I had disassembled my QJ and sent the throttle plate for rebuild, the main body and the air horn for deep clean and plating, various rods, flaps, etc for cleaning and plating as well. I purchased the rebuild kit for this carb #, a set of new fasteners, new rods, and other misc items. Came to about $220
It as been sitting waiting for me to get back to it. Here is the rebuild kit:
Here are some tools I have acquired which really help. Drill bits from 40 to 80, digital caliper and the carb stand in a prior picture.
A pic of the parts safely stored in the plastic tub ($5). Subsystem parts are inside of zip lock bags to keep the parts together:
(Each of the carbs are stored in their own similar tub to keep their parts together)
In the course of working on this, I found that this particular carb is NOT the best one to work with. Computer linked carbs have a TPS and those are not good at all. My carb is the next one up the list. It is not computer connected, but does have a Mixture Control Solenoid (MCS) which reduces the amount of fuel which is pumped into the carb when the engine is warm. They only used this carb in 1985 and 1986, before adding the TPS connected to the computer. I don't need this MCS, therefore I can fill the small bowl where the solenoid fits with LEAD to disable that feature. Then the carb will be just fine after the Higher Performance mods are done.
Cliff has come up with a set of RECIPES (3 main ones actually), in increasing aggressiveness depending on the aggressiveness of the engine (CAM, compression, gears, etc). I am modifying my carb to recipe number 1. The following list contains the various attributes of the carb that I measured for what they are now and what RECIPE 1 calls for:
Quadrajet #
17085231 1825 HMB
This QJ has already been sent in to Cliff for base brass bushings, and plate cleanup and plating.
Ordered its kit as well, and some more parts, like NEW screw kit, etc
Measured the following:
Attribute------------------------------------Measured Value----------------------Recipe 1
Idle Tube ----------------------------------- .036 ------------------------------- .036
Idle Channel Restrictor (DCR)-------------- .055 < size < .059 --------------- .046
Lower idle air bleed -----------------------.070 -------------------------------- .070
Upper idle air bleed (main body) ------ .067 < size < .070 ----------------.067 to .070
Accelerator pump discharge holes ----.026 --------------------------------- .026 to .028
Main air bleed (MAB) (air horn) --------- .082 < size < .088 ---------------- .070
Idle bypass air -------------------------- .055
Mixture screw holes --------------------- .055 --(+.015 to .020)------------- .070
Main Jet ----------------------------------- .067 < size < .070 ----------------.073 (in kit)
Primary rod ------------------------------ .044 -------------------------------- .044
Fuel inlet seat --------------------------- .128 < size=.130 < .136 ---------.135
Secondary POE well restriction -------.039 --------------------------------- .032 to .038
Secondary POE restriction ------------ .052 -------------------------------- .052 to .055
Secondary tube restriction ------------ .025 -------------------------------- .036
Secondary hanger --------------------- N----------------------------------- K or higher
Secondary metering rods -------------.0667 CL ------------------------- .045-.055 (DA in kit)
Another good website for QJ parts info (rods and hangers) is:
http://www.carburetion.com/rodshang.asp
Summary mods I will make:
1) I will enlarge the mixture hole to .090
2) Install the 73 jet (was .69 or so - lean)
3) Install the .135 fuel inlet seat (was .110 - low flow)
4) Install the K hanger (more fuel) (was N - also lean hanger)
5) Install the DA rods (more rich) (was CL - the leanest rod possible)
6) Install the primary rods that were original
and leave the rest alone for now.
Cliff's DD is a 1974 GTO with his QJ, generating 600+ HP, and 11.64/11.66 sec 1/4 mile
And a good video for determining misc problems with a QJ:
Without cliffs book, I don't think I would have tackled the QJ. It gives the history of the QJ, how it works, how to identify the various versions of the carb, which are good units, which are bad, how each system can be modified to improve operation, and where its weaknesses and strengths are. Understanding the operation of a system is important in being able to modify that system correctly. Great book. Have read it 7+ times now.
I know this is a Toyota forum, but for those like me who have installed a SBC with a carb - I know there are others out there - taking care of your QJ becomes vital, at least to me and hopefully for others.
Lots of videos on youtube on the QJ, some good, some not good, but I have found Cliff to really have the answers.
AND I found out (johnny late here) that there are intake manifolds that allow one to put carbs on the 5.3L engine - yeah, sounds like fun. AND true, I am a bit weird, but this hobby allows one to do things a bit different and in a TLC at that.
If I had known that fact (carb on a 5.3L and the 5.3L existing) I would have done the 5.3L with a carb instead of my Gen I SBC - but oh what the tuition has bought me in skills and knowledge and a smaller wallet.
The 5.3L would have been MUCH cheaper: $2000 for the 5.3L and a carb vs $7500 for the Gen I engine and carb.
My future FJ40 will have a 5.3L with a Quadrajet Carb!
Video of a LS1 with a QJ:
UPDATE: I remembered a friend who casts lead bullets. He has agreed to fill the small void in my main body of the carb. Once done, I can then proceed to re-assemble.
dougbert