travisamorgan

My 94 pickup with a swapped 99 4runner 3.4 has started finally. I got a new problem. I had the truck running for about qn hour total off and on as I did my wiring and while trying to figure out which gauges were not working and some other little kinks and odds and ends. I quit for the day and went back the next day and restarted the truck to actually let it finally warm up and see which codes would set.

I walked away to my other car and when I turned around it idled down and I looked over the cab and fuel was spraying all over the driver side. I shut the truck off and looked at my return line and saw a hole. When I installed the engine I didnt switch the fuel lines around to the passenger side because I originally was going to move fuel lines around to the driver side to avoid switching the crossover around. Decided against it since the fuel tank would have to be moved. Anyways I forgot to switch around the lines. So I ran the fuel lines up along the firewall like the vacuum line for the brake booster was routed. I used hardline for the feed line from the tank and used fuel injection hose from advance all the way across for the return line.

The return line has started to give me problems it swells up and the line gets a hole in it like it cant hold the pressure. I have tried to put hard line in places and used some short lengths of hose and some other combinations. It blows a hole in the fuel injection hose every time.

It should be lower pressure right? The feed line has had no problems. The truck for a while with no problems so I doubt it has any plug problems. Any advice on whats causing it? Air bubble shouldnt cause an issue since it worked before.

Im gonna move my feed and return lines to the driver side tomorrow but dont want to still have this problem. Its 3/8 and 1/4s inner diameter hose and hard line (I have both).

Any advice or ideas?

JasonYota

iTrader: (1)

Did you flip the fuel lines to the passenger side? Is there a blockage in the return line between the engine and the tank causing it to bust?

travisamorgan

Yes I will and would it just randomly develop a blockage overnight?

Any easy way to check the return line on the truck? Just blow air through it?

Terrys87

iTrader: (1)

I have seen the "J" line clogged numerous times. If it is clogged, most likely the return line is clogged also. I remove the gas cap and using low pressure air, check to see if it is clear. Using high pressure air could compact a clog and make it worse to clear. I soak the line in PB Blaster or Marvel Mystery Oil for a few days at a time. I use a gear oil bottle lid as a funnel to fill the line up.

wyoming9

iTrader: (1)

Sounds like you got a really bad lot of fuel line.

Or the clueless person at advanced auto gave you the wrong line

last I bought Fuel Injection Line it was around $7.00 a foot.

Is that close to what you paid

travisamorgan

It said electronic fuel injection hose right on the hose. I have a friend that works at advance so I got his discount so not sure what I paid.

We changed it around again and nothing blew so I guess its running right. Ill hook a scan tool up to see if its running rich or lean.

4x4runr

Check your vent line also, there should be no to low pressure from the return line unless the vent line is clogged. The feed line would not (normally) blow because it's a high pressure hose/line. Anyway, glad its running!

travisamorgan

I re-ran the line and I got it to stop bursting. Anyway to test the fuel regulator? There seems to be a lot of pressure in the return line still.

the vent line seems to be unclogged fron what I can tell.

wyoming9

iTrader: (1)

You are running the stock fuel pump ?

You didn`t do some upgrade to keep up with the neighbors ???

Cause any excess fuel is going back the return line.

travisamorgan

Nope stock pump and stock 3.4 99 4runner ecu and engine and injectors. And fuel rail. And fuel regulator. All stock. I got it to stop bursting. If I pull vacuum off the regulator it should make the pressure go up or down?

travisamorgan

ok new issue. we put about 15 miles on the truck driving back roads and interstate. when I got home I noticed the truck was surging at idle a little. I also noticed fluid on the driver side inner fender below where my evap canister is sitting. I opened the hood and the line from the fuel tank to the evap canister was leaking liquid fuel.


I thought the line from the tank would be only vapor? no liquid?


I did put $15 in gas into the tank right before the drive.


whats wrong? I hooked it up like elvota's swap. any ideas?

rworegon

Can you post up some pictures of your set-up?

