'85 4Runner fuel system

[hinoranger]

looking for ideas on a possible fuel pump failure- several instances of reduced power- a "running out of gas" feeling several times in the last couple hundred miles, mainly while cornering or acceleration- and then complete shutdown just after pulling away from a stop sign yesterday.
Should I be able to hear the pump run with the key on? other thoughts?

Evan

[corax]

3 things to check:

Fuel Pump - check pressure, you may be able to hear the pump running and still have low pressure

Fuel Filter - possibly clogged - take it off & try to blow through it in the same direction as fuel flow, there should only be a slight restriction - if the fuel pump is bad, you'll want to replace this also, a restricted fuel filter makes the pump work harder & will lead to early pump death

Fuel Pump Relay - you should have close to battery voltage at the fuel pump (use a volt meter), less and the pump won't be able to work to capacity - if it's less, suspect resistance in the relay of the connectors

If it's intermittent and you don't have the tools for the above checks, I might consider replacing the fuel pump and filter

[Grim Reaper]

That first one is a FSM for a 85.
http://www.ncttora.com/fsm/

Corax has hit most of the common ones. Here is a few more.


Check the intake tube between the AFM and the throttle for any cracks.

The pump is pretty quite. Pull the passenger side seat bottom up and you might be able to hear it. You could remove the access plate to expose the top of the tank there as well.

Under the hood if you jumper the square plug with near the two round diagnostics plugs it will turn the pump on if the ignition is on. You can hear the fuel running past that dampener and fuel pressure regulator with the engine off.

http://www.4crawler.com/4x4/CheapTricks/index.shtml#TimingCheckConnector

Another thing to check would be the grounds for the injectors. If the upper plenum is removed the ground lug is often left off. It goes on one of the bolts between the 2-3plennum runners. you should see it standing by the passenger wheel. It will have three wires on it.

I have heard some complaints of the harness running to the fuel pump getting grounded out. Inspect it. It drops out under the passenger seat and runs back to the tank.


I have also heard of some instances of a bad bypass in the fuel pump sticking and dropping fuel pressure on the rail It is usually caused by a bad fuel pressure regulator holding excessive pressure (and I just changed the regulator on my 86 today to cure a poor idle and mid RPM mis).

Might be an ignition switch problem as well. Its not unheard of. Do you have any start probems where you have to keep hitting the key?
http://www.4crawler.com/4x4/CheapTricks/Starter.shtml#OtherOptions

[ntsqd]

An issue I've had on two 22RE's is the damper on the fuel rail. With age it leaks. Mostly this shows up as long cranking when warm and then irratic idle for a few moments after starting.

[DaveInDenver]

An issue I've had on two 22RE's is the damper on the fuel rail. With age it leaks. Mostly this shows up as long cranking when warm and then irratic idle for a few moments after starting.
You mean the fuel pressure regulator? What did you do to figure it out? It seems easy enough to diagnose if you have the SST fuel pressure tester, but I don't and it does not seem like a universal type will work. You are supposed to hook the gage to the cold start injector pipe on the fuel rail with the banjo bolt. Any recommendations on which tool to buy if not the SST?

[ntsqd]

No, damper is what I was told. I didn't figure it out. A trusted mechanic did on the first one, and the second is behaving exactly the same. I've not yet delved into it, so I'm not completely familiar with their function.

[Grim Reaper]

No, damper is what I was told. I didn't figure it out. A trusted mechanic did on the first one, and the second is behaving exactly the same. I've not yet delved into it, so I'm not completely familiar with their function.Dampers job it to keep the fuel from pulsing on the rail. The pump will not make a steady stream, it is bursts.

Well thats interesting. I had a Dampener leak and I swapped it out for a used one off a 7M a couple years ago. I am seeing a LOT of age related failure on parts right now. Rubber seal goofing it up, diaphragms cracking etc. Maybe I need to buy a new one.

I have a really hard start when warm issue going on. Starts great cold. It seems to have gotten worse now that I replaced the fuel pressure regulator but the regulator did fix a rough Idle problem and rich at low RPM problems and it allowed me to reconnect my EGR.

[DaveInDenver]

I understand what they do, it's just wasn't aware that the 22R-E had a fuel rail damper. My fuel pipe feeds from the front and has a pressure regulator with vacuum and fuel return hoses coming off of it in the back. Attached a few pictures of my engine, where do I need to be looking for a damper? I have a funky idle sometimes, too, and I want to check to see if mine is leaking. There is no mention of a damper in my FSM, so maybe it's a year dependent thing? The pressure regulator is original, although I have new one to install at some point when I get the time to tear into it.

[ntsqd]

I'm thinking that you're correct. That they are a year dependent thing. Those I've seen were first an '85 RE and now an '86 RTE (RET?).

EDIT:
Attached are pics of the damper. First is on an unkown vintage (suspected ~'90) intake for Patch's EFI conversion. Second is on the turbo truck.

[DaveInDenver]

Interesting (sorry for the thread jack to the O/P). Mine's a 10/90 production and did not have a pulse damper. But where you show yours, that does look like my fuel rail and the hose coming up from the fuel filter, but the book just calls for a banjo bolt in that location and the EPC does not list a pulse damper for my application. I'll have to look into this and see if I can find the part number from a 1990 and see if that settles down my idle surge and mid throttle hiccup. Of course the fuel pressure regulator will probably help that, too, but if I'm messing with the fuel rail I might as well consider both.

[Grim Reaper]

Interesting (sorry for the thread jack to the O/P). Mine's a 10/90 production and did not have a pulse damper. But where you show yours, that does look like my fuel rail and the hose coming up from the fuel filter, but the book just calls for a banjo bolt in that location and the EPC does not list a pulse damper for my application. I'll have to look into this and see if I can find the part number from a 1990 and see if that settles down my idle surge and mid throttle hiccup. Of course the fuel pressure regulator will probably help that, too, but if I'm messing with the fuel rail I might as well consider both.
That's what I was attempting to fix on mine and the regulator made a BIG difference.

