Will not start

Hi,

If you are questioning if it is a fuel issue, try this. See if the engine starts for a couple of seconds when using starting fluid. If it starts and then stalls, you'll know it's a fuel-related issue. Also, you could check fuel pressure. Here is a link that explains how it's done:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Also, I attached the wiring schematic below for the pump. There are a couple of relays to check and fuses.

If you look at the schematic, note that I highlighted several of the wires that are all tied together via a relay and fuses. I need you to check the fuse. Under the left side of the dash, locate fuse number 3 (25 amp). Inspect the fuse to make sure it is good and also confirm there is power to and from it when the key is first turned on.

Next, check the engine component power relay in fuse panel B.

If there is another relay that has the same part number, switch them. If there isn't, here is a link that explains how to test a relay:

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

Let me know what you find. Also, you can perform the aforementioned things in any order. However, I do suggest trying with starting fluid first. If it doesn't start, then the fuel system, at least at this point, should be bypassed and focus placed on the ignition system.

Take care,

Joe

See pics below. Note: There were three pages of schematics. I had to cut each one in half to make them readable. So, every two pics are from one page. I did overlap them so you can follow from one to the next.

I forgot to do the starter fluid first before asking the question. I knew i should have.

LOL, no problem whatsoever. Let me know what you find. I'll watch for your reply.

Joe

Sprayed some starting fluid after removing the throttle hose, but nothing happened. Also, no codes are being set after several times of trying, strange.

Hi,

Based on that, I suspect you lost the ignition spark. If you haven't already, please confirm that for me. I'm suggesting it because if it has spark, then there could be a timing issue or compression issue.

Here is a link showing how to check for spark:

https://www.2carpros.com/articles/how-to-test-an-ignition-system

One last thought. If it's possible, could you record it cranking and upload it for me to hear? Usually, I can tell if there is an issue with timing or compression. If you do it, have a helper crank the engine while you record it from outside the vehicle, near the engine. That way I'll have a better chance of hearing it.

Let me know. Also, if you don't get to it for a couple of days, I wish you and your family a great Christmas.

Joe

I will record a video, but familiar with the sound if an engine which has a broken chain/belt or a lost compression, i know what you mean. I will check spark and send you a video for the engine sound.

Sounds good. I'll watch for your reply.

Take care,

Joe

Not hearing the fuel pump. See if these make any sense.

Here we go:

Still no codes, did a compression test and they were around 130-135, all very close to that. Added a drop of oil and it was pretty much the same. Even if compression great it should start, i have had Audis with 80 PSI and starting just smoking.

Checked fuses on left of dash all good, same for ones in trunk.

Hi,

The engine does sound normal when cranking. I agree with you. Is spark lost? As far as the scanner is concerned, either I'm missing it or there is no change. Did you also check the relays I indicated?

Since you don't hear the fuel pump, we need to check power to it. I attached the diagnostics below for the fuel pump. (Pics 1-5). The remaining pics are the diagnostics for the ignition system. I have a feeling there is no spark. I also suspect this is related to the ECM, but I can't be sure until these tests are completed.

Let me know what you find or if you have other questions.

Take care,

Joe

See pics below.

I removed the plugs, and they were dirty. cleaned them all up and that's the only time it starts for 2 seconds and shuts off. It is smooth when it starts and sounds really good. I took a video of it to see if there is anything you are seeing. No stored codes but pending codes are two misfires which still should have the car run at least.

Hi,

The fuel trim at 99.2% indicates it is not in use at that point, so it's nothing to consider. However, am I reading the fuel rail pressure correctly? Is it 15.95 PSI before starting and then drops to 15.5 PSI?

Joe

I will have to redo it and see. But yes, it is showing 15.95 then drops to 14.50.

The pressure is too low. That can't be right. Let me know. This vehicle has a supply pump and a high-pressure pump. At the rail, it shouldn't be that low.

Please reconfirm if there were any trouble codes at any point, and what they were.

Joe

Possible hpfp or something else, plugs maybe fouled too from all the fuel.

Were all the plugs wet? The fuel rail pressure sensor may be bad. I'm questioning of the fuel pressure regulator valve is stuck open. That would dump fuel and not allow pressure to build.

