road at 3 am a mechanic is not going to come help you, but what you learn from doing these repairs at home now can many times help you figure out a way to at least get your truck going long enough to get ya home.
I have taught my wife, daughter, and have even started teaching my 5 yr old son the basics. If you do have more questions please DO post on the board, there are many good people on here that would be glad to put thier 2 cents in, and as the chiltons book, this is just another resource,
Well there's my 2 cent's worth, and good luck

[loriannjo]

Since I don't have the equipment to do an exact diagnosis I'm having it to towed to our local brake and muffler shop to have them test it. Once I find out what the exact problem is I will fix it myself...providing its something I can do. I do have a Chiltons manuel, but unfortunatly most of the tests it told me to run require things I dont have...like a fuel pressure gage.

I do know that there are some good mechanics out there, just havent found one yet. The last mechanic that worked on my truck really screwed around with me. It needed a new engine and he refused to order the one I found saying the one he found was much better. despite the fact that it had twice as many miles and he never even called to get the info on my engine.

Thanks to both of your for your help.