K3 swap Cuore L701 engine cut after full throtle

Hi guys,

I am running into a problem and don´t where to look at first.
My K3 swapped cuore is running good, but has a little bug in it.

I was running an uphill section of the track full throttle with around 6000rpm (4th gear) for lets say 1 1/2 minutes.
In the following curner I drop into 3rd, take the curner and want to accelerate again. And this is where the problem starts.

The engine is dead once I put my food back on the throttle. It feels like the ignition got switched off.
So I am getting slower and slower and tap the gas a couple times. Eventually the engine comes back to life.
If I start reving the engine to the redline once it got back to life, there comes another cut out and its dead. So the tapping on the throttle begins again.
If I keep drining in low RPM´s once ist on again, I drove 30 seconds slow, then fullthrottle again and no issues.

I had this problem always at the same corner, after a long long straight. When I changed in the uphill section into 5th gear, I got slower because of uphill, but the rpm´s were lower obviously and I didn´t run into this cut out issue.

So has anybody got a clue what this is all about?
First I thought maybe the fuel tank is too low on fuel. But same issue with full tank.

Should I start looking into the fuel system? Pump, Filter…?
Or does this sound like an ignition problem? I guess the engine gets extremly ho t at this point of the track, due to the long stress on it.
Temp gage for water stays in the middle, oil temp is around 90-95°C.

If you need more information about the car or so, let me know.

Any ideas?

Thanks alot!

Are you running an external surge tank at all? Almost sounds like a fuel pump issue

30 seconds to recover? How long is one lap? That seems like a long time to recover fuel pressure.
Possibly coil if it’s the most loaded part of the track but not for 30 seconds.
As suggested by momeman I’d also look as serge but still seems a long time to recover.
How is the regulator?
No cuts in MAP line?
Is the engine light coming on during this?
Can you hear pinging or pre ignition during this power loss or temporarily before it?
Kinda does sound like fuel pressure loss…

Nope, its stock.

Not sure if the car is running stock EJDE pump or switched to the k3.
But if I would have to guess, i would say its k3.

Lap is 21km. Takes around 10 minutes.

30 seconds till its back to normal. Within this time I only drive in low rpm. As its still uphill I don´t want to get stranded. Thats why I play it safe and wait 30 seconds. Might be possible that its shorter.
But as I said, when the engines comes back after the first time its not enough time to wait 1 sec and rev it to max again. It will die then.

Engine light is on all the time even before this issue. I think its because of a missing rpm signal (due to the swap). But I don´t have the chance to check while I´m on track.

Can´t hear anything because its way to loud in the car while driving at this speed.

Thought about fuel pressure too.

So no one is thinking about ignition problems or temp?

maybe look at a good aftermarket fuel pump, or set up a surge tank with a seperate pump. pretty sure there is no difference between EJ & K3 pumps, my guess is it’s getting too hot at full throttle for the length of time then takes that little bit to cool down and work properly again, this is just a guestimate.

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I think Dale was pretty close to the money. Either way a surge tank with a high-pressure pump probably wouldn’t be a bad idea anyway.
If you have let’s say a 2l surge tank with high-pressure pump like Bosch 044 or similar you would have plenty of pressure and could run the factory pump and return from surge tank to feed the Bosch. It will have enough flow to keep the surge full and the Bosch won’t run it out if you have a return into the surge tank as well.
To fill the surge you don’t need pressure just flow.

Here’s a pic of the setup in one of my L200s


Your setup is looking great.
I think it won´t be doable in germany due to TÜV regulations. Not allowed to change such things when you are running the car on the street.

Are there upgrade pumps available for Daihatsu´s? So that I upgrate the fuelpump in the tank to minimize this issue? Or don´t you think that this will help?

Look at a Walbro pump

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XGSS342 walbro (255lph) should be fine as Dale said.
In Australia my setup is also not legal but hey… :stuck_out_tongue:
I’m sure that walbro in-tank will nearly directly plug in to your original pick up.
If not you will be able to make it work. Your very crafty.
Just measure the height of the pick up before you pull the original apart to make sure it works exact like original.
I used to use one on my starlet on e85 and keeps up with 560cc injectors before I went to the 460lph.
(I only changed pump because I went to 1100cc injectors)
The 255 is a good thing.

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Definate fuel pump clean tank and look at crank angle sensor plays up when hot

Definitly have to investigate this.

I will try to get the hood air out of the engine area under the hood.
Upgrade fuel pump would be the easiest fix for me.

I will try to have an OBD Scan tool on hand the next time the engine light comes on. I have to take care of this issue too. I want this thing to work correctly.

Here the latest run:

I will be on my next trackday on Saturday on a very tiny track.


pretty sure there is no difference between EJ & K3 pumps


yep, really, seem to be a generic type pump from the few i have seen and also the same as what was in my HC powered charade. in all reality the engines are only 300cc higher so wouldn’t use much extra fuel per hour

hmm interesting!
I’ve had a it of a look at them as well - they’re a common look for sure
I haven’t had them tested for flow or found the specs on them

But I have found that a k3 converted L7 has this problem - which seems to be fixed by converting the pump
And that the part numbers are different?

Also that in all honesty I haven’t compared pumps before by the cc of engine they delivered to
More likely to hp engine
Otherwise you could get into thinking that a detomaso pump could deliver to a modern f1 engine, cause they’re both 1600cc?

But I haven’t looked into OE fuel pressures either - or injector comparisons = if that all contributes to it

Otherwise the ejde is what? half the hp?

As far as this topic goes - my vote is on the pump swap required

The pump housing and connection points are surely the same (because they’re directly interchangeable) but that says nothing about the pump itself. Given that the fuel pump assemblies from each car have different part numbers, I’d hazard a guess that the flows are different between the EJ and K3 (also between the K3-VE(2) and the K3-VET)

I also have not tested them, nor have I found tech data on them in any manual, so this is just my deductive $0.02

I am trying to get away the heat from the Engine bay with lifting the bonnet a little.
I didnt run into this issue again. But I haven’t been at the same track again so far.
So Time will Tell. Of the problem remains, I will upgrade the pump