I attached diagnostics below for testing. Let me know if you are comfortable doing this.


Joe

See pics.

Yes, pretty much, once cleaned with brake cleaner it started. For 2 seconds, several times.

Just like in the video.

I don't understand how spraying starting fluid in the throttle doesn't do anything, maybe because the plugs were fouled.

See my last post above and let me know.

Joe

Oh, sorry i missed that. Will check it tomorrow, so the regulator is the part with the harness on the hofp?

It sounds like the plugs are getting soaked. That is the likely cause of the starting fluid not working. And yes, it is on the HPFP.

Joe

I also checked spark on one of the plugs and it is there. I will check the fuel rail pressure and see.

Disconnected the wire to the rail sensor and it started a bit longer than before it shut off. Now here are the values again while ignition is on.

While starting. Can the cam follower if worn out cause this low value or that has no effect on it?

And i assume we are talking about this sensor on top of the hpfp correct?

I also checked the relays in the plum e-box, switched them around, no change.

Yes, to the sensor. If I'm reading the scanner correctly (when cranking) it's showing 5.1670 MPa (megapascal) correct? That works out to nearly 750psi. At idle, I would expect that to be lower. See pic 1 (435 PSI at idle).

Looking at the first pic you provided, it is showing the HPFP 5.1670 MPa and 2.9 PSI below that. I'm not familiar with your scan tool. If the engine isn't running, I don't understand why the HPFP would be that high and the (2.9 psi) which I think is the supply pump, to be so low.

Please let me know if I am reading that correctly. The HPFP is a mechanical pump, so I would expect that to be low without it running.

Let me know.

Joe

I used my Maxisys this time. There are so many fuel numbers and I always get confused. But car always start, at least for a second, only in the am. I suspect the hpfp/sensor, or the cam follower

Hi,

I can't see the actual readings/values when cranking. If the plugs are soaked, my first thought is the HPFP sensor.

Let me know.

Joe

Changed the pump with the sensor, same results, ugh. I took some videos not sure if any numbers would make sense to you. All taken while starting. The only thing would be to replace plugs, but i doubt faulty plugs wouldn't let the car run at all.

Hi,

When I try reading the scanner, it is sideways, and I see no numbers. Your pics above show it normally but upside down. I'm not aware of what readings/values you are seeing.

As always, check to make sure that the plugs are getting spark and let me know what happens with starting fluid.

Joe

I checked the spark, and it was there. I will check again. I will try fluid again as well. I just took pictures of the scanner numbers from the video and turned them up right. All these are while engine was turning.

In pic 3, it shows 1.45 PSI. Is that the supply pump? If it is, take a look through the pics below. That should be over 50 PSI.

Also, please understand not being there with you makes this difficult for me. If I repeat a check, let me know.

Let me know about the pressure in pic 3.

Take care,

Joe

See pics below.

Yes, i know diagnosing behind a screen is difficult. I don't mind checking again. Wouldn't that mean that it maybe the fuel pump not pushing enough? I will need to check there as well i guess, but there is fuel when i removed the hpfp, but maybe not enough. Cam follower is also good. And with regards to the number and since there are so many fuel numbers that is why I am confused. This one in picture 3 for example just says fuel pressure. Very confusing to have so many fuel numbers you know.

Picture you sent is for fuel pump, i guess. Not sure i will have the right fittings to measure pressure there.

Hi,

I totally agree. Today's cars have too much of everything. LOL As far as the pressure in pic 3, I am assuming that is from the lift/supply pump because all others indicate HPFP. I looked through the specs and from what I'm reading, it should be over 50 PSI. It indicates pressure in bar, 3.5 - 6 bar. That works out from 50 PSI to 87 PSI. If the 1.45 PSI is correct, that is equal to just under 0.1 bar.

Let me know.

Joe

So, i decided to remove the back seat and check the fuel pump. First, is t there supposed to be a feed and a return line? I only see one. I hear the pump when the harness is connected and i don't when the harness is off. Removed the fuel line and very little cane out. Left the line off and turned the ignition on, none came out even though there is some gurgling sound. Is this normal?