Dash Light Lag Accompanied By Exhaust Sputter When Starting LC100

[2001LC]

Don't rule out throttle body just yet. It was the 2000, that had the most reports of issue with TB. You'll heard a sound as IG key turn to just ON, at throttle body. If you notice a delay in sound, that coincides with length of time IG keys needs to be ON before no symptom start. It'd be a clue.

Fuel Injector's to intake manifold grommet, would not be affected by KEY ON 3 sec:

The seal at bottom of FI's, are grommets in the intake manifold. Where they can leak air past them, it's not common with factory installed. But they are rubber, as such, shrink and harden with age. But if they are leaking air into intake ports of head, this would be a vacuumed leak. By spraying gasses like propane, gas from plumber touch etc.. RPM will increase as gas gets into area of vacuum leak. But a vacuum leak would not change, from just turning IG key to ON for a few sec. So this is not likely your issue.

If you do replace FI grommets. Make very sure, no dust/sand gets into port. Best time to replace FI grommets and seals, is when intake manifold off. Like during a starter job. Also in the 98-05 replace the O-ring & grommet at top of FI, in fuel rail. While FI's out, consider having cleaned, rebuilt & tested.

When to Clean or Replace fuel injectors

Please post your experiences and thoughts on the subject. I’ve been considering cleaning or even replacing all 8 fuel injectors, is this wasting time and money. I understand keeping fuel injector clean by adding a can of additive to the gas tank, now & then, is a good practice. This keeps them...

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A word on misfires read through Tech Stream (TS (Technical Stream of data, from vehicle systems)):

I had this glitch fool me on one 4.7L, at first. As misfire spotted in TS, would go away in a blink of the eye. Engine had at times, of rough start and driver felt something was off at idle. She had been driving it since mile one now over 350K miles, so knew her engine "feel". What I found, fix the issue. Was replacing (with Denso coil) the only coil ,that had been replace previously. Which replacement coil, was not Toyota Denso or Denso.

Glitch in TS when watching misfires:



Fuel line & rail pressure, with IG key on:

I do not think fuel pumps fire up, until engine turning. But, I'm still learning ever day about systems in the 100 series, almost as much as I've forgotten:

It's been suggest, as I noted above! Which currently, "I am in doubt of". "Fuel pump fires up for ~3 seconds to build pressure in fuel rail, by just turning IG key to ON". I'm in doubt, because: If this the case where fuel pump did fire up. We'd not get long crank to start, due to excessive Fuel Injector leak down. Which is a condition we see.

I can think of two easy test I could do (with a proper functioning starting & fuel circuit). To test if fuel pump fires up even for just a moment when IG SW just turned to key ON, without engine cranking:.

1st) Disconnecting fuel line down stream off fuel filter, Easy, since no tools needed. Attach a hose to fuel filter and run to catch can. Turn IG key to just ON. if fuel pump does fire up, fuel would pump into catch can. Best time to do this, to reduce fuel spillage or spraying. Is after vehicle has sat and engine cold. As fuel pressure in lines drops with passage of time.

2nd) I do with my pressure gauge setup. Which I tie in between fuel filter and fuel line to engine. Once hooked up, I'd only need to turn IG key ON. Than read the gauge!

Key on 3 seconds or more:
I do have one 100 series that comes to me for service. That needs IG key turn to ON 3 seconds or more, or it just cranks without starting. It had a very bad battery short, due to battery tie down missing. Apparently a shop fix damage caused. One thing, they installing aftermarket immobilizer system. Seems electronics need, time to activate throughout system.

 

[Les Summer]

PROBLEM SOLVED:
I spent the afternoon with the Land Cruiser. The first mission was acquiring MAF sensor cleaner. I retested my MAF reading from my scanner to confirm the reading as HIGH between approximately 9.15 and 11.15 g/s. I then cleaned the sensor with a little help from a member on here who posted a how to YouTube video; YouTube user "Cruisin With Greg". I retested with my scanner after cleaning the MAF sensor. The MAF reading decreased to between approximately 4.96 to 5.14 g/s. Additionally, I replaced the vacuum hoses you see in the attached photos. There were cracks on the ends of each one of those hoses, and they were all very hardened. I also found the hose clamp to my throttle body to be loose.

