QuestionI check both blue 20A slow blow fuses and both were ok. i checked the fuel pump relay plug with test light and did have currant there.I test the fuel pump with a jumper wire and it do work. Don't know what else to try
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I did a engine swap on my Hyundai. I hooked everything back together and now I cant get any fire to the fuel pump. I changed the relay and had no luck.I ran a wire to the fuel pump test plug and the pump do work, but wont start that way. but I can shoot a little gas in the throttle body and it will fire but just long enough for that gas to burn off. Is it a fuse for the pump, or is it possible I may be over looking a loose wire or maybe a fuse link somewhere. Any info would be greatly appreciated. Thank You
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You might check the large 20A blue slow blow fuses to be sure you didn't inadvertently blow one of them. Otherwise, most of the fuel pump circuit is inside the vehicle. The ECM controls the fuel pump relay. We know the ECM is operating because the car will run if you manually put gas in the intake.
AnswerIf the fuel pump runs and supplies fuel pressure if you apply power to it, it seems fairly obvious that your problem is that you're not getting fuel pressure to the fuel pump.
(I'm presuming you checked the fuel pressure and power to the pump and verified that it's an issue with not having fuel pressure due to no power there and not some other sort of fuel delivery issue. If you haven't done this, you should check the fuel pressure and check for power to the pump before we embark on a wild goose chase.)
To start, you'll want to check the wires at the fuel pump relay. With the relay plugged in, here's what you should have:
1. White/red wire (pin 1): battery power at all times
2. Red/white wire (pin 2): power when attempting to run the vehicle; resistance through the fuel pump to ground when the fuel pump is unactivated. This is the feed to the fuel pump. Based on your description, I expect you won't have any power here until you locate and repair the problem.
3. Red/white wire (pin 3): power when ignition in "on" or "start" position.
4. White/yellow wire (pin 5): ground when attempting to run the vehicle. The ECM grounds this wire to close the fuel pump relay and run the fuel pump.
I know this will be difficult because of the two Red/white wires. It's my recommendation to look at the schematics at www.hmaservice.com to get a better idea of what's going on. If you don't already have one, you'll need to register for a free account there. The site requires Internet Explorer, and you may also need Adobe SVG Viewer (a free download) to see the schematics.
