Just bought the truck
1994 3.0, automatic trans. 214k
Truck sat in garage for 5 years
Full story.
I jumped the truck she started right up. ( Valve cover leak and fuel leak from the fuel pulsating damper.
Full tune up: oil/filter, plugs/wires, air filter, trans filter/fluids. EGR delete LC engineer, vacuum hoses, pcv valve
I replaced both the valve cover gaskets and the Fuel pulsating damper/washers (oem part). Plenum removed
Prognosis... After buttoning her up. She cranked right up...idled just fine...no issues, brought her up to operating temp. 15 min at idle. Took her out on a victory lap...5 min down the road...completely shuts off, entire dash lit up...felt like no fuel.. got it towed home.
Replaced the fuel pump and cleaned out the throttle body. (Getting a 41 code)
I've checked the fuel pump, runs
Truck won't start. (Starting fluid gets it started but dies

Questions:
1. Can fuel banjos be tightened too tight where they prevent fuel from passing? Cross over fuel line, removing the FPR.
2. Can the tps sensor be replaced simply or does it need to be adjusted? (Code 41, would this not let her crank or just poor idle)
3. Can replacing the fuel damper/ fuel leak, change in pressure affect ecu and fuel regulation?
4. Should I replace the fuel regulator, would it fail from age and a sudden increase in fuel pressure...sat for 5 years
I'm stumped...checked the MAFS (bypassed) fuel pump is running; and the TPS (multimeter). Checked all the fuses !no blown fuses), relays click.
Getting fuel, spark and air... Just not cranking
Fixed all the leaks (ran fine leaking all over the place). Buttoned her up and now she won't start....
FYI sorry for the long post but tried to put in all the info.

 

Eye strain to the max. If you edit the post, I might be able to read it.

 

If you put the thick and thin crush washers on in the wrong position it will impead fuel flow.

 

All these new users with a proper "First" and "Last" name.
Not sure these are in fact real people but maybe it's a generating "millennials" thing?

Whatever happened to actual user names? Outdated in times of "Facebook logs you into anything with your real name"?


Only thing I got is it's running off the cold start injector and all the others don't actually fire. So it will idle and sort of run, until it warms up?

 

Is the EFI fuse under the hood still good or did it pop?

 

First: Yancy is new to YotaTech (Welcome!). So he posted his question in the newbie Tech Section, and here. To save typing, he cut-and-pasted his post to here. This (often) screws up the font color. So Yancy can just edit the post, highlight all the text,

click on the "font color" icon, and select Automatic. (Don't pick any other color, not white or black, unless you really want to experiment.)
Vocabulary: Usually, when one says "it's not cranking," they mean the crankshaft is not turning. Like a bad starter. It sounds like yours will crank fine, it just doesn't fire. (at all) Correct?

This is where I would start. Code 41 is "Open or short detected in throttle position sensor signal (VTA) for 0.5 sec. or more" (you knew that -- why didn't you say it? Don't expect that every member of this forum has memorized the text for all 20 codes.) So with your multimeter you need to test that the VTA terminal sweeps smoothly through the voltage range as you move the throttle. More importantly, the code says that the ECU has detected a short or open. So it might not be in the TPS itself, but in the wiring to the computer. If the TPS seems to work, you may need to run the check again at the connector to the ECU.

No you didn't. You don't have a "Mass Air Flow Sensor." You have a "Volume Air Flow" sensor (VAF). Different technology.

The answer to these questions is (probably) "no." But it sure sounds like a fuel delivery problem. Start with the easiest test. Replace the fuel return line from the FPR with a clear vinyl 6mm (1/4") tube to a suitable container. Start the fuel pump with FP=>B+ in the diagnostic connector. (This forces the fuel pump to run with key-on.) I get about 1/2 liter/min out the return line. If you don't get any fuel, I would suspect a problem in the VAF-COR circuit. If you do get fuel flow, you can go on to test fuel pressure. You'll (probably) need a 12mm banjo-schraeder adaptor (I installed mine at the FPR) to connect a common fuel pressure gauge.

Last, concern about "banjos tightened too tight" sounds like you reused the crush washers. Don't. They are one-time-use, and if they leak, it's gasoline we're talking about. Easiest place to get them is from the dealer, but they're cheaper than dirt. FWIW, the spec is 25 ft-lbs.

