Can Diesel Light off in a Modern HPCR: GDI Engine?

[Darkbloodmon]

Last tow of the night for AAA was a 2022 Toyota Highlander that had only 13K and was filled with Diesel.

Vehicle wasn't started but the I'm almost positive the Push start on/acc mode primes the fuel system. Needed that to get it into neutral and get the electronic E-brake off. Fun fact on the E-E-Brake. It has a weight sensor and won't go off until it feels a but in the seat with brake pedal pressure applied as a roll away safety feature.

This was a cash call off the street and looking to be a $93 tow for 4 miles to get it home at commercial rate. Back and forth ensued over not wanting to pay and just wanting to have it moved from the pump to a parking space for "free" so that their "Mechanic" could "Look" at it. To which I replied "Sure... I'll move it for free too a space but QT is not going to let you drop or drain a tank here in their lot, this needs to go to the dealership". They go back and forth with each other until someone produces a card and asks for it to be towed home.

Nothing much to towing it, get to their house and drop it in front of the double door garage. But all the while im thinking what their mechanic could possibly do.

I assume they're going to attempt to pump the fuel out, put gasoline in and repeat till they think its good. I forget if gasoline or diesel is the heavier fuel.... if the fuel pump is in a sending unit bucket with anti drain back valves there won't be away to remove the contaminated fuel no matter which settles on top or bottom.

Diesel is inside the fuel system. Period. But will the HPCR: GDI engine fire off it and run? These 4 banger engines are higher compression, with direct injection atomization. The engine should be a T24A-FTS 2.4L Turbo Multi Port GDI 4 banger since it wasn't AWD or a Hybrid.

Thoughts?

On a side note I also towed a 2017' Kia Sportage today with 82K and a locked up GDI engine with no oil, had warranty paperwork sitting in the driver seat ready for that engine replacement as I took it back to a KIA dealership.

 

[Ozymandias]

Don't see a big problem here, drain once, refill, crank.
Consider it a two stroke engine for some time. LOL

 

[Darkbloodmon]

Don't see a big problem here, drain once, refill, crank.
Consider it a two stroke engine for some time. LOL

I think it would light off a few times but the system would eventually put itself in limp mode or brick it from starting before it gets a chance to burn off the remaining diesel when it starts missing.

If it bricks its going to need dealership software/scan tools as new as it is.

 

[AH64ID]

What’s going to brick??

Diesel in gas is very different than gas in diesel.

On a gas motor there isn’t a return line, so priming the system when the key in turned to run doesn’t fill the lines with what’s in the tank it just adds a little fuel to get up to pressure. Drain the tank, fill it with gas and fire it. The diesel amount will be so low it’s not an issue and will remedy itself quickly.

 

[Darkbloodmon]

What’s going to brick??

Diesel in gas is very different than gas in diesel.

On a gas motor there isn’t a return line, so priming the system when the key in turned to run doesn’t fill the lines with what’s in the tank it just adds a little fuel to get up to pressure. Drain the tank, fill it with gas and fire it. The diesel amount will be so low it’s not an issue and will remedy itself quickly.

The engine's systems will brick is my guess because it'll sense an error in the fuel system when it tires to ignite the diesel. If I can't get the E-E-Brake off without weight in the seat and a foot on the pedal, the warning systems and dummy lights will scream when it figures out the injectors aren't spraying gasoline.

Is diesel heavier or lighter than gasoline? There is still the fuel in the sending unit bucket to be purged.

I know diesel in gas isn't as detrimental to the engine versus gas in diesel but I just don't think fuel contamination is going to be so easily remedied with a drain and fill.

As far as gas engines not having return lines back to the sending unit that varies by manufacturer and vehicle platform. A quick search on Rock auto looking at sending unit systems on recent model GDI engine platforms from GM (Ecotec), Kia/Hyundai(Gamma), Ford(Ecoboost), and Toyota/Lexus (M20, A25, and T24A engine families) Shows some with one line to a sending unit and others with several, item descriptions list the number of inlet and outlet ports as well.

The HighLander in question with the T24A is unknown, the previous generation utilized a single line sending unit on the inline four option.

I'll pop the question to a Technician at a Toyota dealership next time I drop off at one.

 

[Topzide]

It won't like the diesel fuel but it'll run, just rough for a bit! My son put 5 gallons of diesel in a 4 cly Caravan. It didn't like it at all but ran. I will say that once it all cleared, got some of the best fuel mileage ever! Drove like a pig! Was funny to see people looking for a diesel truck around with none in sight. That's what happens when you tell them to get gas and they know you have some at the house in cans!

 

[AH64ID]

Nothing will brick. It may throw a code, but that won’t brick it.

The remaining diesel will dilute with the fresh gas, even in the sending unit.

Not as big a deal as you think it will be.