Thank you again member @2001LC. your pointers led me to check the MAF sensor and my hoses, and my starting hiccup is no longer. Truck running smooth again.

 

[Les Summer]

UPDATE: Well, could have sworn it was gone but the starter wine accompanied by sputter on fast key start is back.

Be cautious of those who only tell you about their successes and not failures.

I am going to just monitor it, and start saving for a good DENSO OEM fuel pump kit. I'm not mad at replacing a fuel pump with 275k miles on it, even if I don't need it yet. In the mean time I'm going to grab one of those banjo bolts and take to getting a fuel pressure gauge for testing. Truck always starts, just has that periodic sputter start if I don't leave the key on for a few seconds first. Oh well. I thought I had it.

 

[Les Summer]

Don't rule out throttle body just yet. It was the 2000, that had the most report issues issue with TB. You'll heard a sound as IG key turn to just ON, at throttle body. If you notice a delay in sound, that coincides with length of time IG keys needs to be ON before no symptom start. It'd be a clue.

10-4

 

[Les Summer]

This is valuable in teaching you how to check fuel pressure.

 

[2001LC]

I made a down stream fuel filter adapter, just for 100 series. For easy no tool hook-up to test: Dampener, static fuel pressure, engine idling pressure and leak down..
Using the most basic gauge kit, along with some old fuel rail parts.

FSM has connect on the fuel rail. But I use above adapter (cheat). .

ON-VEHICLE INSPECTION​

1. CHECK FUEL PUMP OPERATION AND FUEL LEAKS

(a) Operate the fuel pump. (1) Connect the intelligent tester to the Controller Area Network Vehicle Interface Module (CAN VIM). Then connect the CAN VIM to the DLC3. (2) Turn the ignition switch ON. NOTICE: Do not start the engine. (3) Push the intelligent tester main switch ON. (4) Select Active Test and enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / FUEL PUMP / SPD.

(b) Check the fuel pump operation and for fuel leaks. (1) Check that the pulsation damper screw rises up when the fuel pump operates. If the operation is not as specified, check the following parts: Fusible link Fuses EFI relay Fuel pump ECM Wiring connections If no malfunctions are found in the aforementioned components, replace the pulsation damper. (2) Check that there are no fuel leaks after performing maintenance anywhere on the system. If there are fuel leaks, repair or replace the fuel leakage part.

2. CHECK FUEL SYSTEM PRESSURE

(a) Check that the battery positive voltage is above 12 V.

(b) Discharge the fuel system pressure .

(c) Disconnect the negative (-) terminal cable from the battery.

(d) Remove the front fuel pipe from the delivery pipe LH.

(e) Install the front fuel pipe and SST (pressure gauge) to the delivery pipe with the 3 lower gaskets and SST (adapter). SST: 09268-45014 09268-41190 90405-06167 Torque: 39 N·m {400 kgf·cm, 29ft·lbf}

(f) Wipe off any splattered gasoline.

(g) Reconnect the cable to the negative (-) battery terminal.

(h) Operate the fuel pump. (1) Connect the intelligent tester to the Controller Area Network Vehicle Interface Module (CAN VIM). Then connect the CAN VIM to the DLC3. (2) Turn the ignition switch ON. NOTICE: Do not start the engine. (3) Push the intelligent tester main switch ON. (4) Select Active Test and enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / FUEL PUMP / SPD.

(i) Measure the fuel pressure.

Fuel pressure:

265 to 304 kPa (2.7 to 3.1 kgf/cm 2 , 38 to 44 psi)

If the pressure is high, replace the fuel pressure regulator.

If the pressure is low, check the fuel hoses and connections, fuel pump, fuel filter and fuel pressure regulator.

(j) Disconnect the intelligent tester from the DLC3.

(k) Start the engine.

(l) Measure the fuel pressure at idle.

Fuel pressure:

265 to 304 kPa (2.7 to 3.1 kgf/cm 2 , 38 to 44 psi)

(m) Stop the engine.

(n) Check that the fuel pressure remains as specified for 5 minutes after the engine has stopped.

