On your potential fuel tank issues,, "While your there...."

Worst possible situation is a tank with "just a little gas".. Oxygen ruins gasoline, it turns in to something resembling varnish,
you want to store fuel tanks bone dry or full to the brim. Add Stabil when your going to leave one sit.

I would not try and dilute it , I would drop the tank, pull the pump assembly and clean the tank out..

Your pickup strainer could potentially be full of crud.. Also perfect time to check the rear tank hoses ,
there are a couple pieces of rubber line a the rear and they rot away, as well as the vent tubes for the charcoal canister.
If they get rotten they let crud in to the tank when your driving . If you deleted the canister under the master cylinder
and just plugged that little hose that was connected to it, your tank has NO vent to let fuel out so the tank will
develop a vacuum to where it can't get fuel.

You also have the square fuel pump assembly which in
my experience needs its gasket replaced about every 7 years.. It also rots and leaks fuel out or water and crud in.
Buy a good brand name one..

I've dropped my YJ tank multiple times, takes about 15 minutes to get the tank out after the first time.. Probably an hour the first time I did it.
7 bolts hold the skid plate up the tank bolts to the skid plate, two hoses behind the fuel filler , just pull the screws and you can push the filler inside the fender and undo the clamps.
Drop the tank passenger side first a couple inches so you can slide the filler neck of the tank from left to right to get the tank out.

If you have the plastic tank likely-hood of rust is zero, if you have the steel tank, the plastic one will replace it and give you more fuel capacity. (20+ gallons vs 15)
Your 19 gallon tank will hold between 20 and 22 gallons of you pull and shorten the tube out of the vent pipe on the fuel tank,
To meet fed regulations jeep installed a 8 to 10 inch tube in the vent that causes the gas pumps at stations to turn off and act like the tank is full.
You pull it out and cut it off so it only goes in to the tank about 1.5 inches inside.

 

Bad gas won't matter. Itll run, just run crappy. o2 sensors don't matter, itll still run without them, it just won't run as good as the computer won't get the feedback from the o2 sensors. The MAF doesn't matter as itll still run without it hooked up, it will just run horribly but itll run. Since youre running DBW my assumption is, check your throttle body. Common for those DBW throttle bodies to just become junk one day. Also, did you try crank sensor?

Pull the intake off and stick something in the throttle body to hold it open, then start it and see if anything changes.

 

Throttle body works. I can hear it and with the code scanner I have, it says it's working as well.

Should that be sufficient?

Looks like I'm going to change out the crank sensor as it seems to point in the directions of this.
​​​​​​intermittent starting. Rough running when it did run. I have to crank it for like 5 minutes on and off to get it started (when it did actually run) I think the injectors are just spraying trying to catch an intake valve open, and once it's turned over enough, there's enough gas fumes to run for a second. Or at least, it's finally found an open intake valve.

 

Well if it ran but ran rough i can't say its 100% crank sensor as all that does is send voltage to the coil packs to fire. So, if you know youre not getting spark now thats where i'd look. Other then that i would also check the cam sensor which is right by the oil pressure gauge right behind the intake on the back/top of the engine.

 

Maybe it was the cam sensor I was thinking. If the pcm can't find the cam signal, it will just spray fuel in pulses of hoping it will find an open intake valve. Anyone else have anything to add before I change it out?

 

Cam sensor unplugged will eventually run, crank sensor unplugged will never run, vats only lets the engine run for 2 seconds at most. I am going for cam timing, possible stuck injectors ( diagnosed by checking residual fuel
oreasure when key off) or faulty coil packs, or power to packs.

If all of h the plugs are black, then count out the last 2. What sort of injectors are these and how long have they been sitting around?

 

​​​​
using these injectors. The starting problem was there before I replaced the injectors. One of the originals was stuck, so I went and replaced them all after replacing just one didn't fix the problem. They have since been sitting for about 2 years.

I had to change the headers I bought and put on the LS3 Camaro manifolds due to fitment issues. The manifolds are black on the inside. Which means to me, it's getting fuel. A lot of fuel. Right?

 

Injectors from Amazon? That’s where I would start looking. Lots and lots of crap out there, it should run reasonably well without the maf, cam sensor, and o2 sensors plugged in. If all of the plugs are the same fouled rich black I would go there.

 

So originally when it ran it had factory injectors? One was stuck, and you replaced the factory ones with Amazon injectors? I have not been very lucky with eBay or injectors like that. Yes it is running very rich, and a quick plug reading on all plugs would be helpful to determine if it’s isolated or across the board rich.

