No idle stall after installing supercharger

Hello fellow tundra enthusiast,

I am at this moment typing to you from an autozone parking lot in the dark with a headlamp, laptop, and portable wifi hotspot internet from my phone. I am currently waiting for a tow truck to tow my 2019 Tundra TRD pro home as it is not running to even get me home. So i need your help just to see what I can do to fix this adventure im having. I just installed my harrop supercharger today with my friends who have mild to no mechanical experience. After installing the supercharger and installing the stage 2 tune for it I am having misfire in 1, 2, ,. and four. It started up okay but has extremely rough idle and died/stalled when I stepped on the gas. I am also getting "trailer brake error and pre collision system malfunction" on the dash but not a code.. We thought it was a fuel injector issues so we removed all the fuel injectors and found some injectors that werent seated in the rail all the way so I also on top of that had a too lean code. After clearing the codes it seemed to hold idle and i was able to drive it with extreme hesitation on the throttle to an autozone and nappa. After purchasing a battery and coming back the truck is havig trouble starting, holding idle, and missfiring again. Putting it in gear and then after touching the throttle completely stalls the truck. I've been diagnosing the truck and the unplugging the fuel lines from the fuel rails and front of the gas tank. Whats strange is that Fuel only comes out when im cranking the vehicle. No fuel comes when the Key is in the Ignition position. Same with the fuel lines on the bottom of the truck coming from the tank. In fact the smaller fuel line(which i presume is the fuel return line) I can crank and no fuel returns back to the tank. Only the fuel sending line has fuel come out when cranking. Is this normal behavior? I am convinced it is some sort of fuel issue. Maybe we got some hoses from the gas tank or fuel pumps mixed up or the fuel pump is dying. Please any and all help will be appreciated. I am in Valdosta, GA if anyone has the expertise please reach out to me. What are my options? Will the toyota dealership here touch it even if i did the modifications myself?

Update: after waiting 40 minutes I tried again and now the truck is holding idle but running rough. It also smells rich i think.

Sincerely,
Michael

 

Some harrop kits have the high flow fuel pump included. Did yours?

 

Yes it came with it but it was not under my supervision when I installed it so I’m not too sure if it was installed correctly

 

What’s the deal with the tune? Who provided it? It sounds like it wasn’t tuned in person by anyone, but you flashed a file at home? When I went to stage 2 my first couple tune files were basically just to get it running and get some logs and send them to the tuner to get it dialed in. It had to be driven super easy for the first few files.

 

It was d3performance.net

Texas has his tune running fine . I think it was installation error on our part

 

I don’t know how the D3 tune flashing works, but I’d assume it must be similar to HPtuners. Did you have a battery charger on the battery charging it when you flashed it, and then Unhook the negative terminal for 5 minutes before starting it? And you said you weren’t present for the fuel pump install, Who installed it? If in doubt to rule out the tune issue and check mechanicals you could swap the stock injectors and 85mm pulley back on and then flash the stock tune back and see if it runs fine on stage 1. I ran mine on stage 1 first for a while partially to make sure everything was working properly mechanical wise, so if I had issues I didn’t have to question if it was mechanical or tune related.

 

Also, on these trucks I don’t believe the fuel pump runs unless the truck is cranking or actually running. It does not prime the fuel lines ahead of time on key ON or anything was my understanding when researching previously but I could be wrong.

Edit: I double checked on this, and the pump does not run until it’s cranking (sees RPM). The fuel pump should have a check valve that holds pressure between the pump and the FPR/injectors. Unless one of them is bleeding the pressure out on the off cycle, the pressure should be maintained between startups.

 

Thank you so much for your helpful replies. Yeah I had a battery charger on the truck while flashing. Did not disconnect the battery though after the flash though. Fuel pump was installed from a friend who had the instructions up in his face while dropping the tank and swapping the fuel pump. Is it normal for the fuel return line(smaller line) to not return any fuel. I had the truck barely idling and there was no fuel returning on the return side.

 

Yes it did. Im thinking it isnt the fuel pump since im getting fuel pressure at the rails.

 

I guess I'd assume that the tune is fine if it came from D3, though if you have a way to flash the stock tune back so you have that as a baseline that wouldn't hurt. Your issues dont sound like tune issues though. From everything you're saying it makes sense that it's a fueling issue, you're getting misfire from no fuel flow. Every return style fuel system I've played with has a constant stream in the return line ESPECIALLY at idle since no fuel is being used relatively.

Is there an aftermarket fuel filter installed? Is there a hose from the tank that possibly got kicked? I'm wondering if the pump was installed and the integrated filter is either fucked up, or a cap got left somewhere so it's not sucking enough fuel. If you can hook up a fuel pressure gauge that'd be the best bet, though not sure if there's an easy way to do that on our engines. The lack of return sounds wrong to me though.

 

Yeahh exactly what i was thinking. There was an aftermarket tiny fuel filter included in the harrop kit i think. Ill drop the tank monday and see if im missing something.

 

That's where I would start too. I would also start the truck before you reinstall the tank to verify that it's functioning correctly with the tank laying on the ground. I would probably disconnect the pressure line from the tank, and hook a hose from the tank into a Jerry can so you can see the stream is steady and isolate the tank from the rest of the system. Sadly I have lots of fuel system troubleshooting experience and it almost always comes down to moving down the line one component at a time to find the issue. Luckily the stock tank is pretty easy to drop and the pump assembly is easy to pull out and can be bench tested and inspected easily.