2018 RWD - Cold starts turn over for ages, warm starts fine

[shogran]

Hi all,

Hoping someone might be able to help with a weird starting issue. Got a 2018 2.0 RWD that turns over for ages (approx 15-20 seconds) EVERY TIME before starting from cold, even when pumping accelerator. Eventually starts and runs perfectly and any subsequent starts while still warm or only been off for an hour or so it will start first time after the expected amount of time.

ForScan is showing me that it's flagged "P008A:21-2F Low Pressure Fuel System Pressure - Too Low". This is very intermittent though and when cleared does not appear every time the cold start issue occurs, it's somewhat random and maybe presents 30% of the time. It does not impact drivablility with no limp mode or noticeable hesitation.

My battery seems to be okay and I measure 12.5V under the bonnet between the positive terminal and jump point neutral.

I've replaced all 4 injectors in the last year for a separate issue, and checked they are all seated tightly and doesn't appear to be any leaking at fuel run off pipes or at base of injectors.
I have changed the fuel filter also in the last year and had the fuel tank dropped to add a feed for a diesel heater, so I've checked the filter housing and tank connections for leaks. I did notice one of the fuel line connectors that connects the pipes from the sender on the tank to the main line under the van looked like it had a coating of fuel on it. I disconnected it, checked the o-rings were intact and re-seated it, then cleaned it up. After a few runs it's looking a bit mucky again.

I have since replaced this elbow with a replacement that no longer leaks, and this has not made a difference to my issue. At the same time I also replaced my fuel filter (despite it being relatively new), the one I removed was still perfectly serviceable and clean, but put the new one in to be safe, unfortunately no joy.

Any advice would be greatly appreciated, and any information I can provide that would help I'm happy to do! Very frustrating having to sit there turning over the engine every day for the first time, I know it WILL start, it would just be nice to understand why and have it work as intended.

Cheers,

Josh

[metalworker0]

i don't know you've seem to have gone through the lot, everything but the in-tank fuel pump and the fuel pump module./

i've done a bit of research into this before .. few weeks back.. hope you dont mind be just copy paste my answer .


OK it's generally called the low side (low pressure side)

Consists of.
Fuel lines
Pump inside the tank - often called the "SENDER" note - also has it's own mesh filter
Fuel module above tank - often called many names including relay and unit
The wiring
Fuel filter

Not to be overlooked: blockage in fuel breather system

sender pump and combined fuel level sensor etc

its inside the tank, when a ford dealership finds a fault with this they replace the whole thing , the pump belonging to this unit can be found separately, if you do your research and track it down .,. but not under any specific vehicle brand.

Fuel module
Not pointing to the fuel pump relay as at fault--- its just something else to check... this is just info i picked up on it last time i looked into it,
Location on top of the tank - accessible without dropping tank
The part number is 5336501, confirmed as is located above tank on the parts diagram...fits several ford cars as well as mk8 and custom ecoblues

On ebay can be found with 5336501

Some call it a relay .. some call it a module .. some call it a unit ...that's were the confusion comes in even ford who advertise on ebay don't know what to call it .

Parts diagram calls it "control assy - fuel pump drive"

Also known as F1FA9D370GA - which is the number that is printed on the actual part

if that's at fault
Can be had for as little as £15 used - £64 from ford.

all the best.mark

[metalworker0]

oh check this out

he may be young .. but turns out to be a very clever knowledgeable guy, its a custom, but exact same set up as mk8

https://www.youtube.com/watch?v=qNfPEckzk6Y

all the best.mark

[shogran]

Thanks for those replies Mark, greatly appreciated!

I've found the module on eBay and definitely worth a punt before going down the route of replacing the whole in tank pump/sender. I'll watch that video after work too and see if I can gleam anything from that.

[metalworker0]

outcome in the vid is costly - replacing all injectors .. so do the cheap things first.

all the best.mark

[shogran]

Definitely will, interesting video! I'll see if I can find a leak tester kit, look to be a few on the ebay. Thankfully the injectors are still under warranty if any issues, would be just my luck that a new injector is borked! Will check that pump module first though and work from there

[Airthies]

Without reading the short story replies above, it Sounds like fuel draining back.
When it sits for a while a "soft seal" (one that seals under pressure but let's air in under vacuum) is letting air into the return/leak off side of the fuel system.

I'd reckon if in the morning you jump in the van, turn ignition on and wait 30 seconds then try and start it'll fire up pretty much straight away.



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[shogran]

Without reading the short story replies above, it Sounds like fuel draining back.
When it sits for a while a "soft seal" (one that seals under pressure but let's air in under vacuum) is letting air into the return/leak off side of the fuel system.

I'd reckon if in the morning you jump in the van, turn ignition on and wait 30 seconds then try and start it'll fire up pretty much straight away.



Sent from my Pixel 8a using Tapatalk

I did see some posts online suggesting to try this in order to prime the fuel system. I've tried a few times, and it seems to be hit and miss if it makes a difference (hard to tell as somedays it turns over for around 5 seconds and others for 20).

I've definitely cycled it a few times waiting 30 seconds between, like when you change the fuel filter, and it definitely wasn't an instantaneous start. I'll double check the leak off connectors on the injectors though to make sure they're seated properly and orings look okay