question about 93 blazer?

Question

I replaced all the fuel lines and fuel pump and fuel filter and all of the sensors had a complete tune up. I have had it @ 2 shops costing me about $ 1200 in labor and parts. the fuel pump has been replaced 6 times. this has been a on going problom with this truck. The fuel pump kicks in when it feels like it. I have tryed going to diffrent places for gas and it doesnt seem to make a diffrence. it seems like a connection to me but they have been all replaced. and each time it goes in the shop they check every thing . does any one have any ideas on whats going on?

Answer 1

I would measure the current in Amperes being drawn by the fuel pump. An easy way to do it is using a clamp on Digital Multi-Meter (DMM) that can measure DC amperes. Get a specification for the fuel pump to see what it should be drawing. If the reading is too high or low, then one reason could be a high resistance battery feed circuit or ground connection to the pump. When you have excessive resistance in the battery wiring to the pump or because of a poor ground connection to the pump, then the excessive voltage drop will cause the pump to try to maintain it's power output and burn it out sooner which is true for any DC motor. A comment in an answer below suggests the pump relay may be the culprit. It's electrical contacts could be burned which would create a higher resistance connection to the battery and excessive voltage drop to the pump motor.

Answer 2

Six replacement fuel pumps certainly seems to eliminate a pump problem. The factory fuel pump is electric powered, and is located in the fuel tank, unless your vehicle has been modified. The pump is powered by a fuel pump relay that energizes in the ignition run key position. Your question did not mention replacement of the fuel pump relay which is alot less expensive and labor intensive than a fuel pump. The problem definately appears to be electrical in nature. The problem diagnosis would be best accomplished by checking for system voltage in the wires leading into the fuel pump when the problem occurs, and if there is no voltage present tracing back from that point to relay, ignition switch, fuse, etc. to locate where the open circuit is located. If that is not feasible a reasonable guess would be fuel pump relay or loss of electrical "ground" at the fuel tank pump unit.

Answer 3

first thing you need to do.
Get a Haynes Repair Manual at the local Auto Zone or auto parts store in your area. It will troubleshoot and show you how to fix your vehicle. Also on the Auto Zone site has a section for vehicle maintenance

When you come in they must see "Sucker" on your face. Then you have some sorry mechanics. Most are there to get your money and hard to find good ones nowadays.

I hope you took it to a shop where you at least have a warranty on it. For that much money, I know for a fact I could have fixed everything, a tune up, tranny and rear end oil change and throw in some new tires and still make a killing. hahaha But then I do the work at home and guarantee my stuff. No overhead just pure profit for me. Anyway, buy the book and here is a little something from auto zone troubleshooting section for your vehicle. Check out the tech bulletins and also the other repair tips.
http://www.autozone.com/servlet/UiBroker?UseCase=S001&UserAction=viewSimpleDiagResultsInfo&Parameters=Engine+Compartment|~17|~Driving|~22|~Power+Loss|~140|~Feels+like|~1&FROMJSP=type

Answer 4

Mike, Mechanical pumps run off the camshaft.. I doubt a 93 would be using one anyways. The first thought I have would be the fuel pump relay. If it doesn't deliver steady power to the pump while it's running, the pump will burn out quickly. You should be able to hear the pump in the tank. Listen for a hum. It should be steady in pitch.

Answer 5

you did not specify if it was an electrical or mechanical fuel pump...if it is mechanical...you have the wrong one...or a bent crankshaft...good luck...

Answer 6

What do you mean it kicks in?