Fuel pressure:

147 kPa (1.5 kgf/cm 2 , 21 psi) or more

If the pressure is not as specified, check the fuel pump, pressure regulator and/or injectors.

(o) After checking the fuel pressure, discharge fuel system pressure .

(p) Disconnect the cable from the negative (-) battery terminal and carefully remove the SST to prevent gasoline from splashing.

(q) Reinstall the front fuel pipe to the LH delivery pipe.

 

[Les Summer]

I made a down stream fuel filter adapter, just for 100 series. For easy no tool hook-up to test: Dampener, static fuel pressure, engine idling pressure and leak down..

This adapter should do that. Just by replacing the M12 x 1.25 banjo bolt holding the aluminum fuel pipe to the rail. See pics

 

[Les Summer]

I made a down stream fuel filter adapter, just for 100 series. For easy no tool hook-up to test: Dampener, static fuel pressure, engine idling pressure and leak down..
Using the most basic gauge kit, along with some old fuel rail parts.


View attachment 3480300
View attachment 3480301

FSM has connect on the fuel rail. But I use above adapter (cheat). .

ON-VEHICLE INSPECTION​

1. CHECK FUEL PUMP OPERATION AND FUEL LEAKS

(a) Operate the fuel pump. (1) Connect the intelligent tester to the Controller Area Network Vehicle Interface Module (CAN VIM). Then connect the CAN VIM to the DLC3. (2) Turn the ignition switch ON. NOTICE: Do not start the engine. (3) Push the intelligent tester main switch ON. (4) Select Active Test and enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / FUEL PUMP / SPD.

(b) Check the fuel pump operation and for fuel leaks. (1) Check that the pulsation damper screw rises up when the fuel pump operates. If the operation is not as specified, check the following parts: Fusible link Fuses EFI relay Fuel pump ECM Wiring connections If no malfunctions are found in the aforementioned components, replace the pulsation damper. (2) Check that there are no fuel leaks after performing maintenance anywhere on the system. If there are fuel leaks, repair or replace the fuel leakage part.

2. CHECK FUEL SYSTEM PRESSURE

(a) Check that the battery positive voltage is above 12 V.

(b) Discharge the fuel system pressure .

(c) Disconnect the negative (-) terminal cable from the battery.

(d) Remove the front fuel pipe from the delivery pipe LH.

(e) Install the front fuel pipe and SST (pressure gauge) to the delivery pipe with the 3 lower gaskets and SST (adapter). SST: 09268-45014 09268-41190 90405-06167 Torque: 39 N·m {400 kgf·cm, 29ft·lbf}

(f) Wipe off any splattered gasoline.

(g) Reconnect the cable to the negative (-) battery terminal.

(h) Operate the fuel pump. (1) Connect the intelligent tester to the Controller Area Network Vehicle Interface Module (CAN VIM). Then connect the CAN VIM to the DLC3. (2) Turn the ignition switch ON. NOTICE: Do not start the engine. (3) Push the intelligent tester main switch ON. (4) Select Active Test and enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / FUEL PUMP / SPD.

(i) Measure the fuel pressure.

Fuel pressure:

265 to 304 kPa (2.7 to 3.1 kgf/cm 2 , 38 to 44 psi)

If the pressure is high, replace the fuel pressure regulator.

If the pressure is low, check the fuel hoses and connections, fuel pump, fuel filter and fuel pressure regulator.

(j) Disconnect the intelligent tester from the DLC3.

(k) Start the engine.

(l) Measure the fuel pressure at idle.

Fuel pressure:

265 to 304 kPa (2.7 to 3.1 kgf/cm 2 , 38 to 44 psi)

(m) Stop the engine.

(n) Check that the fuel pressure remains as specified for 5 minutes after the engine has stopped.

Fuel pressure:

147 kPa (1.5 kgf/cm 2 , 21 psi) or more

If the pressure is not as specified, check the fuel pump, pressure regulator and/or injectors.

(o) After checking the fuel pressure, discharge fuel system pressure .

(p) Disconnect the cable from the negative (-) battery terminal and carefully remove the SST to prevent gasoline from splashing.

