Help Needed - extremely rich

Need some help here please!

Just got the car running starts right up and idles no issues but the car is running extremely rich to the point I can only have it run for like 15 seconds before my eyes are watering in the garage.

Engine is Lq4, 243 heads that have been worked, vacuum at idle is around 10, cam specs Comp LS Hydraulic Roller, Xtreme Energy LSG lobe 13119int and 13121 exhaust. intake 283' @ 0.002/234'@0.050 0.602lift (stock rocker). Exhaust 291' @ 0.002/242'@0.050 0.605'. Cam was ground with 112' split and 4' advanced.

Pulled all the plugs front 4 seem to be soaked and the rear 4 are fowled. I am running a pro systems carb specs below ( I have jetted down to 70 in the front and changed power valve to 6.5 from 5.5. I know it should be half of the vacuum reading but I don't have a 5PV I will try a 4.5 tonight.

I have yet to hook up laptop to the MSD 6014 but have I have tried all the built in timing selectors on the box with no difference.

any ideas? (carb is also brand new)

Have you messed with the idle mixture screws?

Andrew

float level? ignition advance? Also check that the idle slot is not uncovered allowing enough signal to the boosters

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Originally Posted by btmatt

float level? ignition advance? Also check that the idle slot is not uncovered allowing enough signal to the boosters

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Float level is at the bottom level of the sight glasses I lowered it. Running 13 degrees of timing right now at idle. Truck HO setting on the 6014 box.

It is not the power valve, all of them are below the idle vacuum. The 6.5 should have been fine.

Jets do not come into play until you open the throttle.

Check the idle transfer slots in the carb as mentioned above. When you add a big cam, it requires a higher idle speed... as you open the idle screw it exposes the fuel transfer slot which pulls in a ton of fuel at idle.

An easy fix is to open the secondary stop screw, which allows you to reduce the primary idle screw setting. I think the carb you have, has a top side secondary setting. Open the secondary side about 1/2 turn & reset your idle. Repeat as necessary.

Just lower the injector pulse width at idle :-P

The more I deal with fuel injection, the less I like carbs.

I completely misunderstood this thread title... [emoji2957]

Is this a new engine rebuild? After break in period plugs will clean up. And then you can really start tuning. The AIr/Fuel gauges help out.

Most SB chevys We’v had good luck starting the Jets off at 65prim/70 sec.

Contacted Patrick at Pro systems to see if he could help. Im only getting like 5'' of vacuum at idle which concerns me as I think I would have been closer to 10-12 with my cam. I put 5.5 PV back in and left the smaller 70 jets.

My float bowl is showing fuel at the very bottom, while idling fuel is pouring out of the primary boosters, fuel PSI is 5-6. I even tried turning in the mixture screws until they are completely closed and the car didn't die.

Starts, runs idles... just extremely rich. Plugs are mangled and raw fuel out the exhaust.

I checked for spark and all cylinders are firing, I also did a compression test and all is well across the board.

Im stumped.

Time to try a different carb.

It is pulling fuel from the boosters because the primary plates are too far open.... Do what I said in a previous post.

You also said it had 10" vac at idle, now you say 5" ????