Carb has too much idle hole drilled?

PKRWUD · 10-21-2004, 02:51 PM

Quote:

Originally Posted by crazypete

I'll go in tonight and pull the carb and threadloc the stripped bolts' tap. It still has threads in it, but you can see the stud rise as the bolt is tightened so they dont hold much. The thread-loc had worked before to hold it down and allow pretty good tighening to take place but I pulled/replaced the carb so much in the last 2 weeks that it came loose again.

Dude. What you need to do is fix it right the first time. Either drill it out and put in a heli-coil, or get an oversized stud. Heli-coil would be my choice.

Quote:

Originally Posted by crazypete

Quick question for tonight's tuning session: Can a 4 corner idle carb be run like a 2 corner idle carb (put the 2 rear screws in and adjust from the front).

Sure. 4 corner idle is just for fine-tuning engines with a lot of cam. After you get it set with the front, you can back out the back ones in small increments until the vacuum gauge stops rising, and then turn them in 1/8th of a turn. Then reset the idle speed.

Quote:

Originally Posted by crazypete

I found an old post with the intake trick. 3-7 psi vacuum while cranking with throttle blades shut. Will do.

Make sure you block off every vacuum line going to the intake.

crazypete · 10-21-2004, 07:26 PM

AHA!

I did the intake test and I got a flickering 0-1 psi(?). There is one and only one vacuum stem and that had the guage on it (slid onto a hose with a clamp) so I guess it is the intake. It must be an intenal leak because I rtv'ed around the intake top earlier and rtv'ed the carb base so it was not leaking from there either. The carb was fully closed.

As long as I will be pulling the intake, I'll heli-coil that annoying stripped thread. Well, at least I know I did the head/intake port correctly and the rockers were a good purchase. That low cylinder pressure still bugs me but well let the "seat of the pants" decide how this project turned out.

88fivepointoh · 10-22-2004, 09:18 AM

OK, One question, The casing is aluminum, water will cause it to corrode quickly especially if boiled. I did this on my 87 Camaro once to clean it and destryed the Carb.. Was a great excuse for a new one however.. hehehe.. Also RTV, BAD!!! on carbs, clogs everything up. I am leary on putting expoxy on the Throttle Blades. it it falls down there and makes its way in the cylinder, you could cause danmages. weld them closed would be best and grind them down smooth...

crazypete · 10-22-2004, 10:14 AM

I'm not sure about the corrosion thing since the carb is aluminum after all BUT after cleaning step number 2, there was white powdery stuff on everything which could have been corroded aluminum. But, being a stubborn SOB, I refuse to write off the avenger since it was my first carb. I will boil and soak and do whatever necessary to clean her out. It was probably fine seeing how my intake probably has an internal leak.

The bolt threads are loc-tited (is that epoxy? Sure doesnt look like it). In all honesty, the screws could hold themselves in without extra help but it seemed like quick and dirty insurance so I dont have little screw heads in the intake.

I will de-rtv the carb when putting the intake back on.

Rev · 10-22-2004, 07:53 PM

Pretty sure that JB Weld is gas proof. Soldering the holes closed would probably work well too and could be smoothed off pretty easily. Actual welding might warp the butterflies with the heat and that would cause all kinds of problems.

Rev

crazypete · 10-24-2004, 07:06 PM

Victory!

Got it! It was the intake. I pulled it and got some good felpro gaskets and RTV'ed like crazy and torqued the intake down to specs.....then I saw that the stupid cork end gaskets had been ejected so I RTV'ed the ends shut and WHAM! It started up! What a difference.

I was using 5-6 full turns of all four idle screws to try and get it to idle.... now, I am using 1.5 turns of each of the 2 fronts only and it idles like a charm! It can actually idle lean! The avenger never was able to idle less than med rich. That black smoke mentioned before was actually burning oil from the cylinders I fogged. I know cause there's a pool of grey burnt oil behind the car.

I ran it for 30 mins to clear out the cylinders and the exhaust and apart from a header that refuses to accept it's pipe, I'm done.

Only one quick question left.... The idle screw. When I had it backed out, it was coughing along at 400 rpms or so and I had to put the screw in to slightly and sudenly hear a hissing sound and it then started to idle regularly. I thought there was supposed to be a small amount of air coming in even with the blades 100% closed....oh well

IT RUNS!!! WOOPEE!

Thanks to everyone for helping out!

Ex4bangerStang · 10-28-2004, 01:57 AM

Ok Heres the Thing...Dont Ever use RTV on any Head Surface...Including The Intake Port Runners.....The gaskets you buy should have a coating on em for when they are torqued down and warm up they seal great.....The end Gaskets I get are made of rubber and have lil saddle like tabs that hold them in place

10-21-2004, 07:26 PM	#2
crazypete Registered Member Join Date: Sep 2002 Location: Boston Posts: 592	Re: Carb has too much idle hole drilled? AHA! I did the intake test and I got a flickering 0-1 psi(?). There is one and only one vacuum stem and that had the guage on it (slid onto a hose with a clamp) so I guess it is the intake. It must be an intenal leak because I rtv'ed around the intake top earlier and rtv'ed the carb base so it was not leaking from there either. The carb was fully closed. As long as I will be pulling the intake, I'll heli-coil that annoying stripped thread. Well, at least I know I did the head/intake port correctly and the rockers were a good purchase. That low cylinder pressure still bugs me but well let the "seat of the pants" decide how this project turned out. __________________ 91 GT Carb conversion, holley 600 double pumper, edelbrock performer intake, FMS "C" drop springs, march 1000 underdrive pullies, crane 1.7 roller rockers, GT-40P headers, bassani x pipe, american thunder catback, FMS 4.56's, msd aL6, trunkmount battery, A/C eliminator kit, 3000 stall tci streetfighter, AOD with transgo kit, A+ servo, 300M hardened lockup shaft, kevlar bands and 28,000 gvw trans cooler, 3 core radiator, 300 lbs stripped with a full interior Last edited by crazypete; 10-22-2004 at 07:21 AM..