(q) Reinstall the front fuel pipe to the LH delivery pipe.

Thank you this is excellent for everyone.

 

[Les Summer]

I've gone ahead and replaced my fuel pump. It appears the previous owner had a Delphi in there. I have not had any symptom starts yet since installing the new pump, and if it's not placebo affect, I'd say I notice a stronger start. Regardless if this fixes my symptom, this was on my TO DO list anyway. This 2000 LC100 has 271k on it, so why the heck not. I've got a TOYOTA OEM in there now, and it's peace of mind. Aside from discovering the last technician got slap happy with the impact gun and ruined two of the rear seat anchor bolts, I'd say I'm pretty relieved and happy to have this job done, and satisfied. I've posted some pics of the old pump. I have no idea how long the Delphi has been in there. My suspicion is the pump didn't fail, but wasn't running optimally anymore. I will report back here if my start symptom returns, and then I think it will be time for the fuel pressure test up front, and maybe time to look at vacuum switch valve and fuel pressure regulator, which I would not mind replacing, if push comes to shove. Special thanks to YouTube member for demonstrating this procedure so I could be successful.
Here is his video:

 

[Les Summer]

UPDATE AND I BELIEVE IT IS FIXED:
I'm going to go ahead and say with confidence that replacing the fuel pump solved this. I've been on several stop and start trips this evening, which included a trip for refueling, and the sputter symptom is gone. I can no longer replicate it. I am pretty confident it's not coming back. I can usually get the faulty Start once out of 3 or 4 trips, but I've counted about 8 park and starts today, and it's gone. @2001LC thank you again. If anything new pops up I'll update here.

 

[2001LC]

Good job! Glade I could help.

There's that "rabbit hole", aftermarket fuel pump! Interesting, its size is smaller than 98-05 OEM fuel pump. Looks as if the isolator, was also missing. Or, perhaps you'd already removed it.

My parts guy at Toyota Dealership. Included the isolator in my last fuel pump order. Indicating, it's commonly replaced with.

FWIW. I do my fuel pump jobs, just a little different than above video. I:

1. Remove only DS rear seat, pushing it back into cargo area.
2. I tie carpet up to the PS frt seat, with bungee cord.
3. After removing cover to tank. I power-wash and then use HP air to clean top of pump & tank.
4. Disconnect the negative battery post.
5. R&R pump, much the same. Although the 06-07 is a bit different.
6. Inspect tank for sediment, and clean if needed.
7. I replace gasket, at top of tank to pump assemble seal.
8. Use a 1/4" torque wrench, to reseat pump assembly bolts.
9. Torque in seat bolts.
10. Replace fuel filter & green lock clip. Using torque wrench, on inlet hard line.
11. Run a fuel pressure test, making sure: dampener screw pops up, pressure in ranch and leak down test all in spec. and no leaks.
12. Add 2 cans of 44k or equivalent, to full tank of gas.
13. Test drive, watching fuel trims.

 

[Les Summer]

No, the isolator was there, just wasn't when I took the photo. Yes I also replaced the big gasket, and I used all OEM clamps and hose. The filter, clamps, ISOLATER, and hose I bought from Toyota parts deal dot com.
I didn't recognize a size difference, but I pitched the old pump. Even if it were "still good", I'd never do all that labor again to put an aftermarket used pump in there. I'd sooner buy another OEM and keep it on hand. I didn't have access to a power washer or compressed air, so I used a nice big soft new paint brush to get after any dust and debris before I removed the assy, and it worked out fine. I did see some big rust flakes at the bottom of the tank, they looked flat. I was afraid I'd make more of a mess breaking them trying to pick them out, so I left them be. Looks like they came off the inside of the tank somewhere.

I have yet to do the fuel pressure test, but I probably will eventually. I'm sure someone will come up with a proper tie in kit that can be left there permanent, if that's not already been invented. I was considering the valve option that plugs into the fuel rail, which I posted earlier in this thread, but I don't trust it. I don't like a valve there that can open where there would be a bolt holding down that cross over aluminum line that bolts onto the fuel rail.

Looking at my pics again, holy cow, that pump does look smaller!! I didn't even notice that.

