2016 Club car ex40 EFI misfire when cold

[Marshman1]

Has anyone experienced a misfire when the engine is cold? As soon as it warms up it runs fine most of the time. I notice it more when the engine is cold for sure. I replaced the spark plug with the factory ngk plug. My cart is a 2016 Clubcm car with the subaru ex40 fuel injection motor.

[pinhi19]

Yep. My 2018 Onward (EX40) does it until it warms up. More of a backfire than a misfire. Not sure what the solution is?

[Cartmaster]

We have these engines in some our golf course machinery. It usually ends up being the injectors needing cleaning. New injectors are very hard to come by without paying for the whole injection system at around 1500- 2000 dollars, but you can find them on aliexpress in packs of four.

The part number for the Subaru injector is FBYCG50-500 and sold For a Subaru Legacy MK IV 2.0i AWD 2003-2009.

An Excerpt from my previous post regarding this issue.

I had to look at a Kubota RTV400 last week with exactly the same engine and problem. Did all the usual checks for fuel pressure etc and nothing was showing up as an obvious fault until I installed a Colortune plug and immediately I could see the engine was running lean. It started a bit sluggish, Idled perfectly but under load felt like it was running rich and popping and lacking power. But the Colortune was telling me otherwise. I was getting 38psi from the pump, so not a fuel pressure problem. I suspected a fault with the injector and went on line to find a replacement. DOH! nearly 2000 of your American dollars as you had to get the whole throttle body and ECU as a matched set. No way was i putting up with that, so off comes the throttle body, out comes the injector and rigged it back up to fuel line and wiring. Cranked the engine and only got a dribble of fuel from the injector. I rigged up a power supply to open the injector without pulsing and ran some carb cleaner through it and suddenly the cleaner was passing through easily. I sprayed through again via the nozzle and a lump of something shot out the top of the injector.
I then refitted the whole lot back on the engine and fired it up, took it for a test drive and it ran absolutely perfect. After delivering the machine back to site, I did some research and found the number on the injector matched up with a Subaru car part but no regular supply of the said part.

You will not find many suppliers that would stock this item, but I found them in China.

Since I first posted about this, I have found out more interesting information. The EFI engine is basically the same item as the carbureted EX40 engine and it looks like you can use the carb for this as a conversion to normally aspirated and remove the EFI parts. a minor modification to the throttle linkage and you would need to install a low pressure fuel pump using the existing pump wiring, and then either figure out taking the ECU out of the equation or ignore the diagnostic lamp as the ECU will not be getting feedback from the engine sensors. Another option appears to be that there is a supply of EX40 engines available that will bolt straight in and replace the EFI engine completely. Just need again to do a bit of wiring modification to use without the ECU. These engines are available from around 400 bucks.

Any of these options are do-able and way cheaper than an OEM repair at 2 grand!

To answer an earlier question. Fuel pump pressure should be around 36-37 PSI for the EFI pump setup.

If going with a carb conversion, the high pressure pump could probably be used with a pressure regulator installed in the fuel line to the carb, or maybe even a simple T connector with a return line to the tank.

[FloridaCart]

Great info Cartmaster....... Thanks for posting

[Cartmaster]

Just had a look on the American Amazon site and some selling there too. Just type in the part number.