I own a 1991 pickup. Its a 3.0 v6. One day i smelt gas around my truck. Looked around and couldnt find anything. I still cant. Its been a week now and every so often i smell gas again. Gas cap is on and tight. Also this is probably related to the problem and i think it might be an indicator to someone who knows more than i do. When i start my truck the first time it will crank forever but not start. Turn the key off and try again and it’ll always start the second time. If anyone could help it would be much appreciated!! Thank you in advance

 

It's leaking. Oh, you already knew that!

But where? If it's leaking in the engine compartment, it's warm enough in there to very quickly vaporize the fuel. You can smell it, but you can't see it. So take the heat out of the equation. With the engine cool, jumper Fp to B+ in the diagnostic connector; this forces the fuel pump to run with key-on. Now watch and wait. With the engine off, it's safe to put your hand in there. But gas is hard to feel, so use a brown paper towel (gas is so "clear" that I find it hard to see on a white paper towel. Go figure.) Don't skip the Fuel Pressure Damper at the back end of the right fuel rail. Mine leaked, and so has it for several others.

You don't say where you're from. In the rust belt, the top connections of fuel tanks can rust out, allowing the fuel vapors a way to escape without going through the evap. canister. If you park where it gets hot, the fuel vapors expanding in the tank may overwhelm a marginal evap canister, and you can smell it there (it may even condense in the evap and leak out the bottom, down in the wheel well.)

 

Different engine, but might be helpful. My 87 22RE had two issues with fuel smell. First was a leaky injector that caused strong fuel smell whether running or not. Sent all 4 in for clean and test and reinstalled them. A month later the charcoal canister went bad and caused a strong fuel smell at start up only. Replaced the canister with a used one from a 93 3.0 4Runner. I had a friend help me narrow down where the odor was strongest, then started a deeper search in that area. Tracking down the canister issue was more difficult because it only smelled after startup and once the engine is running, the fan circulating the air made it harder to pinpoint the source. Took a couple of startups to find it.

 

It is very common for the metal fuel lines at the tank and around the fuel filter to rust out and start leaking. The lines fail right where they come through the top plate. The lines are on top of the fuel tank and will be very hard to see. Its best to get a friend and unbolt the bed and take it off. Its much easier to do than it sounds. The bed is surprisingly light. The part that fails is the fuel pump bracket. The high pressure line has some sort of compression fitting at the tank that is an oddball size. As scope already said the fuel dampers on these all so a common leaking point.

 

Pull your spark plugs and check for a wet plug or one that smells of raw fuel.. This indicates a fuel injector that leaks.

There is also possible issues with the cold start system which relies on the temp sensors having good signals (clean grounds on coolant sensors)..

If you smell fuel after its sat for awhile and before you turn the key there are a few options which have been covered already such as leaks in the tank/lines, the pulse damper, and the charcoal canister..

Fuel leaks are a very serious issue, remember it's not just your life you put at risk but first responder's and fellow motorists. Trust me when I say you never ever want to encounter an engine fire due to a fuel leak or electrical fire. Figure out what where and why or park the vehicle until.you can.

...

Is there a UV dye that works with the fuel system?

 

Thank you guys for the feedback. I found my problem. For me it is a hole in one of the lines on the top of the tank. Spraying a slight mist out of the smallest little hole. Truck is going down for repairs

 

Thanks for the report. So often, someone asks for advice, and we never know if the advice was any good at all!

Let us know how it turns out. Repair it yourself? What parts, and please take pictures. Having a pro do it? Same questions, but if you're willing, feel free to share the cost.

 

Actually i could use some more help. Has anyone ever ordered a fuel tank/pump assembly? I cant see as of right now which line is leaking. All i know is there is a fine mist coming from above my fuel tank so im guessing its a small hole in the line just a few inches above the tank. Just from seeing the mist, it seems as if its coming from a tad bit higher than the tank itself. My question now is, does anyone know if the fuel tank cap come with the 3 lines i see on diagrams online? Or are the lines separate. When i click on the parts and look at the diagram it has 3 lines coming out but in the description it doesnt say anything about the lines. It just has the titled part “fuel tank cap” “fuel pump” or “fuel tank/pump assembly” im 90% sure the line is where the hole is. But i plan to take the bed off to get to it because my truck is so high and i know theres a hard line if not more and i dont want to brake a whole line just from trying to drop the tank a little to get to it. I just thought that if i can get more info now, i can order parts so by the time i get the bed off i can start repairs right away. Im going to be doing this repair myself with a friend and my dad. Ive done everything myself all the way on my build so im confident i can do this. Thanks again for the help and once i start i’ll be sure to take pictures and keep you all updated for people who need the help in the future. Thank you for the help once again

