Hard to start 3B, lots of cranking, white smoke (1 Viewer)

[deaddrift]

Today my engine decided it doesn't like to start now.

It sat overnight; first start today went fine. Thenm out of the blue, the second time I went to use it, it required two glows and LOTS of cranking... then eventually started with a huge puff of white smoke (unburnt fuel?). Temps are 70-80 F here right now.

Same thing again later in the day after sitting for a few hours. When I parked the truck and then came back to it just a few minutes earlier it started right up.

I have been burning biodiesel almost exclusively since I got this truck over five years ago. However I never replaced the fuel lines. Would air in the lines from a leak cause these symptoms? I should also note that it was much harder to start last winter too. The glow plugs were replaced three years ago with new at FSM specs for voltage.

Any ideas?

 

[Bandit_guy]

White smoke on start is unburnt fuel. It's sound like lack of heat on start. Your glow plugs might be only three years old but rest of the glow system is pretty old and could be at fault. That is the area I would look into.

 

[lostmarbles]

I second the idea of properly checking out the preheat operation.

(I don't think it is ever wise to assume something still works simply because it hasn't seen much use.)

If it's got a rotary-type injector pump (rather than an inline pump) then checking for any leak that may be causing air to enter the fuel line would be my next step.

 

[deaddrift]

My FSM is showing me how to check continuity on the different elements of the preheat system, but it also says in the troubleshooting section that the starter pinion gear teeth or flywheel teeth might be broken. However I think if this were the case I wouldn't be able to start it at all, right?

The starter is cranking fine and sounds same as always, however the engine will not catch.

Please advise, I am a real novice, and everything I do to my truck is brand new to me. Thanks for the help.

[EDIT] I seem to hve three, not two, glow relays on my fender. What my FSM calls #1 tests OK. It is roughly cylindrical in shape. There are two rectangular/box-shaped relays also, and each has two connecters coming from it. One says it is a glow relay and the other has no text on it.

 

[Bandit_guy]

From what I see from the EPC and you signature it look's like you have 12 volt super glow system. Here's a few things to help diagnose if you do in fact have a preheat problem. If you have a block heater installed or some way to heat the engine, plug it in and get it hot. Turn the key to start without glowing it and if it starts fine then pre heat is your issue.

If it is a pre heat problem attach a multi meter to the buss bar connecting each glow plug together, then turn on the key and look at the voltage. If every thing is normal you should see 12 volts for a few seconds, then a drop to 6 volts for up to 45 seconds then no voltage. If you get this your relays are functioning properly and the glow controller is as well.

From what you see from this test there are lot's of possibilities and quick fixes. There are lot's of long fixes as well.

If you get continuous 12 volts never 6 volts. You have a bad controller and your Glow plugs are fried or you don't have super glow installed.

If you get 6 volts only and never 12 volts, the barrel relay is not working properly (stuck relay or broken wire and you aren't getting 12volts to the plugs), the glow controller is not working properly, some the connections to the glow controller are broken or your plugs are warn out.

A quick fix for a bad controller is to install a wilson switch. There are lot's of threads on how to do this.

For bad plugs, replace the plugs. I went after market a few times and they didn't last so I spent the $$$$ on Toyota plugs and I'm happy now. Lot's of discussions on this as well form your opinion with hours of reading. When the glow plugs heat up the resistance increases and the excess current is what triggers the glow controller to cut one of the relays. Worn plugs will achieve the magic resistance limit at lower temperatures so and the controller will drop the current to soon resulting in a lousy start.

If Preheat is not you issue then compression and fuel delivery are the other areas to check.

Good luck

 

[cruiser_guy]

Get a buddy to assist you and do this test cold (without having tried glowing it for a while).

Multimeter set to DC volts from battery negative to one of the glow plug tips.

Have buddy turn to the "Glow" position and see if you have voltage at the glow plug. The voltage will drop quickly so you need a buddy and you need to be ready as soon as your buddy turns the key. If you do get voltage the relays and all else are OK. You may still have burned plugs.

 

[deaddrift]

Thanks cruiser guy and Bandit guy.

I tested all the relays per the FSM procedure and they all test good. I tested the one box-shaped relay that says "glow system" on it and left the other alone. If I can find my camera I will take a pic to show what I mean.

When I tested continuity on the plugs themselves I got a reading of ~.572 on all four plugs to ground. I scraped the ground clean to bare metal. I don't know why I would have what appears to be partial continuity? What the heck?