 

It ran like it did in the YouTube video on the origional injectors... But it took approximately 5 minutes of on and off cranking to do that. Then when it died at the end of the video, it just died. I didn't turn it off. Those are genuine injectors that were rebuilt. I figured they would be okay.

I replaced my fuel pump because I had drilled a hole in the top for the fuel tank pressure sensor, then realized it was a bad idea and I just had gas venting to the atmosphere. So I replaced the fuel pump setup with a Carter pump. Still didnt run, so I replaced it with a walbro 255l pump because I didn't think I was getting enough fuel to the rails.

 

I may have missed it, do you have spark?

 

I would think so since when I first start to crank the engine it fires on one or two cylinders then stops. Is there another way I can confirm that it continues after the initial couple pops?

Guess I could pull the fuel pump relay then see if I'm getting spark. Is there something like a noid light but for spark plugs?

Also, to trace it back, would it be beneficial to unplug the coil packs from the main harness and check that grounds are being sent from the pcm? I'm assuming they always have power in run and start, the pcm just sends grounds. Right?

 

Much easier to plug a spark chech device into the plug wire, or known good plug grounded to check spark.

Have you done a compression check? Maybe we are looking where the problem isn’t, there are lots of variables here since the engine has been taken apart and reassembled. A compression check with a good tool will give you lots of information and maybe needs to start at the simple things. In the end it will be something relatively simple, checking off the simple things will lead you in the right direction. Compression and spark should be checked. Intake manifold leaks, and cranking fuel pressure should be checked as well.

With problems like this I always revert to the simple things before looking into electrical issues. Once you have determined that the engine has good compression, good spark, and fuel to the rail, then yiu can go to the next step. What is the cam number you put in there.

 

I've done a compression check. Gotta look through my phone to find the slowmo videos. They range from 180 to 155. But I'll run through the videos to get per cylinder numbers.

 

Maybe taking out the fuel pump fuse and running it on starting fluid will tell if it’s a spark or mechanical issue. Not really outstanding to do on a new engine, but if it runs smoother then you can go to fuel. You should be able to get it to run indefinitely by spraying small amounts into the intake while it’s running. Please have a fire extinguisher present for possible backfires.

I could be wrong, but I’m leaning towards cam timing/,cam issue. What cam did you put in there?

 

I had similar getting my ford Cleveland running on a 0411 ecu , but not quite as drawn out - first thing I did was have the ecu check for vats delete which it was, it was only firing on one cylinder - bear in mind I had to make my Cleveland engine take a 24x reluctor and sensor and cam sensor

After vats was checked , started looking at the crank and cam sensor wiring , cam sensor has two types and are wired opposite to each other - your harness could be wrong

It's easy for a terminal to get pushed out of the plugs so check that

In the end for me it was that the crank sensor has to face the correct orientation, being you can't rotate it in any other position other than the plug facing forward - but that won't apply not you really

Also at some stage I think I had the cam sensor 180 out and it will not run with that not correct - I've heard they will but not from what I've seen and others have said with a bad cam sensor engine doesn't run - tow home job

Anyway good luck - crank cam sensor would be my pick just start checking it all cause you sound like you are going around in circles.cheers

 

Engine won't run with a bad cam sensor. Cam sensor is, in a sense, the distributor. Thats why when you said it ran horribly BUT ran i first assumed cam sensor keeping the timing out of wack.

 

All the cam sensor does is detect which part of the cycle the engine is on. THAT'S IT.
It WILL start on the second try as the ECU figures out between the compression and exhaust stroke, IF there is nothing else wrong anywhere.

 

This above, on one of the 996 Porsche swaps I did with a 1998 f body ls1, the cam sensor has a disconnect right by the throttle body only in the 98 harness. This bypass got unplugged, but the car would take longer to start, but when it started the ecu would adjust and it would run well. Took me a while to figure it out, but simply reconnecting the bypass made it start easier.

 

Well everyone, I bought a crank sensor and cam sensor this evening. I'm going to replace one at a time. Hopefully it's the first one I pick so I can take the other one back to AutoZone. Lol if I end up replacing both, so be it. If it's not those, it's undoubtedly a fuel problem, or I put the camshaft in wrong by a chain link or something. But it ran for at least 30 seconds twice. So I'm thinking the cam was lined up fine.

So fuel, cam sensor, or crank sensor. LETS ROLL!