 

Truck won't start. I've replaced everything except the COR, EFI relay, and fuel pressure reg. Will start with starting fluid but won't stay on...

I had no problems with it before I pulled the plenum and fixed the fuel damper and valve cover gaskets

 

EFI fuse is still good. Replaced it for good measure 15a

 

I attempted to fix the Font...apologies

You are correct, the engine is cranking, just not firing.

I did (FP=>B+) to check the fuel pump and it's is running, i Remo Ed the fuel pressure regulator line and it's definitely moving fuel...alot..

I did try to test the TPS but I didn't have the gauges and the detailed instructions are overwhelming.

I used a multimeter in the VAT and all read within the FSM specs.

Is there a way to test the COR? I'll probably order one and replace it anyways...

I did reuse the washers (shame). I wasn't expecting to have to remove the cross over fuel line. There are no leaks though.

What I don't understand is the car had fuel and was running fine for a while and it just let go... I've triple checked all the vacuum lines and fuel lines and removed the throttle body and cleaned that. I ordered a new tps as well.

 

Did sign in with Facebook... Got me! It cranks but won't start. Starting fluid gets her to run for a couple of seconds the she dies

 

Sigh ... Sure. Order a $95 relay https://parts.lakelandtoyota.com/p/_...591035010.html even though the one you have is probably good. What chance is there that you will accidentally fix your problem before you go bankrupt replacing parts willy-nilly?

You can test the COR by using your finger to open the vane in the VAF with key-on. The COR should close, and start the pump. The COR initially closes with key to STArt, but that's tricky to test unless you disconnect the solenoid wire from the starter (because you can't hear the pump over the starter.)

Then why are you getting code 41? The FSM only has VTA specs for throttle open, and throttle closed. But if you have a drop-out in the middle of the internal rheostat, and hold the throttle there for 1/2 second, the ECU has nothing to read. That's why you would benefit from a sweep test. Also, you don't know if that signal is getting back to the ECU. BUT ... you could have an intermittent problem. Here, I'd start with resetting the codes (remove the EFI fuse for about 30 seconds). You probably won't get it back until you can drive it, but you'll need to reset the code at some point anyway.


The pressure side or the fuel return side? If you removed the pressure line you'll need to replace the crush washers. Just because it isn't leaking now doesn't mean you won't die a horrible, flaming, death in a few weeks. The reason you remove the fuel return (other than it doesn't need crush washers) is it confirms fuel is reaching the FPR with enough pressure to get through the FPR. Even low pressure from a failing fuel pump looks like "a lot" when you just spray it all over the place.

Oh, c'mon! That setting is just to assure the idle switch is closed when in idle, open when off idle. (It's a little complicated because with real world parts, "throttle closed" has be defined, and "contacts closed" does too.) But this has nothing to do with code 41, and very little to do with no-start.

How did you check for spark? The easy way is with a timing light, a $30 tool which you need to have anyway. If the distributor is not giving the IGT signal, the ECU doesn't know when to open the injectors.

 

Scope103, I appreciate the help.

I checked the COR and I'm sure it works. It's definitely opening and closing and I can hear the flap in the VAT open and close with the turn of the key. I've reset the codes several time. (That EFI fuse has been removed and replaced on several occasions, not blown) replaced both EFI fuse and relay.

I removed the pressure line and did as you said "attached a tube into a bottle. I will order the long banjo and do a proper fuel pressure test.

I didn't necessarily check for spark because she starts with starting fluid but just doesn't stay on. I did remove the timing belt cover and the belt is intact but I will check the timing in case it's skipped a tooth or shifted (don't see how).

Im not necessarily throwing parts at it Willy Nilly... I knew this truck would have issues getting into it. It sat for 5 years, so I budgeted for parts and I am replacing the common failures as I'm going through the diagnostics of it.

After testing the pressure. Hypothetically it's low, below 33psi; would the culprit be the fuel filter? I try to install Toyota Denso parts whenever I replace. Fuel pump is Denso and hums strong.
Would low fuel pressure completely stop it from running or run weak and erratic...especially not under load I feel like it would still start.

