Secondary metering rod size?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

spanky55amg

I'll give u $5, a hardy handshake, & 5 fish sticks
Joined
Jun 6, 2017
Posts
819
Reaction score
212
Location
Dallas, TX
First Name
Spanky
Truck Year
1984
Truck Model
C10 Short Fleet
Engine Size
V8
so 12 pages in and Im just getting to this. Here is my background, sounds like you are having the same issues as me.

I have a rebuilt qjet, you can find the thread somewhere of me bitching... multiple threads. I have looked it myself and my secondaries are DR's. I have adjusted this thing 6 ways from Sunday. Its not ignition... how do I know... I pulled the vacuum line for advance and mine is set to 4 deg base timing. In 4th gear, down the highway, under load, i get backfires, hesitation, and a whole bunch of nonsense.

I have tried 91 octane at 4 deg timing and thats not it. At cruise the qjet, and someone should correct me, but i believe, that the qjet is using the idle circuit. If I am at a dead stop and punch the throttle, no back fires, and the secondaries open up just fine. So if going down the highway and it acts up. I pull over. Stop. Wait for traffic and WOT that som-beech through 1st and 2nd and it seems to clear up for my 20 miles drive.

I thought it was the choke, and that does clear up some of my issues. Its disconnected right now because it wasnt opening up correctly or I am running so rich, it chokes it too much. My idle mixture screws are out three full turns. Any less than that, and I have issues. Now with it out 3 turns, no issues.

I did put a Delphi fuel pump on about 4 months ago. I was having other issues which the fuel pump cleaned up. But I know its putting out 10 psi. So when the bowl is full, its getting extra full and my thinking is that when I go WOT and clean it out from a dead stop, it removes and empties the totally full bowl.



This is my theory. I have checked everything else but I know the fuel pump is putting out 10 psi which is more than it should put out. The qjet wants 4.5-6 psi. This is becoming a big issue from aftermarket fuel pumps, even if they are Delphi or AC Delco (same thing).

Here, check this out.

https://www.google.com/search?q=che...rome..69i57.8395j0j7&sourceid=chrome&ie=UTF-8
 

3504boltmain

Full Access Member
Joined
Jan 1, 2018
Posts
122
Reaction score
39
Location
Virginia
First Name
Trent
Truck Year
1985
Truck Model
C30
Engine Size
5.7l
so 12 pages in and Im just getting to this. Here is my background, sounds like you are having the same issues as me.

I have a rebuilt qjet, you can find the thread somewhere of me bitching... multiple threads. I have looked it myself and my secondaries are DR's. I have adjusted this thing 6 ways from Sunday. Its not ignition... how do I know... I pulled the vacuum line for advance and mine is set to 4 deg base timing. In 4th gear, down the highway, under load, i get backfires, hesitation, and a whole bunch of nonsense.

I have tried 91 octane at 4 deg timing and thats not it. At cruise the qjet, and someone should correct me, but i believe, that the qjet is using the idle circuit. If I am at a dead stop and punch the throttle, no back fires, and the secondaries open up just fine. So if going down the highway and it acts up. I pull over. Stop. Wait for traffic and WOT that som-beech through 1st and 2nd and it seems to clear up for my 20 miles drive.

I thought it was the choke, and that does clear up some of my issues. Its disconnected right now because it wasnt opening up correctly or I am running so rich, it chokes it too much. My idle mixture screws are out three full turns. Any less than that, and I have issues. Now with it out 3 turns, no issues.

I did put a Delphi fuel pump on about 4 months ago. I was having other issues which the fuel pump cleaned up. But I know its putting out 10 psi. So when the bowl is full, its getting extra full and my thinking is that when I go WOT and clean it out from a dead stop, it removes and empties the totally full bowl.



This is my theory. I have checked everything else but I know the fuel pump is putting out 10 psi which is more than it should put out. The qjet wants 4.5-6 psi. This is becoming a big issue from aftermarket fuel pumps, even if they are Delphi or AC Delco (same thing).


Here, check this out.

https://www.google.com/search?q=che...rome..69i57.8395j0j7&sourceid=chrome&ie=UTF-8
I haven't checked out the link yet, but I'm about to... I think the previous pump that was on there was pretty old... I don't know the brand of the one I put on there. Thanks for the heads up. I will do a flow test on the pump. I heard carbs had less flow than fuel injection engines... 6psi being very high for a carburetor??? cool though... Ok and DP rods... As far as I've read, you are the first person to answer the VERY FIRST QUESTION I had. I thank you for that, and will look into what size a DP rod is... The CN rods I think have a short throw at .057 thou... Much appreciated your input... Yoda am I?
 

3504boltmain

Full Access Member
Joined
Jan 1, 2018
Posts
122
Reaction score
39
Location
Virginia
First Name
Trent
Truck Year
1985
Truck Model
C30
Engine Size
5.7l
I know I'm going off in a different direction here, but could this be valve float? I listened to a couple videos on this, and it sounds very similar to what I've got going on.

