Well yesterday I was driving home and my truck just killed and would not start back up. I was having problems with it bucking (like it would cut out for a second and then start again) but this time it didn't keep going. Ive changed the fuel filter, distributer cap, rotor, and module, wires, plugs, coil, air filter, and its still not starting back up. There is no spark and there is no fuel. I had a wire go from the positive wire on the high pressure pump to the positive wire on the battery and I can here the pump run and the back low pressure in tank one too. I know its not the fuel pumps but it just stumped me. I looked on google and a guy had the same problem he said it was a positive wire going from the battery to the ignition that had corroded out. I dont know what wire that was so i'm not sure if I can fix that. I used a volt meter and the coil is getting 12 volts but im not getting spark. I also used the volt meter to test to see how much volts the fuel pump was getting and it was only 4.56 and when I switched to the other tank it was only 1.56 volts. someone help me please this is frustrating!

 

Let's fix one thing at a time.

Fuel system: When you turn the key on, do you hear the fuel pumps run for 2 seconds? If so, then check your fuel pressure with a gauge. There is a schrader valve on the fuel rail on top of the engine.

Once you are sure that you're getting enough fuel, then we can figure out if the injectors are firing and if you're getting spark.

How do you know you're not getting spark?

 

the pumps do not turn on when i turn the key....there is no fuel pressure. and when i checked the spark i pulled the number 1 plug and turned it over while i touched the end of the plug to a ground source. it has to be something electrical because 2 pumps going out and no spark doesn't just happen all at once

 

When you turn the key one click you should get the check engine light. If you do the EEC relay is closing as it should & the PCM is powered up.

Next thing to check is whether you can turn the pumps on manually. See this link turn the key to run & run your jumper to any handy ground or the negative post of the battery.

Do the pumps run?

Dont worry about dsconnecting any fuel lines just connect the jumper as shown at this link.

http://www.superhighoutput.com/tech_view.php?id=5

 

I found the problem, as I was trying to unhook the cover for the eec test connector I found that one of the wires fell out of one of the relays. It was all corroded and must have been like that for awhile. This was also the problem that caused the "bucking" when under load. I can now shift to second without it stalling at higher rpmsSo if anyone elses truck is bucking check the black and orange wire going into the fuel pump relay.

 

Congrats on the fix, glad you found the problem.

 

I had this happen on a '91,it acted up for over a month before I found it,when I did.I replaced the pigtails on all my relays.Listen to your truck when you shut it off and get out,I had my '89 Bronco's fuel pump relay stick on,over 200 miles from home,when I came out of Burger King,the main pump was burnt out,had I listened,I could have tapped on it or unplugged it and saved a lot of money and trouble.