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Ted
8th April 2011, 10:04 AM
Hi guys,

Some help needed, every time I start the engine in the morning it really doesn't enjoy the cold start. Revs will be really low and struggling not to stall, it'll run at say 200 revs or less until the temperature comes up.
Which has me thinking there's something wrong with the automatic choke, however when the engine begins to warm the revs start to increase and once warm she idles perfectly and purs at me again running smoothly at exactly 650 revs and never misses a beat!

What gives?
Cheers,

Ted

Bigrig
8th April 2011, 10:23 AM
Hi guys,

Some help needed, every time I start the engine in the morning it really doesn't enjoy the cold start. Revs will be really low and struggling not to stall, it'll run at say 200 revs or less until the temperature comes up.
Which has me thinking there's something wrong with the automatic choke, however when the engine begins to warm the revs start to increase and once warm she idles perfectly and purs at me again running smoothly at exactly 650 revs and never misses a beat!

What gives?
Cheers,

Ted

Have you cleaned the MAF sensor? Something simple to try, but mine was doing the same after the last trip, and ended up giving the sensor a hit with some CRC mass air flow spray, and hey presto!

HippoNZ
8th April 2011, 10:52 AM
Mines just like that too, except I have a manual choke which I pull out until warm otherwise the truck shakes like Sh!t or stalls lol I possibly thought the glow plugs arn't as good as they use to be and may need replacing, It's on the "I'll get round to it list" haha
If you fix yours please post the solution

Cheers
Brett

growler2058
8th April 2011, 11:02 AM
Mines just like that too, except I have a manual choke which I pull out until warm otherwise the truck shakes like Sh!t or stalls lol I possibly thought the glow plugs arn't as good as they use to be and may need replacing, It's on the "I'll get round to it list" haha
If you fix yours please post the solution

Cheers
Brett
Is that TD42? mine was doin the same but started running a fuel additive to clean the injectors and its fine, on a real cold morn it'll shake and rock n roll a bit without help from the "choke" but hell of a lot better than it was

Ted
8th April 2011, 12:39 PM
Have been looking around a bit and indeed its the automatic choke stuck open (Choke off)
Take off the air filter housing and you can see if the "butterfly" is stuck open or closed.
Will wait for the car to cool down again and will give it another try and see if it closes, if not I'm pretty sure its dodgy and I'll just turn it into a manual choke. I've recently changed all my spark plugs etc, so I reckon its a reasonably easy fix!
Cheers though fella's!

HippoNZ
8th April 2011, 12:58 PM
Is that TD42? mine was doin the same but started running a fuel additive to clean the injectors and its fine, on a real cold morn it'll shake and rock n roll a bit without help from the "choke" but hell of a lot better than it was

Sure is a TD42, I ran a fuel additive last week on trip I did, still on the same tank of fuel. You reckon I should keep doing this for a while to see if it cleans out the injectors? TD42's are a big solid motor so I expect a bit of shake but you could almost charge 5yro for a roller coaster ride! LMAO nah shes not that bad but not that good either. cheers growler

YNOT
8th April 2011, 01:03 PM
Ted, when you do a cold start do you pump the accelerator once before you start the engine? A lot of automatic chokes need that to reset them to the start position.

Tony

Ted
8th April 2011, 02:07 PM
Yeah mate i always give the throttle a little kick when i turn the ignition, heard that little nugget of info before, cheers tony

YNOT
8th April 2011, 02:34 PM
When the engine is cold remove the air cleaner housing and have a look down the top of the carby, the choke butterfly should be closed. You may need to open the throttle once to release it to the closed position. If the choke butterfly is not closed have a look at the choke coil housing on the outside of the carby, there should be lines that line up between the choke housing and the carby body.
If it's lined up but still stuck open then it could be either a siezed butterfly shaft or no power to the choke coil.

Tony

Ted
8th April 2011, 03:27 PM
Hey tony,
given it a once over like you said mate, everything is connected up properly, the carby and all lines up the way it should be (had this checked out by a mechanic)
However the butterfly is stuck half open, with the engine running i gave it a little push to close the choke butterfly and the engine shut off.
When i turn the key again to start it, it returns to half open position. It wont stay completely open nor will it stay completely shut either, any ideas?

YNOT
8th April 2011, 03:52 PM
If the choke butterfly can be moved as you say then the shaft is not seized.
Have you checked the choke butterfly position when the engine is completely cold?

Tony

Ted
8th April 2011, 04:04 PM
I did this quick check when the engine was moderately cold, I'll give it a quick check in the morning. I've got a feeling its permanently stuck in the half open position regardless of the temperature...

Update:
Given it another quick check and the choke butterfly moves around normally until I touch/pump the accelerator after which it gets stuck in half open position and have to push it hard til it clicks and then it moves freely again, touch the accelerator again and its stuck in half open again. Spring busted or something?
Would installing a manual choke fix this problem permanently too?

Cheers,

Ted

Ted
10th April 2011, 04:43 PM
just a quick bump,
you still out there tony? :D

YNOT
10th April 2011, 04:45 PM
I'm here.

Tony

Silver
21st April 2011, 01:27 AM
I'd be interested to know what manual choke system works for the TB42, as mine gives problems in Brisvegas, and even more when I go to the New England area of NSW where it hits -11C.

I have marked the butterfly adjustment so I have reference point to come back to, and rotated the external housing to get the butterfly to close earlier or later. However I think I also need to pay attention to the instructions for fast idle too???

I used to regularly give it all a good squirt with carby cleaner but have been a bit slack lately. Mine must be coming off a bit too soon as it leans out and backfires through carby when it's gone a k or so from cold. Not a fuel filter issue as it responds well to a boot full up a hill when warmed up.

Mechanic mate over the road also has TB42, and in common with other cars he has owned over the years, has removed the choke entirely.

Ted
21st April 2011, 05:33 PM
Yeah mate I've had a mechanic look at mine and its not the choke, which works perfectly fine rather its carby problems for me.
Previous owner I bought the car from hadn't connected the carby and pollution lines properly so I've just connected em back up but am not sure if this has been done properly.
Am kind of hoping there's someone with a 1990's model GQ with a TB42 Carby so I can see how they're supposed to connect up so I can just copy that, AND living near Newcastle NSW...