 

[Les Summer]

I get Coils & Spark plugs, form Denso or Toyota Denso. I buy from only Denso distributors or Toyota. There is so much China bootleg junk out there.

Glade to hear zero rust.

Sure wouldn't hurt to do fuel pressure and fuel Injector leak down tests. Typically with excessive leak down. The complaint is long crank to start.

OMG. Never argue with a Land Cruiser wizard. @2001LC. Tonight I sit humbled. Had PO303 misfire. Switched cyl 1 and 3 coil, now have PO301 misfire. After only 8k miles. Looks I should have just bought the Denso. I’m waiting on tow truck (forgot to carry a spare coil with me) luckily I carry AAA (you should too). I saved the old denso coils I had, so I’ll throw one of those back in and see what I end up with.

UPDATE: put in the old DENSO in place of the bad one and problem solved! no more misfire

I’m gonna make Hitachi send me a new one, and I think I’m gonna slowly start collecting some brand new Denso coils.

It took 8k miles for the first Hitachi coil to go bad… and yes, I have heard this can happen with a denso coils too, but I don’t know how rare it is. I’m sure it's more rare with the denso..

I'm so glad this was an easy fix. I still can't believe it.

 

[2001LC]

OMG. Never argue with a Land Cruiser wizard. @2001LC. Tonight I sit humbled. Had PO303 misfire. Switched cyl 1 and 3 coil, now have PO301 misfire. After only 8k miles. Looks I should have just bought the Denso. I’m waiting on tow truck (forgot to carry a spare coil with me) luckily I carry AAA (you should too). I saved the old denso coils I had, so I’ll throw one of those back in and see what I end up with.

UPDATE: put in the old DENSO in place of the bad one and problem solved! no more misfire

I’m gonna make Hitachi send me a new one, and I think I’m gonna slowly start collecting some brand new Denso coils.

It took 8k miles for the first Hitachi coil to go bad… and yes, I have heard this can happen with a denso coils too, but I don’t know how rare it is. I’m sure it's more rare with the denso..

I'm so glad this was an easy fix. I still can't believe it.

Glade you found it. Be very careful, where you but your Denso coils or spark plugs. China has been flooding the market with bootleg Denso, NGK, etc.. So many bootlegs getting into the system. Even at top name retail part stores.

 

[Les Summer]

To add to my coil failure, I believe I need to replace my spark plug tube seals. I found a little bit of oil on the bad coil. I believe I have a small leak or I possible spilled by the filler neck during last oil change. either way, it's probably time for a gasket job.

 

[2001LC]

Personally, I would have removed any foreign matter from tank. Most times, what we're seeing is rust from old metal underground fuel storage tanks. Large chucks just haven't broken down yet. Large pieces are sign, they recently pumped in. In time they break-up as they slosh around. As they break up, they get into sock, motor and smallest all they way to engine compartment fuel filter. This can reduce life of pump. It can also reduce fuel flow, resulting in lean running engine.

I re-torque head cover bolts, to 53 INCH.lbf. To date, this has stopped all head cover leaks/weeps. Exception: The only head cover and tube seals, I've had to replaced. Are when someone, previously replaced (Mostly aftermarket).

If spark plug tube seal leaks, you'll see oil on that seal at top of tube.

When I replace spark plugs. I typically use the Denso TT (IK20TT). I first started using these TT, since (at the time) no one could duplicate the .4mm tips. This made spotting the bootlegs easy, For me. As their (bootleg) tips were larger (standard size diameter). I also use a 18ft-lbf torque (using Denso scale), rather than Toyota spec of 13ft-lbf. This is to see, if it buys more time until spark plug loosens "walking out" . While I replace plugs, I install Denso coil boots & top seals. The top seal keeps, contaminants out of spark plug tube. This is also when I retorque head cover bolts.

BTW: Never use anti-seize on out spark plugs.

Sure, you can set-up a permanent fuel pressure gauge. They can be; "read only when hood open, looking at gauge". "Wired into cabin for continuous monitoring" or "wireless read on smart phone ect". Let your wallet dictate, which. But typically they not needed.

Note: Very often, when we find oil on base of spark plug. It's due to combustion gasses, blowing by threads of loose spark plug.