Also, summer temps being what they are, how likely am I to really need the pre-heat function? I'm pretty sure I haven't even needed to glow it in this kind of weather in the past, though I usually do because why not.

My mechanic also suspects air in the fuel lines. When my brother-in-law comes by I will test the mechanical function of the EDIC and crack the injectors to test fuel delivery to the block. I'll also retest the glow plugs as you describe.

 

[Bandit_guy]

You need to preheat on every start your engine is not at or close to operating temperature to get a start when it's hot you just need less time to get there. If the start system could handle it you could crank a cold engine until the combustion chamber got hot enough to auto ignite then introduce the fuel and get a start that way with the same result.

To check the for air in the lines use the hand pump if it's not rock hard when you pump you have air entering before the filter. When I prime mine if I don't bleed fuel when it's done I'm not strong enough to get it back down and locked

To check your EDIC if you have long arms or an assistant look at the motor while the engine is getting cranked and if it starts where it sits when it runs.
The arm should be all the way forward when you begin, then move all the way back while you crank and then sit about near the middle when it's running. If it doesn't start it will move back to full forward a few seconds after you stop cranking.

 

[deaddrift]

When in preheat mode the bus bar shows 12.36V until the relay clicks, then 4.64 V.

I get fuel coming out in spurts at the top of the injectors on the block when I crack them and have my brother in law crank the starter. I don't actually know exactly what to look for because I have never bled my fuel system, but I am not seeing any bubbles, just pulses of liquid fuel.

The pump is a Bosch replacement and I can not push it down more than a few mm, but again, don't know if my procedure is right. Does this pump need to be open and closed or should it just depress when the system is open for bleeding and resist when the system is closed? Please advise.

Thanks for the help.

 

[lostmarbles]

My FSM is showing me how to check continuity on the different elements of the preheat system, but it also says in the troubleshooting section that the starter pinion gear teeth or flywheel teeth might be broken. However I think if this were the case I wouldn't be able to start it at all, right?
The starter is cranking fine and sounds same as always, however the engine will not catch....

You certainly can't have any starter problem if your engine is cranking fine but simply doesn't fire up.

Thanks cruiser guy and Bandit guy.

When I tested continuity on the plugs themselves I got a reading of ~.572 on all four plugs to ground. I scraped the ground clean to bare metal. I don't know why I would have what appears to be partial continuity? What the heck?..

Yeah. You're certainly getting excellent advice there from Bandit and Cruiser Guys.

You may see some conflict in our advice... but there can be other factors to take into account..

For instance a 3B engine that has excellent compression may start well without preheat at 70 oF (22 oC) but when an engine is a bit worn it may need preheat every time.

(My B-engine needs preheat all the time, unless its stopped running only 30 minutes or less ago.)

(And thanks for adding your vehicle details in your signature line.)

Did you remove your busbar when checking the continuity of each glow plug? (If you didn't you wasted your time because the current from your meter would have been travelling multiple other routes rather than just through the one plug your trying to test.)

..Also, summer temps being what they are, how likely am I to really need the pre-heat function?[/b] I'm pretty sure I haven't even needed to glow it in this kind of weather in the past.
My mechanic also suspects air in the fuel lines. When my brother-in-law comes by I will test the mechanical function of the EDIC and crack the injectors to test fuel delivery to the block. I'll also retest the glow plugs as you describe.

Poor compression and poor spray pattern from the injectors could be causes for the deterioration in starting performance.

From the details now in your signature line, I think you have an inline injector pump with no fuel-return line back to your fuel tank. In that case I think air contamination is unlkikely.. Because if air was trapped in that type of fuel system I doubt your engine would EVER fire up without first having manually bled the trapped air out using the primer and bleed nipples. (And you say it does sometimes fire up if you keep cranking.)

And I see you've just added another reply while I've been typing up this ........

When in preheat mode the bus bar shows 12.36V until the relay clicks, then 4.64 V.

I get fuel coming out in spurts at the top of the injectors on the block when I crack them and have my brother in law crank the starter. I don't actually know exactly what to look for because I have never bled my fuel system, but I am not seeing any bubbles, just pulses of liquid fuel.

The pump is a Bosch replacement and I can not push it down more than a few mm, but again, don't know if my procedure is right. Does this pump need to be open and closed or should it just depress when the system is open for bleeding and resist when the system is closed? Please advise.

Thanks for the help.

Sound like your fuel system is OK.

So I come back to asking you whether you checked the continuity of all your glow plugs correctly. ie Did you first have your busbar completely removed?

