Fuel in intake

GallopinGhost · 05-30-2019, 01:43 PM

Has anyone seen this ? I have a 383 mopar stock engine and have been getting fuel fouled spark plugs and I see fuel on the plenum floor of the intake. It's dual plane intake, fuel is on both sides. I've been working on the carb (holley) thinking too much of the transfer slot is exposed. The heat passage is blocked, so I'm wondering is the fuel puddling up because I've blocked the heat passage which not letting the fuel atomize ? I thought I had fuel in the oil,but I had it analyzed and they didn't detect anything. I was thinking about putting hotter plugs in it and maybe that would burn the fuel off. any experience ??

FED 387 · 05-30-2019, 01:59 PM

Overly rich or weak-marginal ignition system ---is it every plug or just one?

GallopinGhost · 05-30-2019, 02:10 PM

Ignition should be good. Everything new, msd dist., daytona sensors box. I've checked wire resistance from inside of cap to plug, all good.

it's 6 out of 8 plugs, I'm thinking cyl. to cyl distribution of this intake is pretty bad. Once I get to fine tuning it, pretty sure it will have staggered jetting.

don't think its rich basically. fuel mixture screws are adjusted to rpm/manifold vacuum

Larry Hill · 05-31-2019, 07:38 AM

Pull carb off and keep the fuel line hooked up. Then hold it level and have someone turn on fuel pump and see where the fuel is leaking. It maybe a gasket that is allowing fuel to drain through a vacuum port into the intake.

GallopinGhost · 05-31-2019, 08:58 AM

I've tried that Larry, not a drop. fuel pressure at 6#. When the engine is running, I can look down and nothing is coming out of the boosters. But when I take the carb off, the top of the base gasket is always wet. It's a 4 hole gasket to match intake. I'm missing something..

FED 387 · 05-31-2019, 10:48 AM

What kind of accelerator pump do you have-did u check the vacuum plug too--try another carb see if it still persists

Alan Nyhus · 05-31-2019, 12:05 PM

What's your power valve situation?

FED 387 · 05-31-2019, 12:38 PM

I meant power valve not vacuum plug

GallopinGhost · 05-31-2019, 01:40 PM

I don't have another good carb to try. Accelerator pump is 30cc, PV is 2.5. This problem happens after just idling. I have a plug for the PV, yet to try it though. I guess I'll try to map out all the passages next. Also will post some pics.

NORMAN BARNARD · 05-31-2019, 01:52 PM

What is the list number of the holley carb.???

05-30-2019, 01:43 PM	#1
GallopinGhost Member Join Date: Jun 2010 Location: VA Posts: 228 Likes: 23 Liked 21 Times in 13 Posts	Fuel in intake Has anyone seen this ? I have a 383 mopar stock engine and have been getting fuel fouled spark plugs and I see fuel on the plenum floor of the intake. It's dual plane intake, fuel is on both sides. I've been working on the carb (holley) thinking too much of the transfer slot is exposed. The heat passage is blocked, so I'm wondering is the fuel puddling up because I've blocked the heat passage which not letting the fuel atomize ? I thought I had fuel in the oil,but I had it analyzed and they didn't detect anything. I was thinking about putting hotter plugs in it and maybe that would burn the fuel off. any experience ?? __________________ Brian Carpenter Stock 1358

05-30-2019, 01:59 PM	#2
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,349 Likes: 325 Liked 280 Times in 150 Posts	Re: Fuel in intake Overly rich or weak-marginal ignition system ---is it every plug or just one?

05-30-2019, 02:10 PM	#3
GallopinGhost Member Join Date: Jun 2010 Location: VA Posts: 228 Likes: 23 Liked 21 Times in 13 Posts	Re: Fuel in intake Ignition should be good. Everything new, msd dist., daytona sensors box. I've checked wire resistance from inside of cap to plug, all good. it's 6 out of 8 plugs, I'm thinking cyl. to cyl distribution of this intake is pretty bad. Once I get to fine tuning it, pretty sure it will have staggered jetting. don't think its rich basically. fuel mixture screws are adjusted to rpm/manifold vacuum __________________ Brian Carpenter Stock 1358 Last edited by GallopinGhost; 05-30-2019 at 02:12 PM.

05-31-2019, 07:38 AM	#4
Larry Hill Live Reporter Join Date: Oct 2004 Location: Hickory, Ky Posts: 10,276 Likes: 1,635 Liked 9,449 Times in 1,954 Posts	Re: Fuel in intake Pull carb off and keep the fuel line hooked up. Then hold it level and have someone turn on fuel pump and see where the fuel is leaking. It maybe a gasket that is allowing fuel to drain through a vacuum port into the intake. __________________ IHM Used Parts https://ihmusedparts.com 888-821-1817

05-31-2019, 08:58 AM	#5
GallopinGhost Member Join Date: Jun 2010 Location: VA Posts: 228 Likes: 23 Liked 21 Times in 13 Posts	Re: Fuel in intake I've tried that Larry, not a drop. fuel pressure at 6#. When the engine is running, I can look down and nothing is coming out of the boosters. But when I take the carb off, the top of the base gasket is always wet. It's a 4 hole gasket to match intake. I'm missing something.. __________________ Brian Carpenter Stock 1358

05-31-2019, 10:48 AM	#6
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,349 Likes: 325 Liked 280 Times in 150 Posts	Re: Fuel in intake What kind of accelerator pump do you have-did u check the vacuum plug too--try another carb see if it still persists

05-31-2019, 12:05 PM	#7
Alan Nyhus VIP Member Join Date: Dec 2002 Location: Lower Dakota territory Posts: 1,164 Likes: 1,013 Liked 761 Times in 225 Posts	Re: Fuel in intake What's your power valve situation? __________________ "That'll never work....."

05-31-2019, 12:38 PM	#8
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,349 Likes: 325 Liked 280 Times in 150 Posts	Re: Fuel in intake I meant power valve not vacuum plug

05-31-2019, 01:40 PM	#9
GallopinGhost Member Join Date: Jun 2010 Location: VA Posts: 228 Likes: 23 Liked 21 Times in 13 Posts	Re: Fuel in intake I don't have another good carb to try. Accelerator pump is 30cc, PV is 2.5. This problem happens after just idling. I have a plug for the PV, yet to try it though. I guess I'll try to map out all the passages next. Also will post some pics. Attached Thumbnails __________________ Brian Carpenter Stock 1358 Last edited by GallopinGhost; 05-31-2019 at 01:50 PM.

05-31-2019, 01:52 PM	#10
NORMAN BARNARD Member Join Date: Mar 2006 Location: EL PASO, TEXAS Posts: 156 Likes: 0 Liked 2 Times in 2 Posts	Re: Fuel in intake What is the list number of the holley carb.???