Bad Fuel Pump Relay Symptoms: 6 Common Failure Signs

Bad Fuel Pump Relay Symptoms. Learn the warning signs of a failing fuel pump relay. This video explains symptoms like engine hesitation, hard starting, rough idle, losing power, and trouble codes.

The fuel pump relay is a crucial bridge between your vehicle’s electrical circuits and the fuel pump. When you turn the key to start the engine, the fuel pump relay closes to provide 12-volt power from the battery to the in-tank fuel pump, allowing it to pressurize the fuel rail with up to 60 PSI of fuel pressure. This allows the fuel injectors to spray fuel into the engine so it can run. Once the vehicle is running, the relay stays closed to keep the pump flowing.

A faulty fuel pump relay affects the electrical power supply to your fuel pump, which can cause all sorts of performance issues. Diagnose relay problems before small driveability issues lead to full engine stall or no-start.

What is included in the video:
1. Intro to fuel pump relays and how they work
2. Symptoms of a failing fuel pump relay
3. What happens if the fuel pump relay fails completely
4. Why fuel pump relays fail over time
5. Replacement parts cost $15-20 USD.

Why Fuel Pump Relays Fail
There are two common reasons fuel pump relays eventually fail after years of cycling on and off:

Heat and electrical overload killing internal components over time. The contacts essentially wear or melt away. Newer solid state relays avoid this issue and last longer.
Low voltage from a failing battery or charging system prevents the relay from closing fully. The fuel pump is unable to pressurize without full 12+ volts. Critical systems like ABS, stability control and variable valve timing stop functioning as well until voltage is restored.

Disclaimer: This content is for educational purposes and should not replace professional advice. As an experienced mechanic, I aim to provide helpful insights, but I'm not liable for any damage or issues arising from the application of this information. Always consult a qualified mechanic for specific vehicle needs. Viewer discretion and responsibility are advised

[chelseycombs]

Thank you so much for posting the video. I found it very helpful although I would like to pick your brain about an issue I am having with my 2012 chevy malibu that none of the videos cover.

I bought it early March and after about 10 days of driving, it wouldn't start one morning. I did some research, figured out it was the fuel pump relay (or so I thought). I replaced it and it started up just fine. 2 days later, it wouldn't start again. I replaced the fuel pump relay again, and it started up just fine. Until about 4 days later when it wouldn't start again. This time I was sure that the relay couldn't be bad again so I pulled the fuse box out and inspected the wiring. I didn't see anything or feel any heat so I tried starting it and it started perfectly.
At this point I was confused but it drove fine for a few days until it wouldnt start again. Now everytime it doesn't start, I simply lift the bundle of wires up or wiggle them around and the car will start for me but only lasts a couple of days before needing to be moved again.
I have watched dozens of youtube videos and talked to a few people about this and they seem puzzled so I will take any and all advice!

[LegalAssistant...]

OMG Thank you! This is exactly what is wrong with my car! I'm so thankful for your video! Keep up the good work! 👍🏻

[CrankyBarista]

I would like input or advice...
I have a 1990 Ford F150 duel tank (manual) and it been having trouble starting, idling and the check engine light is on.
It also pushed fuel from the front tank to the rear tank, then overflows the rear tank.
Assumed it was the fuel pump malfunctioning.
Took it to a mechanic who is familiar with Fords (and older models) and after extensive diagnostic said it wasnt the fuel pump (they work fine) and eventually told me it needs a new PCM.
After watching this video, I wonder if it could be something as simple as the fuel relays (as both problems present the same symptoms).
Id like to safely assume the mechanic checked the fuel relays (but you never know).
Its going to cost me about a grand to get a rebuilt PCM and after hearing from several mechanic sources that its hardly (if ever) a bad PCM, Id like to avoid spending 1k (on such an old truck) only to find out later it was something simple like the fuel relays.
Any suggestions???

[TinyT]

Hello thankyou for the vid.

I have a direct injection engine and have noticed when i turn off the car. The fuel injectors are randomly spraying every 5 mins for about half an hour. The car then finally goes to sleep. Can a faulty relay be the cause of this?

Regards

[lindatorres]

Thank you for sharing. I think this is a what my car did today

[kaybee]

Hi there I have Opel Corsa 1.4 that will only crank unless if I give it a boost by Stepping on the accelerator and in order for it to idle well, I will have to leave the accelerator when the engine is a bit warm.

[ifounditforyou]

Should i change fuel pump relay after changing the fuel pump ram 1500

[siteralynell]

My daughter has a 2013 KIA Forte it will not take gas and air pressure comes out the tank when opened . The gas just spills outside the car when pumping it. Please tell me what could cause this issue?

[hananmartin]

Might a failing relay be related to the fuel gauge not working? I have already replaced the fuel level sending arm, but the gauge is stuck at below empty. Occasionally, it will read correctly, but it lasts just a few minutes before it goes to reading empty. Any ideas? Thanks.

[BeatBoomDotCom]

I stopped at the Coney Island to get something to eat but before I got out the car was running for about 5 minutes so I went in to Coney Island and when I came back out the car started with a very rough idle and then he died and I kept trying to start it up it will crank up with the very rough idle and then die again to the battery died. After sitting for about 15 or 20 minutes I finally got a boost in a crank right up and ran normal. Then today I made a couple of errands and when I got back in front of my house the same thing happened from last night I turned it off and when I crank it back up it ran really rough and died and I kept trying to start it up running rough until the battery died again

[OmegaFTW]

i have an issue with my mk4 golf 2.0l where on hot summer days after driving for a bit ill lose throttle and my car will start to stall out. if im on the highway itll pick itself back up but if i dont want that to keep happening i need to pull over and wait for my car to cool down. i originally thought it could be my fuel pump is on its way out, but im wondering if the relay could also be causing this. there is also no check engine light so i cant scan for codes, the only way to pin point it would be to get the software to do a live data scan but thats a few hundred dollars

[eileenbarber]

that for this video! I am wondering if this is the problem with my 2007 Saab. sometimes it starts and runs fine but then after a short while it starts to sputter and the fuel gauge drops down to E. I am lucky to get it over 15 mph at that point. When I turn car off, I occasionally here some loud clicking from area behind the stereo system. Thoughts?

[kingatticus]

My 1998 Honda crv . It will start then dies instantly. I can crank it back it starts then dies over and over . What could this be ? Any help would be appreciated thank you

[Jesuscaballero]

Whats the best way to check if your fuel pumps out, if ive checked both fuses and even swapped the fuel pump relay with a fifferent relay and stillwifes grand caravan 2015 wont start.

[ThomasNkuna-mc]

Hi, I have got a V8 old car mercedes, when cracking engine all injectors they spray all the time, is it normal?

[fashion.vibes]

I have nissan armada 2018 rpm is not cantrol what should i have to do

[VTXDEMON]

Good morning, I’m working on a 2009 Kia spectra5 and I’m currently having a fuel issue, it drops in RPMS every now and then and the car will randomly turn off sitting at lights.
Currently replaced the fuel pump due to the faulty pump not turning on.
I’m into replacing the filters and seeing if the cause of the engine light kicking on, it says I have lean fuel pressure on my OBD scanner and a PCM failure to send correct A/F ratio, could that be a relay? Thanks again!

[billgako]

relay stuck some times ....and fuel pump always

[darrinmowrey]

Can the relay be stuck closed? My fuel pump is on constantly with the key on engine off

[jonathanhernandez]

I have a 2018 Camry that cranks perfectly on cold starts but has long cranking to start when warm starts( after I’ve driven it and parked for like an hr then turn on again) only happens when the engine is warm