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GQ Y60 TB42s (Carb) stuttering, spluttering rough running and idle

Posted: 21 Nov 2022 21:54
by symmetry4wd
Hi Guys,

So I recently removed my TB42 intake with carb to replace all heater hose fittings, heater hoses, fuel hoses, and any vacuum lines that were suspect.

After putting everything back together, my engine won't idle well, was first over-fuelling couldn't hold a steady idle, and was spluttering & stuttering and wanting to die.
With this in mind, I realised I could have by mistake adjusted the idle mixture screw while the intake/carb was off the car. So I set about trying to get a could idle by adjusting the mixture screw, this didn't help anything.
I then had a look at the vacuum lines, and after much searching I made sure all vacuum lines were at least to my knowledge all in their right places.
Still idles and runs like before.

I didn't touch anything else other than the mentioned heater components. How did this issue happen?!?!?!?
I didn't mess with the timing, or distributer at all, not the leads, plugs anything like that, and the car ran perfectly well/fine before I started and finished my work on the cooling system.
So What could I have done to cause this issue??


Next I am going to look if I bent the float arm, but don't know how I would have done that.....

Also I noticed at one point that there was some fuel in the vacuum lines, I think from flooding the carb/engine from all the starting trying to figure stuff out. could this mean anything?

Any advice is appreciated, this is really frustrating me now :thumbdown: :thumbdown: :thumbdown:

Re: GQ Y60 TB42s (Carb) stuttering, spluttering rough running and idle

Posted: 21 Nov 2022 22:12
by symmetry4wd
btw this is what the idle mixture screw tip looks like, I just wanted to inspect it to make sure its not damaged, does this look fine??
IMG_8241.JPG

Re: GQ Y60 TB42s (Carb) stuttering, spluttering rough running and idle

Posted: 21 Nov 2022 22:27
by symmetry4wd
It also seems like adjusting the idle mixture screw does nothing while the car is idling!?

Re: GQ Y60 TB42s (Carb) stuttering, spluttering rough running and idle

Posted: 22 Nov 2022 06:39
by Peter Connan
Is the idle cut-off solenoid working?
You should be able to.feel it click if somebody switches the ignition on and off while you touch it.

I haven't looked at an idle screw in several years. That one looks a little blunt but I could easily be wrong. Either way, that should not give you zero response.
Is the hole clear?

Re: GQ Y60 TB42s (Carb) stuttering, spluttering rough running and idle

Posted: 23 Nov 2022 21:30
by symmetry4wd
So,

After a lot of thinking, checking etc etc seems like I've sorted the issue.

Changed out the plugs, to new NGK BPR5ES plugs, and the TB42 is running well!

The old ones, with fiddling with the carb too much, and whatever else was going on with the over fueling seemed to have fouled the plugs:
IMG_8262.JPG
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I did the carb idle mixture adjustment procedure as followed here, and no matter what, the engine wouldn't run smoothly, which led me to changing the plugs to eliminate that, and it worked.
IMG_8253.JPG
IMG_8251.JPG
IMG_8252.JPG
also made sure the vacuum lines all were correctly fitted in the right places as per here:
IMG_8249.JPG
IMG_8248.JPG
IMG_8247.JPG
Now a little more carb tweaking and the engine should run perfect :thumbup: :thumbup:

Any recommendations on someone familiar with carb tuning and more specifically the TB42 Nikki carb in cape town?

Re: GQ Y60 TB42s (Carb) stuttering, spluttering rough running and idle

Posted: 24 Nov 2022 03:15
by Tinus lotz
Guys understanding carbs is a problem ...ant does it the best up here .glad to see you are sorting your gq property