bennyt4130

Hi everyone! I don't post much here but yesterday something happened that has puzzled me so far and I was hoping some of the experts here might shed some light on my problem or link me to a thread that might help.

Here is the situation-

Truck sat for 4 years up until about 2 years ago. Motor is 3VZE with Auto. Gas tank and fuel system were contaminated with rust. Upon attempting to put her back on the road, the gas tank was dropped and rust treated. The fuel pump was replaced and the fuel filter was replaced. After some extended starting problems, the starter was rebuilt and the alternator was replaced. Those two repairs are probably unrelated but I figured I would be thorough.

The truck started and ran great for the last two years.

A couple of months ago, it occasionally started to bog down upon start-up and first minute or so of driving. I thought it was no big deal. Always worked itself out quickly.

Yesterday, I am pushing hard up a long hill in town and had the pedal to the metal. It downshifted twice and just after the second downshift, it lost full power and bogged down to about half torque as speed dropped. I got to the top of the hill and it got better momentarily. Within a half mile on level roads, it was running very rough and was losing even more torque. It finally stalled out. I tried starting it and it seemed like it was really wanting to start but just wouldn't quite fire up.

Here are the facts-
It got rained on real hard a few days ago with no top on and the windows down but I just don't think that is a factor because the truck started and drove perfectly yesterday before the trouble started.
It has gas but is low. Maybe 4 gallons right now.
I pulled the fuel pump. Pumping great.
Changed the fuel filter. Probably unnecessary in hind-site.
I pulled the fuel line at the FPR and turned the ignition. No gas was pumping at the time I inspected it.
I left and came back two hours later to tow it and it started normally. I drove it about 1 mile and it stalled dead. No sputtering or misfiring. Just died.

After the tow- I got it into my driveway and am now ready to do some surgery.

Here's a couple of questions-

Is there a good diagram of the fuel system here some where? I need the 1988 FSM but am having a little trouble locating one on here.

What components are located between the Fuel Filter and the FPR?

What could cause lack of fuel pressure even though the fuel pump is working perfectly and fuel filter is new?


Thanks very much for reading this and if you can help, you are a saint! This is my only working vehicle and my DD and I need this thing desperately.

Thanks to everyone! Cheers!

TNRabbit

I'm going to post my standard reply on threads like this:

HAVE YOU PULLED CODES YET?

The fuel rail & Fuel Pulsation Damper are the only things between filter & FPR. Neither of those should cause any of the trouble you're having.

Fuel won't pump with ignition on; it has to be cranking.

Link to FSMs is in my signature.

bennyt4130

Thank you. No, I have not pulled codes. Is there an easy way to do it without the little toyota tool? It was cranking. Fuel pumps from the pump but not at the FPR. Thanks again for the response and the link.

j2the-e

Maybe a clogged fuel line? There is also a hose on the pump that can deteriorate- especially when the fuel gets old. You can run the pump by installing a jumper wire in the diag connector under the hood. Connect B+ and FP

bennyt4130

I was thinking clogged fuel line. Gonna do some checking and blow out the lines.

j2the-e

Be sure to check that hose too. It connects the top of the pump to the metal line. I've seen it split where it looks ok, but won't hold pressure

scope103

The Toyota SST is no longer available. You must use this after-market tool: http://www.officemax.com/office-supp...oduct-ARS24645 (You probably aren't going to get a code, but gee-whiz, always, always check for them!)

You have a clogged fuel filter; either in the tank or the inline filter. Some crud broke loose in tank, and it got pushed at 75psi until it hit something that could stop it. When you changed the fuel filter you didn't flush the lines (usually not necessary, but if you've got a lot of crud in the fuel system it has to sit somewhere), and that crud got collected in the new filter.

As others have pointed out, the fuel pump does not run unless a) you are cranking, b) are running (powered through the VAF), or c) you jumper B+ to FP (the easy way). If you have jumpered, and you hear the pump running, and you get no flow on the low-pressure return from the FPR, then you've got a clog somewhere. Nothing is going to get stuck between the filter and the regulator at 75psi.

