Hello, I have a 1990 Mazda B2600i 4x4 pickup that I've owned since 1995. It has had this very intermittent problem lately that I've had a hard time pinpointing. It will sputter and die sometimes when running. Sometimes it would start back up after a few minutes, sometimes not till the next day. Sometimes it will run for days without this happening.
I tried several different things, each of which I thought solved the problem (because of the intermittent nature of it), but it came back. I changed the fuel filter, checked the fuel line pressure, drained the fuel out of the tank and refilled with new fuel. I did each of these at different times when the problem came back. ( The old fuel turned out to be ok anyway because it ran fine in our other car.)
I also have had the coil checked. The truck gets good spark. The injectors are working fine. I also checked the ignition switch. My check engine light only comes on when when the engine dies.
The last time this happened I let the truck sit for a long time. Then a friend came over and jumpered the fuel pump priming wire under the hood, which I've done after changing the filter and checking fuel line pressure. I took the truck and got It Smog tested. It ran fine and passed smog on the first try. (I live in CA, by the way). I put about 85 miles on it, then the truck died again. I jumpered the priming wire and was able to drive home, but had to stop and jumper it one more time before I got there. (I only put the jumper in for 10 seconds like the Haynes manuel says.)
I checked the fuel pump relay accorcing to the manual. The resistances and Voltages were as recomended. I think the relay may be going bad, but it checks out good on the multimeter. Is there any thing else that may be sending a signal to the relay to make the fuel pump shut off? I'm not 100% sure the fuel pump is shutting off, but I now think this may be the problem. If the Fuel pump was going bad, wouldn't it go out all the way? It always comes on when I jumper the priming terminals.
Im sorry this is so long. Any help would be appreciated.

Medieval

 

Hi Medieval.

I think this may be relevant to your situation. I owned a 97 Chevy Cavalier that had similar symptoms as your truck. The car would run great for a while and all of the sudden just sputter and die. Sometimes it would chug along like it was starving for fuel. Eventually it gave up one day and died all together. It turned out to be the fuel pump. I replaced the pump and that problem went away.

I once thought as you did. If the pump was failing, wouldn't it just quit working permanently? Well, it turns out, not in this case.

Hope this helps

 

Thank's Mercenary. I'll keep that in mind. I do believe it could be the fuel pump now.

Medieval

 

Yea, give it a go and replace the pump. I don't know how much one would be. My Cavalier pump was quite expensive. Somewhere in the neighborhood of 700 bucks or so. Hopefully it's not too pricey a fix.

 

i just bought a new fuel pump and tank for my 90 b2600i pump was 150 the tank the same i have a problem of to much fuel i can drive it but it fowls the plugs

 

Here's my old fuel pump relay story, different truck. I once had a '75 Chevy Luv (Izusu) that ran great 99% of the time, but the other 1% wouldn't run at all. I had a mechanic look at it, but such an intermittent was hard to trace. I finally figured it was intermittently not getting any electrical current to the fuel pump relay (figured it out as the circuit was tied into the alternator warning light, and the glow would look different when it quit), and was going to replace the fuel pump relay (because it was easier and cheaper than tho guess with fuel pump), then found by unplugging and re-plugging in a wire harness under the dash that I restored better electrical connection to the circuit, so fixed it with no parts !