1989 Toyota pickup (SR-5) Won't Start!

So my husband bought an 89 SR5 that ran. In order to get it to smog here in California, we had to replace the O2 sensor, and the Mass air flow sensor/meter. It ran for about a week after that then abruptly died and wouldn’t start again. I went through all the steps for trouble shooting, we have spark and no fuel and have changed the circuit opening relay, all of the fuses, the fuel pump, fuel filter, the throttle position sensor and even the mass air flow AGAIN because it was stuck open we checked it. Even though I have changed all of this and checked and rechecked all of the fuses there is no power at the fuel pump. Every time I chase the wiring from the pump I get stopped at the circuit opening relay. I’m about to try to hard wire the fuel pump to the battery or distributor if I can’t figure out why it can’t kick on. Any suggestions would be appreciated. :slight_smile:

Pull the fuel pump relay…use a piece of wire and bridge the two open slots that once housed or accepted terminals 87 and 30…this will send 12v to the pump… with the pump out…verify voltage at the pump and if you have it…it should be running and or HOT to the touch…IF NOT…you have some wire chasing to do…which is straight forward… ALSO…DO NOT …DO NOT UNDERESTIMATE YOUR GROUNDS…check em…clean em…they are equally as important as the hot side
IF you already know you dont have voltage at the pump…you already know where your trouble lies…you need to chase some wires and grounds. ALSO…REMEMBER TO SMILE AND HAVE FUN CHASING WIRES…dont overlook any plastic connectors along the way…pull them all apart (fuel pump associated) and make sure they are making good contact


we did that with the old pump and it wouldn’t run at the full 38-44 psi. So I changed the fuel pump last week. At the connection to the pump above the tank there is no power going to the pump at all.

If jumping the relay will not provide power to the pump, I would run a new 14ga wire from the “ON” post on the ignition switch to the pump. With this set-up, when the key is on the pump is on…It’s not necessary or recommended to go directly to the battery…

I was afraid of having to hard wire it. The ignition is a good idea though. Thanks. (And I was going to put a toggle switch in the dash so that the pump would only be running when the switch was on)

I’m assuming when you say it won’t start, you mean it cranks when the key in in the start position, but it never catches and runs. I’m not familiar w/you particular vehicle, but I own an early 90’s Corolla, so they may have some thing in common. I think the fuel pump voltage might appear on the diagnostic check connector in the engine compartment, might be easier checking it there than at the pump. Look under the hood for the decal that shows the config of that diagnostic connector. If there’s a label saying somelthuing like FP, that’s probably the fuel pump voltage. For the circuit opening relay to turn on, there is probably a main engine relay that has to turn on first, then the ECM must detect that the engine is rotating. It’s called the circuit opening relay I think b/c in the days of points ignition system, it detected the points opening to verify the engine was turning. The problem may be that the ECM is thinking the engine isn’t rotating during the cranking phase, so it never turns the fuel pump on. The ECM probably measures the distributor turning to determine the engine is rotating. Maybe one of those hall-effect sensors under the dist cap has failed. Best of luck.