Checking the spark with a timing light would show me the distributor and wire are solid... Im fearing that the wires to the injectors may have gotten damaged during the reinstallation of the plenum... But it ran strong for 20 min before shutting down unless driving finally severed something. (I feel like that would throw a code).

I fixed and replaced so many things that it's honestly difficult to know if it's something replaced that's causing the issues or the truck is just overwhelmed, she hasn't felt this much love in years. Lol

 

I can read the post now!

Get a noid light, and check the injectors. Here is a post on this forum from a member that made a home made noild light tester.

https://www.yotatech.com/forums/f116...t-22re-270857/

I know when some engines jump a tooth or two they sound like they want to crank, but they won't. Not sure on the 3.0, but it sure is sounding like it could have possibly jumped timing. Just find top dead center on #1 compression stroke, and then go from there.

 

Well, for what it's worth breaking a wire to an injector will NOT throw a code. But losing one injector will just make it run like puke, not stop it from firing altogether. All the injectors fire together (though they may be wired in two strings of three). Shorting a wire to ground (or breaking one) COULD happen with vibration, and that could stop the injectors from opening.

You could borrow a set of "noid" lights from a place like O'Reilly's. Or you could make your own with a 12v LED. LEDs are polarized so you have to hook them up in the correct direction. One terminal of each injector is always at battery voltage (with key-on), and the other is grounded by the ECU to open the injector.

I would expect that if you have enough pressure to pump 1/2 liter/min through the return line, you should have enough pressure to at least get it to fire. So then I would look to the injector wiring. Hence, the "noid" test.

 

Update....

Replaced the fuel pressure regulator. Borrowed a fuel pressure test or from AutoZone, read 44psi and wouldn't hold pressure once turned off. New pressure regulator read 38psi and holds the pressure for several minutes after shut down (replaced banjo with new crush washers!)

Replaced COR.

Tested the spark with a intermitten spark tester attached to the distributor and the spark plug. Lite up like a Christmas tree.

Replaced TPS sensor and adjusted it to spec with FSM guidelines. Also tested before installing with throttle body out and appropriate shims.

Still no start. Next will be a igniter and new coil.

Any other suggestions out there....

At this point it's either the VAT, ECU, timing or.....I have no clue....

 

If it runs with starting fluid, it's probably not ignition (timing, plug wires, etc. are probably all good). If you have fuel pressure on cranking it's probably not the COR or VAF (or fuel pump or fuel filter). Problems with the TPS are unlikely to lead to no-start.

While I'm not standing where you are, my next guess is the injectors are not opening. They're no fun to get to on the 3VZE, but my next step would be to check for injector pulse on 2-4-6 at least. Since the plugs are firing, IGT is getting TO the igniter (so the ECU has the signal to open the injectors). If the injectors aren't opening, I'd look for damage to the wiring from the ECU to the injectors. Probably not a single bad connection (that would take out only one injector), but a wire broken closer to the ECU, or a short to ground.

 

FYI. I'm chasing somewhat similar behavior on mine. Once it reached operating temp, I have trouble restarting.
AFAIK, its an issue with the CSI and the Time sensor. My time sensor reads 60ohms where it should be 20~40. Need to do some debugging but I was able to successfully restart the engine if I unplugged the CSI. Need to debug to see if its the sensor or the CSI.

 

Dies while running and doesn't restart when warm are not even vaguely the same issue/symptoms. The CSI system is not active for but a brief time, miles.down the road it has certainly shut of or its a leaking POS that's gonna flood your oil with fuel and maybe even hydro lock..

(Start your own thread if you need help.)

 

You're right. Started posting before my morning coffee

 

Pulled the plenum again and inspected wires...

One set of wires was stripped and touching possibly grounding out.
Ripped apart the wiring harness and checked the power (12v and all the splices for the injectors and all were good. Also checked each injector at the base for 12 and all were good. I hope the stripped wires was the issue.

Each injector was pushing out 14.6 ohms

Also checked the ecu for power on the #10 and #20. And E01/E02 all showed 12v..

Really hope it was the stripped wiring... Pics

Those stripped lines were touching

More stripped injector lines

Would one grounded injector shut them all down or just the single one?