 

[deaddrift]

Thanks lostmarbles.

The current reading I posted just above is from the connected busbar to ground while engaging the superglow system.

When I took the busbar off and checked continuity on the advice of my mechanic I ran into a problem. The glowplug has a pin on top that connects to the busbar and then a rubber o ring and then the plug contacts the block. I have 1 ohm resistance at the top of the plug and .001 at the bottom. Same reading on all four plugs. If I understood my mechanic right I should be seeing ~0.2 from the top to the ground on the engine block. But how can this be? What am I getting wrong on this test?

What about compression issues? Would I see a dramatic change during the course of just one day if this were a compression problem?

The EDIC functions correctly as described. There is also no water in the sedimenter. (I have never seen water come out of that thing in five years.)

Also the engine will not fire up, even with extensive cranking, today. It worked yesterday, twice, but now now.

 

[deaddrift]

AND: why am I seeing smoke coming up from under the heat shield over the exhaust manifold when the starter is cranking? It is not coming from the blowby tube.

 

[lostmarbles]

Thanks lostmarbles.

The current reading I posted just above is from the connected busbar to ground.

When I took the busbar off and checked continuity on the advice of my mechanic I ran into a problem. The glowplug has a pin on top that connects to the busbar and then a rubber o ring and then the plug contacts the block. I have 1 ohm resistance at the top of the plug and .001 at the bottom. Same reading on all four plugs. If I understood my mechanic right I should be seeing ~0.2 from the top to the ground on the engine block. But how can this be? What am I getting wrong on this test?

What about compression issues? WOuld I see a dramatic change during the course of just one day if this were a compression problem?

I don't worry about the actual ohm reading of a glow plug because I find the reading I measure never matches what Toyota says they should be.

Instead I'm only interested in "continuity" (ie. whether there is a circuit through the plug or not)..

The correct test is from the threaded connector at the top to some shiny metal somewhere on the engine (and the aluminium intake manifold is what I normally take as the earth reference point).

So from your test results of 1ohm for each plug it appears you indeed have continuity on all four plugs. And if your glow system is feeding 12.36V in stage 1 of Preheat and 4.64V in stage 2 of Preheat/Afterglow then that seems to be in order from what I know...

No.. I would not expect to see any change in compression during just one day of driving.

So this is a bit of a puzzle.

Maybe try starting it from a separate container of proper diesel in case it is a fuel quality issue here?

Or maybe CruiserGuy or BanditGuy have other suggestions...

 

[lostmarbles]

AND: why am I seeing smoke coming up from under the heat shield over the exhaust manifold when the starter is cranking? It is not coming from the blowby tube.

I'd get someone else to watch closely while you crank (or vice versa) so you can determine this.

It sounds unusual...

 

[deaddrift]

Wait, isn't 1 ohm NO continuity? I got that result from the top of the plugs to the block, same result top of the plugs to the negative battery terminal.

 

[lostmarbles]

Wait, isn't 1 ohm NO continuity? I got that result from the top of the plugs to the block, same result top of the plugs to the negative battery terminal.

Infinite ohms (an unimaginably-high number of ohms) represents no continuity (aka open-circuit).

So if your plugs are burnt out (open-circuited), placing one meter probe on a plugs threaded connector (while holding the other probe on intake manifold shiny metal) will cause no change of reading on your meter (compared to when your probes were touching nothing at all).

And conversely, if your plugs are good, the meter reading will change when you touch the threaded connector (and give you a reading).

Here's some pics of how it's done with a cheap-and-nasty analogue meter:




(One day I should take the same pics with a more common digital meter.)



PS. Infinity is on the left of the scale on that meter and zero is on the right.

These old analogue meters make more sense than digital meters because a digit meter can't say "infinity".

EDIT

Hey... I think I've just stumbled across a mistake you may have made!

I just checked the digital meter I keep in my cruiser...

Because it can't say "infinity", it displays "1" instead.

So if your meter is the same and this "1" is what you saw... then all your plugs are open-circuited/blown.

What does touching the two probes together show? (It should show 00.0)

 

[deaddrift]

My multimeter reads "1" when the leads are separated and ".000" when the two leads are touching each other. It is digital. I sometimes see slightly higher readings when examining real-world circuits that are continuous, like ".001" or ".002". I take this to be the minimal resistance of the wires.

When I touch the the very top of the glow plugs, with the busbar removed, and touch the other lead to a ground (specifically shiny intake manifold metal, which I sanded up for just this test) I see no change. I take this to mean that all four plugs are shot? Why would this happen all-of-a-sudden?