Also, it may help if you put your location into your profile as there may be a member nearby who may be willing to take a quick look at it for you.

travisamorgan

I have it set up just like this link: https://www.yotatech.com/forums/f2/e.../#post50681878


I have it routed just like it says it should be. I have liquid fuel under pressure coming out of port #2 in the 5th post of the thread.

SacRunner

I'm certainly no expert, but I have dropped my gas tank a couple of times now and there are 2 small (1/4" maybe) lines that go between the hard lines on the body and the tank, one is the evap vent line that goes up to the charcoal canister, the other is the fuel return line, maybe these got swapped at some point in time?

I've also heard that if you get these two lines mixed up (typically in reference to a mix-up under the hood vs. back by the tank) you'll end up filling the charcoal canister with fuel, which sounds like what's happening to you.

I'd go through and physically trace (like with a marker, grease pen/pencil, or some other means that you're able to verify 100% that you don't accidentally mix them up) the hoses all the way from the tank, to the fuel rail, back to the tank, and again for the evap system.

travisamorgan

Ok ill retrace them again. I didnt touch any line from the fuel filter back to the tank and the truck ran with the 3.0 so I doubt they are wrong.

At work when I left I noticed I had fuel on the ground by the evap canister side. I had liquid fuel coming out of the vent hole on the canister. And a lot of pressure was in the tank when I opened the fuel cap. The truck was also jerking a lot while driving and once stalled at a stop. The jerking maybe clutch related or driveline tho.

What would cause that much build up of pressure to cone out if the vent line?

travisamorgan

Ok I checked and I had them hooked up right. I had codes for evap stuff but deleted them and they havent came back yet.

I know newer vwhicles have vent solenoids back by the tank to vent off pressure for the fuel. Does my truck have one or is it up on the evap canister from the 3.4? If its stuck closed itll trap lots of vapor pressure.

I also seem like im using a lot of fuel but im sure oxygen sensor could be at fault but ill look into it.

wyoming9

iTrader: (1)

Your using fuel because your dumping it on the ground.

$15.00 in gas is really very little these days.

Since you were blowing the return line apart now your pushing gas out of the charcoal canister.

Your engine seems to be running poorly !!

You say all the fuel lines are correct!!

It seems your still getting way to much pressure in the tank.

Just what EVAP codes did you have??

Sometimes it takes a good many miles for the EVAP test to run. So of course the MIL would have not yet come back on.

Something is very wrong but not being there in person who can say just what.

travisamorgan

I have a code for evap vent solenoid. I saw on the wire diagrams theres a wire that goes through ii2 connector on the 3.4 and I dont have it wired up. I havent really diagnosed it much since it quit leaking and the fuel lines stopped bursting and giving me problems. I guess any blockage was blew out and I ran some fuel cleaner through it and maybe cleaned it out. I am gonna look to see if I have to actually wire the wire to power sonewhere or if it is actually the problem with the solenoid or switch or wire between the two.

Thats my weekend project. I have a scanguage2 hooked up and it says at roughly 70 according to gps its using about 2.7 to 3.2 gallons of fuel oer hour which cones out to between 22 and 26 mpg roughly but it depends on wind and road layout so just a guestimate. I am also gonna try to figure out my speedo for a more accurate mpg. It doesnt seem to be using much more fuel than my 3.0 did maybe a bit better but the motor sat for a while so jusy needs a tuneup and some runtime and should run better.

JasonYota

iTrader: (1)

Have you calibrated your scangauge? Mine took about 4 tanks of gas to get the readings smoothed out. The MPG, GPH, etc is calculated using logic based on your throttle position, speed and offset when you calibrate it.

travisamorgan

Well my speedo doesnt work right now and I don't have it wired up to the ecm so the scanguage says 0mph and 0mpg. The gallons per hour should be calculated from either a sensor on the fuel rail or the fuel pump.

Im gonna fix it or at least try to this weekend.