2H toyota starting issue
Submitted: Monday, Sep 17, 2018 at 18:35
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137260
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Nutta
Hi.
My dad has a Toyota Coaster bus, around 1988 model possibly, it has the non turbo 6 cylinder diesel in it and I think it's the 2H.
He has an issue which he had a few years ago which seems to be glow plugs, he's waiting on a new set.
The strange problem is it turns over great but won't start, oddly though if he can get a push it will start within 2-3 metres.
Does anyone have an idea why this happens, he is south and its bloody cold down there at the moment so that probably doesn't help.
Thanks in advance.
Reply By: Bob Y. - Qld - Monday, Sep 17, 2018 at 19:26
Monday, Sep 17, 2018 at 19:26
Last time I drove/worked on a 2H, I didn't have
grey hair!
Your description sounds much like a glow plug problem, Nutta, especially in cold conditions. The 2H also had an EDIC motor on driver's side, which controlled over-injection for cold starts, normal running and engine off. Suggest you get your Dad to
check that the linkage is moving correctly, full forward for starting, then back a few degrees for normal.
2H Starting - 1
2H Starting - 2
Also keep in mind with cold weather, diesel gets very waxy, but this wouldn't be the problem if it roll starts easily.
Bob
AnswerID:
621269
Follow Up By: Nutta - Monday, Sep 17, 2018 at 19:38
Monday, Sep 17, 2018 at 19:38
Thanks Bob.
Dads hopeless with stuff like this and on top of that doesn't know how to use his phone so sending this to him is hopeless, I will try to explain it to him over the phone though, I'm pretty sure he said he's going to try and find a mechanic tomorrow.
Thanks again.
FollowupID:
893789
Reply By: RMD - Monday, Sep 17, 2018 at 22:54
Monday, Sep 17, 2018 at 22:54
Nutta
The problem can be the glowplug supply connection as mentioned above but can also be the relay or it's wiring which either, isn't supplying current to switch on the glowplug relay or the glow plug timer. The timer is temp controlled and the temp sender on the side of the engine may have it's connection disconnected or dirty.
Best to find and
check the connections to it too.
The reason it starts with a bump start is, the engine is then being turned over much faster than with the starter motor and the heat of 22 : 1 compression ratio hasn't had as much time to lose it's heat into the walls of combustion chamber, so effectively it is much hotter than cranking and so fires the injected fuel. Same with any diesel.
AnswerID:
621275
Follow Up By: Nutta - Tuesday, Sep 18, 2018 at 07:06
Tuesday, Sep 18, 2018 at 07:06
Thanks RMD.
FollowupID:
893793
Reply By: Member - DOZER - Wednesday, Sep 19, 2018 at 10:21
Wednesday, Sep 19, 2018 at 10:21
from what you have conveyed, there is an electrical problem with the glow plugs. The system works like this, there is a ecu that controls the relays, it gets info from a water temperature sensor and the alternator running (12v) or stopped (earth). I would start by taking the bus bar off the glow plugs and metering each plug for resistance. They should all be the same resistance. If that is the case,
check for voltage on the bus wire when ignition on and motor cold, volts= the ecu is doing its job, change all plugs, make sure you get the right ones for your coaster, there are different plugs for different market 2h's. If theres no volts,
check the water sensor is sending correct signal to ecu, and regulator on alt is working /charging/etc properly
AnswerID:
621288
Follow Up By: Nutta - Wednesday, Sep 19, 2018 at 16:27
Wednesday, Sep 19, 2018 at 16:27
Thanks Dozer, will pass it on.
FollowupID:
893800
Reply By: Ron N - Wednesday, Sep 19, 2018 at 23:18
Wednesday, Sep 19, 2018 at 23:18
Another thing to look at, besides all the good suggestions above - Diesels need a certain cranking speed to fire up (usually a minimum of around 200RPM), particularly when cold.
If the battery is low on voltage and in poor condition, it may not be supplying enough amperage to reach an adequate starter cranking speed.
Cold oil and a dead cold engine assist in slowing the starter cranking speed.
Another thing to
check is starter cable condition and size.
Battery cable connections must be clean, and earth straps checked for cleanliness and tightness, too.
Not sure about the 2H Toyota, but I own an Isuzu truck that had aluminium starter cables.
The aluminium started to fracture the wiring strands with age and flexing, and this reduced the current flow to the starter, resulting in hard starting.
The cure was replacement with a larger diameter copper cable with finer wire strands, thereby increasing the current-carrying capacity.
When the copper cable was fitted, the engine snapped into life, even on a cold morning, with less than 3 secs starter cranking time.
I've had experiences with trying to start a diesel fitted with 24V electrical system, with just a big single 12V battery.
The engine sounded like it was spinning fast enough - but it wouldn't fire up, even on a warm day - due to the fact it wasn't reaching the critical diesel cranking speed.
Cheers, Ron.
AnswerID:
621296
Reply By: GerryG - Thursday, Sep 20, 2018 at 18:44
Thursday, Sep 20, 2018 at 18:44
My solution might seem primitive but I've had two Coasters (1988 and 1992) have glow plug problems. To
test I've hooked up 24 volts straight to the glow plug bar after disconnecting it from the "computer board" that seems to control the voltage to the plugs.(Coasters run on a 24 Volt system)
Give it about 5 to 8 seconds then see if it will start. In both the above cases it did so I replaced the "computer board" with a $3.50 horn button! So now I decide how cold the engine is and how cold the outside temp. is and give
the horn button what I think is a decent press. (max of around 10 seconds).
Been doing it for years on both vehicles.
AnswerID:
621309
Follow Up By: RMD - Thursday, Sep 20, 2018 at 20:18
Thursday, Sep 20, 2018 at 20:18
Gerry G
You are a smart man. Good on you for diagnosis and positive thinking. Amazing thing the human brain.
FollowupID:
893811
Follow Up By: qldcamper - Monday, Sep 24, 2018 at 08:06
Monday, Sep 24, 2018 at 08:06
That system works
well and is fairly common practice, only down side is that there is no after glow which leads to rough idling for a few seconds when cold and in extreme cold could require a restart, but certainly a more viable option in investing in expensive new parts on an aging vehicle.
FollowupID:
893837
Follow Up By: Allan B (Sunshine Coast) - Monday, Sep 24, 2018 at 09:27
Monday, Sep 24, 2018 at 09:27
.
Yes, I put a pushbutton on the dash of the Troopy when the glow controller failed.
However, it seems to be never needed where I travel.
May be of use in the Alpine region....?
FollowupID:
893839