I just rechecked the compression (actually did it right this time) and it seems spot on... A little low but all readings between 160 and 170. Number one was, 160 #2 was 170, and all others were very near 165. With one exception... I absolutely could not get the fitting and hose into cylinder 6 at all... Period. The header was interfering. I tried the fitting first, then the hose (the fitting went in, but the hose couldn't be threaded into the fitting). I tried the hose and fitting. I tried the hose partially screwed into the fitting... The closest I got was with the hose partially screwed into the fitting... It started to go in, but I knew it was to good to be true... I backed the hose and fitting out and it obviously was cross threading.

Anyway, with that thermal gun reading cold, but slightly hotter downstream on number one exhaust, and a slightly low compression in the same... I would consider that there may be an issue in there. What I don't know, is that if this is a "valve float" issue, is one valve going to cause this much hesitation (it's more like a surging than anything (and I have heard that valve float can feel like a rev limiter))? Or is this something that I should believe that all the valves or most of the valves are experiencing? I kind of want to take a paint marker to each spring and mark them in their current location, drive the truck until it surges like the tard it is, and pull the valve covers back off and peek around.

I know I might be way off track, but I am trying. I can't wrap my head around the fact that this thing will redline in the driveway (meaning, I would guess this gets up to around 5 or 6k rpm and I dare not push it any further), but it will not push over 4k rpm driving down the road... Well, actually, the surging happens not at a specific rpm... it's kind of strange actually... It happens in every gear, but it seems to happen when... and maybe I'm wrong... but when a certain amount of power is needed. It simply will not do it.

spanky55amg Our issues are kind of similar, but I don't get a "second chance" kind of response like you did with your truck. I can try to snap the throttle or slowly get into it... Either way yields the same results... Even if I shut her off, or try anything else... I also looked at "DR" (Not DP as I first responded) rods, and "CN" rods are .003" different I believe... No big difference there, so I can look at different rods, but I don't see that being my issue...

Also, I think somehow I am running rich. I've got backfire and my plugs are all very sooty. I will plan to lean the truck out, maybe screw with the timing. But I couldn't say the surging is caused by a rich mixture... Or?

Jokers are expected and welcome.
 

spanky55amg

I'll give u $5, a hardy handshake, & 5 fish sticks
Joined
Jun 6, 2017
Posts
819
Reaction score
212
Location
Dallas, TX
First Name
Spanky
Truck Year
1984
Truck Model
C10 Short Fleet
Engine Size
V8
Set your idle to 500 in gear .idle mixture at the biggest vacuum, something around 1.5 turns each. And test your fuel pressure .
 

Honky Kong jr

Super Sarcastic Man
Joined
Jun 14, 2016
Posts
14,968
Reaction score
9,828
Location
Denver,PA
First Name
J-me
Truck Year
87
Truck Model
V10
Engine Size
Lil BB 407
Set your idle to 500 in gear .idle mixture at the biggest vacuum, something around 1.5 turns each. And test your fuel pressure .
LMMFAO not your post or your info just the mental picture it produced.
 

spanky55amg

I'll give u $5, a hardy handshake, & 5 fish sticks
Joined
Jun 6, 2017
Posts
819
Reaction score
212
Location
Dallas, TX
First Name
Spanky
Truck Year
1984
Truck Model
C10 Short Fleet
Engine Size
V8
LMMFAO not your post or your info just the mental picture it produced.

I dont want to know what you are mentally picturing about me and a truck... weirdo. haha
 

Honky Kong jr

Super Sarcastic Man
Joined
Jun 14, 2016
Posts
14,968
Reaction score
9,828
Location
Denver,PA
First Name
J-me
Truck Year
87
Truck Model
V10
Engine Size
Lil BB 407
I dont want to know what you are mentally picturing about me and a truck... weirdo. haha
No him standing in front of it with the truck in gear setting the idle and running himself over lol
 

spanky55amg

I'll give u $5, a hardy handshake, & 5 fish sticks
Joined
Jun 6, 2017
Posts
819
Reaction score
212
Location
Dallas, TX
First Name
Spanky
Truck Year
1984
Truck Model
C10 Short Fleet
Engine Size
V8
No him standing in front of it with the truck in gear setting the idle and running himself over lol

Well... good catch. I would have figured that no one would have actually stood in front of their truck in gear. lmfao.
 

spanky55amg

I'll give u $5, a hardy handshake, & 5 fish sticks
Joined
Jun 6, 2017
Posts
819
Reaction score
212
Location
Dallas, TX
First Name
Spanky
Truck Year
1984
Truck Model
C10 Short Fleet
Engine Size
V8
Rumor has it......
Nah, I didnt read. Ain't nobody got time for that ****.... well, I dont. Work is wearing me down to the bone. Which is why yall havent seen me.
 

Honky Kong jr

Super Sarcastic Man
Joined
Jun 14, 2016
Posts
14,968
Reaction score
9,828
Location
Denver,PA
First Name
J-me
Truck Year
87
Truck Model
V10
Engine Size
Lil BB 407
Not meaning to interrupt your OT discussion (it has been pretty funny).... However, man that was one kick ass link. The amount of info there is just insane. Cool stuff...
Thanks much!

Hey @3504boltmain , if you scroll WAY, WAY down, the dude walks you through step by step on setting/checking everything on the Quadrapuke. Just me, but I'd get a Holley.... Lol.

(And check the cam)
Get it right Slobberjet
 

Forum statistics

Threads
44,173
Posts
950,868
Members
36,288
Latest member
brentjo
Top