Carby problems tb42

[jamied]

Ok so today I pulled the carby off my gq and gave it a good clean out. I pulled it all apart and replaced all the gaskets as I went. When I put it all together and fired it up there is something wrong. It idles either way too fast or a little too slow depending on the position of the fast idle cam however adjusting the idle speed screw had no effect. I have been playing around with it all day but just can't work out what I've done wrong

[Robo]

Does it drive any different?.
Not slowing down with engine breaking as it should do ?.

[jamied]

I haven't actually tried driving it since. It seems yo rev ok through the rev range though

[Robo]

Tuning the carby over the yrs and then cleaning it out it should require different adjustment, fair enough.
One would assume linkages are back in there original positions.
As they came off ?, and no alterations made to any of the the links tab ends, bends, and placement etc
Any link bushing is in correct position and or way round ?.
Linkage springs are correctly positioned ?.

Whats the revs while choke is engaged ?.
1900 revs, these things idle fast cold.
so if cold setting is to low the hot setting should reflect that also and be to low also.
Whats going on looking at that, maybe its simply idle is set to low !! .

Did you clean out the deceleration device also? (alloy block, rocker cover side of carby)
it could require adjustment if vehicle doesn't preform as required on deceleration.
it's a emission device but will/can effect carb performance some what.

Vacume hoses are in correct position and no splits?.
The twin vac hoses that run from air box to t-pce near mixture screw, 1 has a reducer inside it, fairly sure it's in the front one.check vac schematic to confirm that.
It's in correct position and cleaned out?.
Choke is installed correctly.
Top of black choke spring housing has a small mark to align with a mark on it's mating surface housing.
aligning these is a default setting.
Black has arrows lean and rich for a visual setting so you cant go wrong, they think of every-thing Mr nissan.

Hope this helps.
cheers

[jamied]

Thanks. I didn't touch the de acceleration device, mainly because the screws were tight and I was just damaging the screw heads. All the vacuum hoses are deffinatly as they were. Not to say there were not wrong in the first place. A lot coming from near the idle screw have been blocked off. I'm coming to the conclusion it's to do with choke and or fast idle cam. I pulled the cap off the choke and it came back to normal. also if I manually move the fast idle cam it comes good but as soon as I touch the throttle it catches on the first notch which Is obviously why it's idling high. I made sure I put it on the way it came off as I took reference photo to make sure however something must be wrong here. I'm not very experienced with these things ( I kinda learn as I go) so I'm not too familiar with exactly how it should opperate

[jamied]

When should the fast idle cam be activated and when should it not?? Got it back to normal do I took it for a spin around the block and when I got back the idle was on 1000 rpm and fast idle cam was on the first notch