vegascoug

Okay, so my 1990 4-Runner has been bogging down lately, getting only 10 MPG around town, and just not running that strong. I used some of the Lucas fuel additive as suggested by the guy at Schucks. About 1/4 tank in to this treatment, my power came back (in a big way) but I don't know about the fuel MPG yet.

I went to the store yesterday, came back, parked it, went to get in it later and it smelled like I left a gas can in my rig. Fresh fuel and REALLY strong. I drove it and that's when I noticed the pick-up in speed, my V6 is running like a V6 again, but why the fuel smell. I have opened the hood to see if I can see any leaking gas, but I can't. I do smell it stronger up near the top, near the fuel injection, and it's almost unbearable inside my truck.

I am happy for the power, but I am curious to know if any of you master jedi on here (Yota) know where I could even start to check this out. I don't want to smell like I work at a gas station (not that it's a bad job) when I ride in my truck.

However I don't even know where to begin. My only thought was that fuel was building up somewhere because of a clogged injector or something, and now that this fuel additive/cleaner has started to work, it's flowing again and getting too much. My truck also starts weird, turns over more than it used to, maybe getting too much fuel.

Any help would be appreciated!

regularguy412

Check the pulsator on the fuel rail. I found mine to be cracked and leaking AFTER getting the fuel pump replaced. The smell inside the cab was so bad I could barely drive it.

Mike in AR

vegascoug

Ignorance is bliss, and I am quite blissful.

Where in the heck is the pulsator and fuel rail?

Mine is geting close to that.

Sorry for sounding stupid, but without my dad's help I can barely change the oil (not that bad really, but close)

Mike in OR

Elton

have you check the charcoal canister

Elvota

I beleive the pulsator is on the firewall end of the PS fuel rail. Will be hard to see, as it is basically under the intake.

mt_goat

This may help some:http://personal.utulsa.edu/~nathan-buchanan/93fsm/

singlo

Had same issue.

I took it to the Mechanic to do the overhaul of the engine since it was leaking oil as well. His conclusion was that the seal around the Fuel Injectors were leaking.

He fixed it and no more Gas smell in the cab.

For what it's worth, I paid $1,200 to fix the oil leak, water pump issue, Injector Seal replacement and brakes on all four wheels. So not sure how much that Injector repair was by itself.

regularguy412

The repair for my pulsator cost about $100 at a local shop. That was a little over 2 years ago.

Mike in AR

vegascoug

Does anyone know where I can find a picture of where the pulsator is? I am completely lost. Is it connected to the fuel pump? Easy to access? Anyone?

Sorry, but that seems to be the cheapest place to start, so I'd like to do that. The charcoal canister is $276 to purchase.

Mike

vegascoug

Is the pulsator in the gas tank?

mt_goat

No, the fuel pump is though.

I suggest you look though that link I posted, go to the "engine" section and then down to "3VZ-E", then look at the whole "MFI system". That is a FSM for a 93 truck but the 90 is almost exactly the same.

vegascoug

I've looked through that document several times, I must just be an idiot because I don't see anything on any of those pages that says pulsator.

I'll keep checking, thanks anyway.

regularguy412

May also be called a Fuel Pressure Regulator. When each injector fires, it causes the stream in the fuel supply to surge. The 'pulsator' or Fuel Pressure Regulator helps take the surging out of the fuel supply and lets the injectors deliver an adequate supply of fuel. Try this page of the FSM:

http://personal.utulsa.edu/~nathan-b...89fuelpres.pdf

As you can see, it's located UNDER the plenum on a 3.0.

Mike in AR

mt_goat

Yeah I don't know what a pulsator is, I thought maybe it was what the FSM calls a pulsation damper.

vegascoug

Okay, I found that earlier and wondered if that's what it was. I know where that is, so I'll check the area for gas.

Tough to see in my garage, I'll have to use my lighter (kidding)

regularguy412

Yes. I know it's tough seeing in there. I knew there was a leak, but couldn't seem to find it. That's when I gave up and took it to my mechanic. That was BEFORE I found these boards on the net and didn't have access to the FSM.

Mike in AR

vegascoug

I'll have to keep checking, thanks for the tips

vegascoug

I think it's because my fresh air intake, or air intake tube, is cracked severly. That is causing the air intake sensor (or whatever it's called, the thing that tells the engine how much gas to use vs. the amount of air coming in) to add too much fuel to the system because there was too much air coming in. I have sort of fixed it until I get a new one, and it's still not great but I don't smell the fuel as much and my truck starts much easier now.

regularguy412

Actually if you have a vacuum leak, the AFM won't know it. Therefore, the engine will be running lean.

When you fill-up with fuel, do you top off the tank as full as you can fill it? If you do, some of the liquid fuel may be running down the evap cannister line and into the evap cannister mounted on the firewall.

Mike in AR

vegascoug

No, it's not overfilling because this didn't start until I was about half a tank in...not really sure why it's happening.