10-22-2004, 09:18 AM	#3
88fivepointoh Registered Member Join Date: Aug 2002 Location: Rochester Posts: 553	Re: Carb has too much idle hole drilled? OK, One question, The casing is aluminum, water will cause it to corrode quickly especially if boiled. I did this on my 87 Camaro once to clean it and destryed the Carb.. Was a great excuse for a new one however.. hehehe.. Also RTV, BAD!!! on carbs, clogs everything up. I am leary on putting expoxy on the Throttle Blades. it it falls down there and makes its way in the cylinder, you could cause danmages. weld them closed would be best and grind them down smooth...

10-22-2004, 10:14 AM	#4
crazypete Registered Member Join Date: Sep 2002 Location: Boston Posts: 592	Re: Carb has too much idle hole drilled? I'm not sure about the corrosion thing since the carb is aluminum after all BUT after cleaning step number 2, there was white powdery stuff on everything which could have been corroded aluminum. But, being a stubborn SOB, I refuse to write off the avenger since it was my first carb. I will boil and soak and do whatever necessary to clean her out. It was probably fine seeing how my intake probably has an internal leak. The bolt threads are loc-tited (is that epoxy? Sure doesnt look like it). In all honesty, the screws could hold themselves in without extra help but it seemed like quick and dirty insurance so I dont have little screw heads in the intake. I will de-rtv the carb when putting the intake back on. __________________ 91 GT Carb conversion, holley 600 double pumper, edelbrock performer intake, FMS "C" drop springs, march 1000 underdrive pullies, crane 1.7 roller rockers, GT-40P headers, bassani x pipe, american thunder catback, FMS 4.56's, msd aL6, trunkmount battery, A/C eliminator kit, 3000 stall tci streetfighter, AOD with transgo kit, A+ servo, 300M hardened lockup shaft, kevlar bands and 28,000 gvw trans cooler, 3 core radiator, 300 lbs stripped with a full interior

10-22-2004, 07:53 PM	#5
Rev Registered Member Join Date: Nov 1998 Location: Houston, Tx. Posts: 3,887	JB weld Pretty sure that JB Weld is gas proof. Soldering the holes closed would probably work well too and could be smoothed off pretty easily. Actual welding might warp the butterflies with the heat and that would cause all kinds of problems. Rev __________________ '66 Coupe, 306, 350-375 HP, C-4, 13.07 e.t., 104.8 mph, 1/4 mi. O.B.C. #2 '66 coupe Last edited by Rev; 10-22-2004 at 08:14 PM..

10-24-2004, 07:06 PM	#6
crazypete Registered Member Join Date: Sep 2002 Location: Boston Posts: 592	Re: Carb has too much idle hole drilled? Victory! Got it! It was the intake. I pulled it and got some good felpro gaskets and RTV'ed like crazy and torqued the intake down to specs.....then I saw that the stupid cork end gaskets had been ejected so I RTV'ed the ends shut and WHAM! It started up! What a difference. I was using 5-6 full turns of all four idle screws to try and get it to idle.... now, I am using 1.5 turns of each of the 2 fronts only and it idles like a charm! It can actually idle lean! The avenger never was able to idle less than med rich. That black smoke mentioned before was actually burning oil from the cylinders I fogged. I know cause there's a pool of grey burnt oil behind the car. I ran it for 30 mins to clear out the cylinders and the exhaust and apart from a header that refuses to accept it's pipe, I'm done. Only one quick question left.... The idle screw. When I had it backed out, it was coughing along at 400 rpms or so and I had to put the screw in to slightly and sudenly hear a hissing sound and it then started to idle regularly. I thought there was supposed to be a small amount of air coming in even with the blades 100% closed....oh well IT RUNS!!! WOOPEE! Thanks to everyone for helping out! __________________ 91 GT Carb conversion, holley 600 double pumper, edelbrock performer intake, FMS "C" drop springs, march 1000 underdrive pullies, crane 1.7 roller rockers, GT-40P headers, bassani x pipe, american thunder catback, FMS 4.56's, msd aL6, trunkmount battery, A/C eliminator kit, 3000 stall tci streetfighter, AOD with transgo kit, A+ servo, 300M hardened lockup shaft, kevlar bands and 28,000 gvw trans cooler, 3 core radiator, 300 lbs stripped with a full interior Last edited by crazypete; 10-25-2004 at 07:27 AM..

10-28-2004, 01:57 AM	#7
Ex4bangerStang Registered Member Join Date: Oct 2004 Posts: 2	Re: Carb has too much idle hole drilled? Ok Heres the Thing...Dont Ever use RTV on any Head Surface...Including The Intake Port Runners.....The gaskets you buy should have a coating on em for when they are torqued down and warm up they seal great.....The end Gaskets I get are made of rubber and have lil saddle like tabs that hold them in place

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