Running with the back window down was not really an option in my 4Runner. I drove around most of the afternoon yesterday and hardly ever got a whiff of exhaust.

I wonder if the dampener got moved to the pump on the newer models or just totaly dropped? I would be curious if I could just order up a banjo Bolt and get rid of it.

What size wrench? I might swing by a junkyard near where I have to go tomorrow and see if I can find one.

[DaveInDenver]

That's what I was attempting to fix on mine and the regulator made a BIG difference.

Running with the back window down was not really an option in my 4Runner. I drove around most of the afternoon yesterday and hardly ever got a whiff of exhaust.

I wonder if the dampener got moved to the pump on the newer models or just totaly dropped? I would be curious if I could just order up a banjo Bolt and get rid of it.

What size wrench? I might swing by a junkyard near where I have to go tomorrow and see if I can find one.
Don't remember the wrench size, but it's fairly big. Probably at least 17mm and I want to say 19mm maybe. But I'm only guessing, I don't remember. I did torque them when I assembled the EFI, so that would have been a 3/8" socket and my biggest 3/8" is 19mm.

Checked my engine build notes. This is for a 10/90 production 22R-E. The front fuel line banjo bolt is 90401-14010 and the fuel pressure regulator is 23280-35030 (this is listed for 08/88 and up in the EPC). No pulse damper shown.

For an earlier 22R-E the fuel pressure regulator is still 23280-35030 and pulse damper is 23270-42010. This is 12/87-08/88 production.

The Aisin fuel pump for 08/88-08/91 is 23220-16084 and Nippondenso for 08/88-08/90 is 23220-16190. For earlier production (08/86-03/89) the fuel pump called out is also 23220-16190, apparently always the Nippondenso.

So it's weird that the same fuel pump is used from 1986 to at least 1991 and for certain applications there is a pulse damper and some other not. Obviously Toyota made a change in 08/88 to go to the bigger throttle body and plenum, so that might have something to do with it. The injectors are also not the same. For 12/87-08/88 injectors are 23209-35030, for 08/88-up they are 23209-35040 and so it could be a difference in injector design, too.

[hinoranger]

Hey guys-

thanks for the ideas and no worries on the threadjack. I put off jumping on the toyota pickup band wagon for a long time but finally had to come to terms with the fact that the Unimog/Rover/Syncro with engine conversion is going to be out of my budget for awhile, so any and all Toyota discussion is more than welcome.

Havn't had time to really work on it yet. It's parked on a side street in a ok neighborhood a mile or so from my place & I don't have a garage at home so mostly waiting for the temps to warm up (nice bright sunny day but it was 18 this morning).

[DaveInDenver]

Should I be able to hear the pump run with the key on? other thoughts?
This is not the case with a 22R-E. The pump does not run with the key, but rather it takes the engine to be sucking in air or the starter cranking to cause the pump to run. During cranking there is a bypass that turns on the pump with the starter and while running there is a switch in the AFM that keeps it going as long as air is being sucked in. There is no electrical switch on the fuel rail or anything, so it's sort of a secondary way to click the fuel pump relay. But it works. Grim's link to 4Crawler is good, Roger has lots of FSM pictures for a pre-1989 EFI system.

[Grim Reaper]

Don't remember the wrench size, but it's fairly big. Probably at least 17mm and I want to say 19mm maybe. But I'm only guessing, I don't remember. I did torque them when I assembled the EFI, so that would have been a 3/8" socket and my biggest 3/8" is 19mm.

Checked my engine build notes. This is for a 10/90 production 22R-E. The front fuel line banjo bolt is 90401-14010 and the fuel pressure regulator is 23280-35030 (this is listed for 08/88 and up in the EPC). No pulse damper shown.

For an earlier 22R-E the fuel pressure regulator is still 23280-35030 and pulse damper is 23270-42010. This is 12/87-08/88 production.

The Aisin fuel pump for 08/88-08/91 is 23220-16084 and Nippondenso for 08/88-08/90 is 23220-16190. For earlier production (08/86-03/89) the fuel pump called out is also 23220-16190, apparently always the Nippondenso.

So it's weird that the same fuel pump is used from 1986 to at least 1991 and for certain applications there is a pulse damper and some other not. Obviously Toyota made a change in 08/88 to go to the bigger throttle body and plenum, so that might have something to do with it. The injectors are also not the same. For 12/87-08/88 injectors are 23209-35030, for 08/88-up they are 23209-35040 and so it could be a difference in injector design, too.

I thought the injector change was just impedance but the time frame does make you wonder. I'm going to try it if I can find the banjo bolt.


Hino:

check the codes before you do anything to it. Link is on 4Crwalers site as well as that manual link I posted.

In KISS terms There is the injector timing signal wire that runs from the igniter over the valve cover to the main FI harness. They are really bad about getting on the hot exhaust manifold. Check that.

[hinoranger]

This is not the case with a 22R-E. The pump does not run with the key, but rather it takes the engine to be sucking in air or the starter cranking to cause the pump to run. During cranking there is a bypass that turns on the pump with the starter and while running there is a switch in the AFM that keeps it going as long as air is being sucked in. There is no electrical switch on the fuel rail or anything, so it's sort of a secondary way to click the fuel pump relay. But it works. Grim's link to 4Crawler is good, Roger has lots of FSM pictures for a pre-1989 EFI system.

Long story short, truck is running again, probably something to do with the relay. jumpered a battery straight to the pump, runs fine.

I'll post an update when I find out when get around to fixing it right.