Ticking time bomb TICK TICK TICK: Spark plugs Alert Alert Alert!

TICK TICK TICK POP POP POP is a ticking time bomb, often mistaken as exhaust manifold crack or gasket leak leak. ALERT, ALERT, ALERT: Spark plugs are working themselves loose. "Walking Out" Then blowing out of head, taking their female threads of head with them! Very damaging! You think TICK...

forum.ih8mud.com

 

[Les Summer]

I re-torque head cover bolts, to 53 INCH.lbf. To date, this has stopped all head cover leaks/weeps. Exception: The only head cover and tube seals, I've had to replaced. Are when someone, previously replaced (Mostly aftermarket).

Ahh, yes. So today I was very busy. I redid the valve cover gaskets and tube seals. on both sides. I was very involved. Sure enough, the aftermarket tube seals were the culprit. It's no wonder I burned up my coil. the tube seals, clearly not OEM, were all lop sided, and I was able to remove them by hand. It was like they were either really poorly manufactured, or not the right size. The valve cover gaskets were perfectly fine, but just like the tube seals, I replaced them with OEM gaskets. I am now dry and doing fine again.

I didn't bother with a torque for the cover bolts. My wrench batteries went dead in the cold garage, so I had to rely on feel. I just crisscrossed and made sure I wasn't going ape.

I pardon the Hitachi coil failure do to the aftermarket junk tube seal that was in there. The Hitachi coils are still going to get their fair shot at 100k miles. The new OEM tube seals had to be hammered in with a socket, which was satisfying. I'm sure they will seal up and stay put for a long time. I was very careful putting them in. I used Toyota FIPG, or whatever yacallit, black sealant for the corners and half moons. Just drove 200 miles and not leaking one drop. Rockauto sent me a brand new Hitachi coil still under warranty to replace the one that got drenched in oil.

Personally, I would have removed any foreign matter from tank.

Not sure when I'll be revisiting the fuel tank, but I might get after the flakes with a long turkey baster some day.

 

[2001LC]

Good for you!

Just a few things I'll mention.
Always clean top of engine, first.
Always blow out spark plugs tubes, before remove head cover.
Always check, to see that spark plug are tight
Always install bolts & nut with by hand to start, then hand tools to finish.
Always use a torque wrench. It's about a specific pressure, that takes in to consideration heating, cooling, stresses, material, etc. It's not about breaking a bolt.

The oil in spark plug tube would not damage coil,. Here's why I sat that:
There is an issue in the 5.7L, where some spark plugs tube fill with oil. It's a non event according to Toyota and they will not fix under warranty. It where tube leak at pressing in point on head. Toyota fix, replace the heads. A guy has a fix, where heads remain in place. He'll not talk about much in mud, but we've talk. Questions I've asked: In the more than 20 5.7L engine he's re-sealed tubes t head. Has he seen damage to coils and any improvement in MPG after service. He said NO. Also worth noting, some engine are designed with coils submerged in oil.

When I see burnt coils in our 4.7L, it's from one cause. Hot gasses! Spark plug walking out, and the hot gasses pass the threads cooking the coils. VERY BAD!

Ticking time bomb TICK TICK TICK: Spark plugs Alert Alert Alert!

TICK TICK TICK POP POP POP is a ticking time bomb, often mistaken as exhaust manifold crack or gasket leak leak. ALERT, ALERT, ALERT: Spark plugs are working themselves loose. "Walking Out" Then blowing out of head, taking their female threads of head with them! Very damaging! You think TICK...

forum.ih8mud.com

 

[Les Summer]

When I see burnt coils in our 4.7L, it's from one cause. Hot gasses! Spark plug walking out, and the hot gasses pass the threads cooking the coils. VERY BAD!

It wasn't loose. I say my coil was "burnt", but it was just a coil that malfunctioned. It wasn't actually burnt. Plug was not loose. I'm glad to hear that oil doesn't totally ruin them, that makes me feel a bit better. I was wondering if all the other coils were gonna poo poo too.

 

[2001LC]

OH!

BTW: It's easier to replace PCV grommet, while head cover off. If it's old and hard.