Upgrade to 4bbl, what about throttle cable bracket?

[Scott Danforth]

Yeah I don't understand it. I can have the thing perfect in June and then by beginning of August it's like swapping the metering blocks, jets, floats, power valve, pump shot, cam and nozzles never happened. ....I'll supply the beer.

I would love to take a look if your down here sometime and bring the beer..... check your fuel pressure and float height.

I normally buy pre 2004 carbs from Craigslist and marketplace , and then go thru them, including drilling and taping the main body for extra screws to keep the base from warping.

 

[Lou C]

I finally got my act together and put together a fuel pressure checking set up like what was shown in the information on checking your boat's fuel system with the pressure/vacuum gauge, hoses, and all the fittings, what was the most headache was getting the right fittings to mate with the male end of the OEM steel fuel line and then another that goes into the carb inlet, the only place who knew what I needed was (not surprising) a local speed shop (SK Speed in Lindenhurst Long Island), so now I can troubleshoot my fuel problem that has gotten much worse recently and also if I have to replace the pump (a Sierra mechanical that's only about 8 years old) I can check to see if the new Carter one I have as a spare is putting out the right pressure/volume etc. I already used the information in that section for checking vacuum at the pump (fine, 13" hg) and vacuum between the tank and pump (also good, less than 4"hg, actually about 2" of hg).

 

[Scott06]

Agreed I think that explains the variety of experiences/opinions as much as herd mentality lol.

It has to be because none of us are mechanical idiots. Also I think people defintiely migrate to what they like and stick with it, which is normal.

What always amazes me is the shade that Q jets get. When you look at how many different applications it was used on its staggering

 

[Lou C]

And let’s keep in mind about the Qjet
Unlike Holley these were OEM on literally millions of GM vehicles starting in 1966. Yes GM did use Holley on there higher performance models but that was a drop in the bucket. They spanned the range from the short lived Pontiac OHC in-line six to the 454. And they didn’t need constant fiddling at least not the one we had. I cleaned the choke linkage once a year, changed the filter every 30k miles, no rebuilds no leaks no hassles.

You can buy a brand new Holley or Edelbrock anywhere but a good original Quadrajet is VERY rare. And at least 36 years old! I know Edelbrock made them for a while but quit doing so. A shame!

 

[Lou C]

As for my 4160 I’m still wondering if those loose clutch bolts on the secondary metering plate were the source of my troubles! I might just have to try it. It was a shame because I was able to source every single part needed to make it fit perfect on the OMC 4.3; accel lever adapter, OEM fuel line and throttle cable mount, even the special adapter (spread bore to square bore) used by OMC & Volvo. Both OMC & Volvo switched to this exact 4160 in 1990 after GM quit building Qjets.

 

[Pmt133]

I would love to take a look if your down here sometime and bring the beer..... check your fuel pressure and float height.

I normally buy pre 2004 carbs from Craigslist and marketplace , and then go thru them, including drilling and taping the main body for extra screws to keep the base from warping.

View attachment 418895

It originally had one of those adjustable holley mechanical fuel pumps on it... that thing never acted right. Went back to an oem and have a stable... admittedly every time I've checked it... 6psi. The floats were adjusted via the sight hole.

I have 2 things I want to check. I suspect, the cam follower on the accelerator pump may be tweaked. The timing on the pump shot, regardless of cam or adjustment, always seems too late. Which leads me into thinking the entire linkage arm layout may be tweaked. It's the only thing I haven't gone through on it with a fine tooth comb.

And I think I'll add those extra screws too for good measure. I also still need to tap it for air bleeds so I'll do both at the same time.

 

[Scott Danforth]

#12 screws