Of course, there is the possibility that you are getting fine flow to the regulator, and your crud has now gotten all the way to an injector. But first things first.

Good luck!

bennyt4130

Awesome. I really hope I don't have to replace the filter AGAIN but it is coming off to blow the lines out so perhaps. Thanks very much. There was TONS of crud in the tank when I rust treated it. I thought I got it all, but the lines were never flushed. Seems like your theory makes tons of sense. I will be working on this. Please check back for developments!!!

donomite49

heres fsm's,

https://www.yotatech.com/forums/f115...manual-156129/

idk, need to determine if it's fuel or electrical.

bennyt4130

I replaced that little section of hose a while back. Good info, though. Thanks.

donomite49

have you looked into the tank with a flashlight to see how it looks?
visually inspect the gas tank for rust/water after you blow out the gas lines.
i agree with other posters, i would suspect rust/water.

bennyt4130

I am about to do all of that.

Here's what just happened. Went out and started her up. Idled perfectly for about 5 minutes. I drove it around the block twice and it seemed like it was a little hesitant and under powered but otherwise running pretty well. I punched it and it bogged immediately but still ran a little. It stalled dead about 30 yards later. I bet when I go back to start it in about an hour it will start very nicely. Seems like some gas is getting through but when the throttle is punched, it clogs. As soon as I get it back over here, I am gonna start tracing the fuel lines and blowing out sections.

I am confused about one thing: Does the FPR control pressure on the feed or return line? Which one is it? I am gonna say return but I can't tell until I see a diagram.

Thanks again.

scope103

The FPR sits at the end of the fuel rail, and it "bleeds off" the input flow that exceeds the required pressure. So the return line is at (basically) atmospheric pressure, and the fuel rail is held about 50psi above the air pressure inside the intake manifold (which pressure goes up and down with the throttle opening).

This way, the amount of fuel "injected" is determined only by how long the injector is open, something easy for a computer to set.

donomite49

how bout water in the gas?

tried seafoam or chemtool (cheaper)?

bennyt4130

Stranded down the street right now.

bennyt4130

That is awesome. Thanks.
I'm gonna go ahead and drain the gas when I get it back over to my driveway. It's stuck down the street right now. Gonna go get some starting fluid in a few. The get it back in the driveway and check the gas. What is the tell tale sign? Cloudy gas? Milky kind of?

SeeBeeAre

if there is rust in the tank i got a neat trick on getting it out but it takes a couple days and it coats the tank with an anti rust surface.... (nothing to flake off or cause damage) PH+ (for spas), water , a large zink bolt and a 12 volt battery charger

bennyt4130

I forgot to mention that the preliminary filter on the fuel pump had zero rust sediment on it when I pulled it yesterday. I'm gonna be pulling it again in a few minutes.

I am gonna go with water in the gas right now. That makes the most sense of given all the factors. I'm hoping that is it.

scope103

Easy to test: put the fuel return from the FPR into a mayonnaise jar, run the fuel pump with Fp to B+, DO NOT SMOKE.

Water in gasoline looks like a big clear glob; you can't miss it.

Water is much heavier than gasoline, so it should be sitting in the bottom of the tank and get pumped out first. So I'd be surprised if you could ever get it to start. I suppose you might have cranked it through the fuel rail, got to enough gas to start, then the water recirculated and killed the engine after a few minutes.

But the test above will tell you, as long as you don't shake the truck so much that you mix up everything in the tank.

bennyt4130

Cool. Here's a little update. I got it back in the driveway and am about to check the codes and do that fuel test. Back in a few. I may just drain the tank because it has gotten a little shaken up in the last hour or so. Gonna pull the FP again also and look for water. I blew some air through the old filter and there was a TON of black stuff in there. It was certainly in need of a new filter. I am just gonna remove the new one and clean it well with fresh gas. The amount of sediment in the brand new filter should be telling.
Of course, I am also trying to get some painting done and finish building my fence. This came at a bad time.