Quadrajet Problem Solving > Diagnose a Quadrajet carburetor problem

Olds 403, Qjet might be too lean. Help me please.

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hunter_alexander:
Ok, So here are the specs on the build of my car.

1987 Cutlass,

403 stock bottom end.
#6 big valve heads.
Compression is 9.8 to 1
R46sx plugs
RPM intake
17059253 Qjet off 403, rebuilt .073 primaries, .052 secondaries. No choke. High flow needle and seat, Float level at 13/32. Everything should be adjusted correctly.
Rebuilt Stock HEI, adjustable vacumm advance can adjusted all the way to limit the vacumm advance, stock weights, red springs, MSD module with rev limiter.

Timing set at 18* initial - all in at 3k and 35*.
Cam specs as follows:
Ultradyne cam - part number 318000 -
duration at .050: intake 221 exhaust 232
Lobe lift: Intake .3027 exhaust .3273
Separation: 109
Gross valve lift: intake .484 exhaust .524

Aluminum 4 core champion radiator. Fan shroud, all air deflectors in place to funnel air through radiator.
160* milodon tstat. Tested working correctly.
Original 5 blade 307 fan with thermal clutch.

10w30 brad penn oil. 40PSI hot at idle.

2004r, no lockup yet.
8.5 rear 3:73 gears.

The car is running too hot. Thinking its too lean. I have done adjusted  the carb, used the tip in method and it picks up rpm.

Anyone help me determine if the carb is too lean?

Thanks

Craig

hunter_alexander:
Couple other guys mentioned that I should go to #75 jets to fatten her up. I am gonna order the parts from cliff (been ordering all my parts from him, good stuff :))

How do you know when you need to change the rods too? Should I just go up two jet sizes?

Thanks.

Schurkey:

--- Quote from: hunter_alexander on May 21, 2011, 01:33:28 PM ---
Rebuilt Stock HEI, adjustable vacumm advance can adjusted all the way to limit the vacumm advance,
Timing set at 18* initial - all in at 3k and 35*.
--- End quote ---
How much vacuum advance?  Ported or manifold vacuum?  Can you add more without ping?

I'd be looking for an appropriate 7-blade fan; unless it's hot at higher speed and not running hot at idle and cruise.  Are you sure the fan clutch is actually engaging?

Cliff Ruggles:
What primary metering rods?....Cliff

hunter_alexander:
Ill have to pull the carb apart to check the rods.

I am using ported carb for the vacuum advance, 14*. It runs hot, 220* on the highway at 65mph. Doesnt matter what I do with the timing, it keeps pinging. Defintely at this point I am thinking its lean.

The fan works great. Doesnt seem to be running as hot just idling. More when driving it around.

Cliff, I will be calling here in a bit to order what I need.

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