 

I've never ordered that part, but the diagram here https://parts.lakelandtoyota.com/sho...rimLevel=18380 looks pretty clear. I think you're talking about the Bracket, Fuel pump . If I knew that was the part I needed, I'd place a phone call to a dealer with my VIN number to figure out which one is the correct one.

But that part is north of $150, and you don't know if that is what you need. Like the rest of us, you'd like to have all the parts (and just the parts) you need before you pick up a wrench. Alas, it just doesn't work that way. If you've rusted through a fuel line (and you don't even know that yet), you may have a lot of other parts rusted through. I'd recommend you get the bed off so you can see what you're working on, then remove the parts you need to replace to confirm you can remove them without breaking something else.

 

If you have a fuel mist than it's the high pressure line. All three lines are part of the fuel pump bracket which is the part you need. It is expensive from toyota. I put one in my moms 94 4runner. It is possible the repair the one you have using epoxy. Where the line goes through the plate it's just soldered or welded but it will come right apart with the amount of rust that's on it. Buy a new metal line from the auto parts store to replace the existing one that is rusted out. Use epoxy to seal where the line goes through the top plate. It seems like a hack fix but that bracket is just a piece of metal with three lines going through it. The screws that hold it to the tank may be rusted to hell. If the current pump is of unknown age now is a great time to install a new denso pump.

 

Update: Me and my pops finally had the time to get a closer look today!

We decided we wanted to drop the tank just a little so maybe we could pin point where exactly this mist was coming from. Not knowing what to expect we first unhooked the negative at the battery just in case, unscrewed the fuel filler spout, and then we took our floor jack and put it on two 4x6 blocks to get more height and then used a 2x6 on the jack's head itself to cover more surface area of the fuel tank. We unbolted the shield first and then the brackets that hold up the tank itself and slowly (VERY SLOWLY) started to release the jack and let the tank come down. Maybe 3 inches down we could just start to see the connections on the fuel pump bracket (which is what we were going for). We noticed that there were no hard lines other than the bracket itself. So we decided to drop the tank way lower, while watching everything very closely making sure not to break anything, so we can fully see everything. We couldn't quite see exactly where the hole was so we hooked the negative back up to the battery and gave her a quick turn of the key and then shut off (it was instant) to let the fuel run and see exactly where the hole was. FOUND IT! On the bracket there were two hard line coming off from it. So right then and there we knew we needed a new fuel pump bracket. However, my fuel tank was filthy and we decided since its so far down already, why don't we just drop it all the way out to check if the tank is still good so we can order a new tank all together if we find bad rust spots. So we dropped the tank all the way out, took a wire brush to the hard line with the hole to see if we could just clean it up a bit and possibly patch it temporarily because I also daily drive my truck. Found out that it was literally rusted out and actually the rust was the only thing holding it together. It ended up just snapped right off and we didn't go hard with the wire brush either so that was a wow moment. Its not pictured, but we cleaned up the tank and there's actually a few dime sized rust spots on the tank that aren't horrible but skeptical because they go deeper than the rest of the tank but also around the sending unit cap and the fuel pump bracket the necks that the gasket sit on were pretty rusty. I decided to go with a new tank just to be safe. Also if you look at that free dangling wire, that's the ground! it wasn't ever connected and my pump was still working. Thought that was pretty weird. So my truck is currently sitting in the driveway without a fuel tank and the parts search has begun. Finding everything easy but shipping to Hawaii is a nasty deduct outta the bank too so just seeing where is better on shipping.

I wanted to thank all of you again and this is my first time posting pics and an update so bare with me please. Install update to come. Wish me luck

 

Remove the fuel pump bracket and pump from the tank and you will see what I mean by repairing the existing tubes. I want to say from the factory the steel pipe is just brazed to the top plate. It would be a fast repair for now while you track down a new tank and bracket assembly. The underside of your truck is amazingly clean by the way. I am surprised that the bracket rusted out like that. Its very common to see on the East coast.