Page 1 of 1

3Y carby midrange hesitancy

Posted: Mon Nov 23, 2009 9:04 am
by tandanus
Hi,
I'm new here :-) so Hi All !
Folks, my 85 hilux extracab has developed a problem. It started in the recent hot weather - the car starts and runs OK, but then when it had been switched off and restarted it didnt like running at mid-revs (2-3k). If I floored it, it smoothed out. Today is cooler weather, so I wasnt expecting problems, but it still starts and idles fine, but doesnt want to rev unless I floor it, and at high revs it seems OK. I had a good look thru the gregories manual and fixed on the fuel-cut solenoid, but I dont quite understand how to fix it.
Any ideas whats going on?
Thanks
T.

Posted: Mon Nov 23, 2009 10:11 am
by brendanteck
My fuel cut solenoid was giving me grief so I disconnected the 'computer' from it and earther it out. Turnes the solenoid on all the time and cured the problem. +12v is supplied to one side of the solenoid and the other is earthed out by the computer to turn it on.
Another issue I have had is the petrol getting too hot where the pipe goes in front of the head. Caused me a lot of issues in the heat. I made another one that went over the motor.

Posted: Mon Nov 23, 2009 5:36 pm
by dans-paj92
you sure your chokes not getting stuck?
cheers
Dan

Posted: Tue Nov 24, 2009 7:27 am
by tandanus
Well, last night it started, spluttered and after about 10 seconds of not wanting to rev was running fine. Today its going well too. I think the choke is working properly because the idle speed is high until it warms up then it drops back to normal. And wouldnt the top of of the revs be affected by a bad choke? So, the fuel cut solenoid, it needs to earth via the 'computer' in order for the engine to run properly? Where is this 'computer'? And where is it getting inputs from?
T.

Posted: Tue Nov 24, 2009 7:41 am
by brendanteck
In mine the 'computer' is a blue box that hides behind the kick panel in the passenger side footwell. When mine was acting up it only affected it while crusing not under power. I know it gets an input from a pressure sensor that is on the passenger side innerguard and connecter to the carby with a vacume hose but I am not sure about anything else on how it works.
Another thing to check is mine had dirt in these tubes that airated the fuel as it is about to go down the carby ventri. You get to them by taking the top of the carby off and can see them. They look like a brass screw with a hole in the middle. That affected the way mine ran under power as it affects the mixtires.

Posted: Tue Dec 01, 2009 9:14 pm
by Tonka tuff 4x4
also sounds like the jets in the carby are blocking up. get the carby rebuilt or put a 32/36 weber on it, more power and better economy. i had the similar issue with my lux it felt like a fuel blockage (jets) but once the rev's where up it went fine.
you can do the old trick in the book and check if your floats are blocked, change the lead around number 1 to plug 2 and turn the motor over for a few seconds you will hear a poppin sounds if so the jets are blocked. but do not hold the ignition on for to long otherwise the piston may come through the engine block.