Right now the air cleaner lid and intake hose are off so I could get the heat shield off. I found out I have no top bolt on the rear of the exhaust manifold; that is, there are three along the top and then an open hole where a bolt should be on the last cylinder closest to the engine wall. Now I know why smoke is coming out from there, and I might know why my engine seems louder recently. It also looks like getting at that area to replace bolts is going to mean a lot of other-assembly removal.

Just saw your edit, looks like new plugs for me.

 

[lostmarbles]

My multimeter reads "1" when the leads are separated and ".001" when the two leads are touching each other. I get sometimes see slightly higher readings when examining real-world circuits that are continuous, like ".002" or ".004". I take this to be the minimal resistance of the wires...

Your meter is probably more accurate than mine (or else you have more surface-muck on your probes) but otherwise both our digital meters agree with one another.

..When I touch the the very top of the glow plugs, with the busbar removed, and touch the other lead to a ground (specifically shiny intake manifold metal, which I sanded up for just this test) I see no change. I take this to mean that all four plugs are shot?

Yes. We've just confirmed all your plugs are blown.

(And we've also shown why old-fashioned analogue meters are less confusing than digital meters when performing continuity/resistance tests.)

Why would this happen all-of-a-sudden?

Superglow systems do have a design fault.

Toyota's aim was to provide fast preheat so that owners don't get the "what the F.... are you doing" stare that passengers and bystanders often give me after I leap in my cruiser and then just sit there counting up 25 seconds in my head.

But ... if your engine doesn't start right away.... or if for any other reason you turn your key off and then back on again ... I believe you reactivate the first stage of preheat once again. Unfortunately your 6V plugs aren't capable of withstanding 12V being applied to them for more than just a few seconds. So turning the key off and back on again can cause their tips to melt internally from overheating.

..
Right now the air cleaner lid and intake hose are off so I could get the heat shield off. I found out I have no top bolt on the rear of the exhaust manifold; that is, there are three along the top and then an open hole where a bolt should be on the last cylinder closest to the engine wall. Now I know why smoke is coming out from there, and I might know why my engine seems louder recently. It also looks like getting at that area to replace bolts is going to mean a lot of other-assembly removal.....

Best to fix that ASAP.

Exhaust fumes inside the cab are bad for your health.

Not only that, but the hot gases squeezing through that gap between the manifold and head will gouge out a bigger path eventually making it hard for the manifold to seal again, even with a new gasket (without surface-grinding the exhaust manifold).

And a good tip here is to buy a genuine Toyota manifold gasket because others are often significantly thinner (and consequently are more leak-prone).

PS. The rear studs always seem to be the ones that break and they are indeed a pain to extract. (I've had to do it myself.)

 

[Bandit_guy]

Thanks lostmarbles.


When I took the busbar off and checked continuity on the advice of my mechanic I ran into a problem. The glowplug has a pin on top that connects to the busbar and then a rubber o ring and then the plug contacts the block. I have 1 ohm resistance at the top of the plug and .001 at the bottom. Same reading on all four plugs. If I understood my mechanic right I should be seeing ~0.2 from the top to the ground on the engine block. But how can this be? What am I getting wrong on this test?

I think you might have dead plugs. When you get a 1 reading on a multi meter it usually means your in a too low ohm setting. Try it at the 100 ohms or thousand ohm setting and see if you still get 1. If one ohm is the real result it should show 1.0 at the 100 ohm setting and 0.0001 at the thousand ohm setting. Cold plugs are in the low ohm range 0.9 and lower so high resistance is a indicator worn plugs. Like marbles said the bus bar must be removed or else your checking the path of least resistance from something else. Top of the skinny pin to the block or negative terminal should give continuity at least if not it can't produce heat.

When it did start was it running normal, bad injectors and compression would give you lousy performance before no start, so from my arm chair I still put money on glow plugs being pooched

Keep on trucking you'll get it

 

[deaddrift]

So the parts I need:

4 6V glow plugs for 3B engine
1 3B exhaust manifold gasket
1 replacement bolt for the manifold
Also 1 intake hose from air cleaner to intake manifold (not metal tube or rubber elbows, the rubber accordion hose) because it has age cracking.

And: Lesson learned, don't glow multiple times or you will burn out your glow plugs prematurely.

Many, many thanks Bandit guy, cruiser guy, and lostmarbles. Definitely couldn't do this stuff without the help of the excellent members here.