Strange misfire?

Hi,

The fuel pump is certainly a suspect. Do you have a scan tool to see specifically which cylinders are misfiring? The blinking CEL indicates it is happening.

Also, does the fuel pump always shut down? Does the engine ever continue running? If so, if you have a live data scan tool, check the short-term fuel trims when the engine is at operating temperature and let me know what they are.

I will watch for your reply.

Joe

Hi thanks for responding,

So, the pump went out and is not working, it does not work at all, it just stopped working randomly and will not work, you cannot hear it prime. This happened awhile after I was trying to solve the misfire problem. So, I’m thinking maybe it was the issue all along. It was cylinder 1 that was misfiring for a long time and then it moved to 2. I tried swapping coils, replacing coils and plugs, checking injectors. Now all of a sudden, the fuel pump just stops working. Before I replace it, I just wanted to know your thoughts. I don’t have a live data scan tool. And the cheap tool I have won’t grab any codes till I turn engine on, as I said, it’s been awhile since I first worked on it, I had to charge battery and was hoping maybe I could grab some codes, but nothing without running the engine, at least with the tool that I have. The fuel pump really does seem suspect to me, what do you think? The 2.7 has a fuel rail and cylinders 1 and 2 are furthest from where the fuel enters the rail, may there wasn’t enough pressure from the pump to send enough fuel as needed? I don’t know, just a thought. I look forward to your response, thanks, God bless.

Hi,

Will the engine start if you use starting fluid? If it does and then stalls, we can confirm it is a fuel issue.

Next, there is a chance we aren't getting power to the pump. There is a fuel pump relay (circuit open relay) that may be faulty. It is located in the vehicle (lower left side of the dash). Also, there is an EFI relay and fuse and an ignition fuse that may be causing issues. The injector fuse/relay is under the hood in the relay box and the ignition fuse is under the dash.

Check these things. Here are two links you may find helpful:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Let me know.

Joe

See pics below.

Hi, sorry it’s been a while. I’ve been very busy. I posted another question last night on here about my truck,now thinking of it I should have just replied to this. Sorry. I checked out relays and fuses and everything seems good. I really think it might be the ECM, I know they don’t go bad often but, the misfire that travelled randomly after a while and now no power to fuel pump, I think that might be it. Any thoughts. All of the stuff I’ve replaced also has no sign of air leaks, and it won’t let me read any codes, it won’t turn on due to no power to fuel pump.

Hi,

No problem whatsoever. I feel bad it isn't fixed. LOL Have you checked the circuit open relay to confirm if it has the power it needs? If the fuel pump still isn't running, we need to check if there is actually power to it. You may have a faulty pump.

Let me know.

Joe

See pic below.

Thanks, how would I go about checking for power, all I have multimeter, I don’t have test light or scan tool?.

Hi,

You could use the multimeter. Set it to voltage, connect the negative connector to a known good ground location, and then use the positive side to probe for power.

Here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Also, here is a link that explains how to test a relay and its circuit:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Let me know if this helps.

Take care,

Joe