The ignition or powertrain control module (PCM) usually controls When a Crankshaft – Camshaft Position Sensor goes BAD, your vehicle will not start. I Think the Mechanical Fuel Pump Is the Culprit! I agree with Bill. I took it apart, cleaned it, & swapped the red pumps spring into it- it holds steady 5.5psi and no leaking. It seemed ok for a while but now it leaking … Fuel should not come out of here and it means that your fuel pump diaphragm [inside the pump] has developed a small hole and is beginning to leak fuel and should be replaced. When the diaphragm goes up air comes out of that hole when it goes back down air rushes back in. My fuel pump is leaking from the Vent hole. Its leaking from the area where the electric motor bolts to the pump body. Fuel leaking out of the two vent holes at the top of the casting. Page 1 of 2 - Fuel Pump Leak - posted in Problems, Questions and Technical: Hi I have just got our 1988 Mini City back on the road after being laid up for a few years. There's usually not much pressure behind the pump and if the diaphragm is ruptured, the oil will be diluted....at least that has been the case whenever I ran across ruptured diaphragms. Most mechanical fuel pumps have a weep hole on the bottom side of the unit. my 79 truck came with an electric fuel pump and the head had no place to mount a mechanical pump or power steering pump. New Water Pump Leaking From Weep Hole - Chevy And Gmc Duramax Diesel Forum. Re: holley blue pump is leaking- update & fixed *update- the internal regulator apparently wasn't allowing the pressure to bypass back to the low pressure side & that little hole must be a weep hole for fuel going to the fuel pump motor. This prevents fuel from leaking into the builge which in a boat could be instant deaster. GrapeApe, Aug 4, 2015. It has only 154 miles on it right now, but at about 100 miles it mysteriously had an oil leak. This leak may be anything from a few drops to a steady stream of fuel. The oil that leaks out that way is getting slung up from the cam eccentric or the timing chain. The car was just sitting and I started smell fuel and I went out to the garage and found fuel poring out of the hole. Many inexpensive When the internal diaphragm leaks, fuel escapes through the weep hole to notify the vehicle owner of a malfunction. Sometimes that still happens and you full the crankcase with diesel. Fuel may leak from the weep hole which is located on the bottom of the Stanadyne Model DB4 Fuel Injection Pump, near the pump mounting flange. fuel pump was leaking oil from weephole,replaced with new pump and it's leaking too,can anyone tell me why this is happening?i've changed oil filter,pulled pump apart diaphragm was good & cleaned pcv port to carbany ideas? has anyone ever herd of this? Does the pump have a 2nd smaller nipple for a smaller rubber fuel line like this. OIL LEAK SOUNDS LIKE TO ME EITHER THE FUEL PUMP DIAPHRAM TORE,or oherwise let go.The hole you are refering to (if i'm reading this correctly)is called a "weep hole".Just like the one on your water pump.It's there to signify an internal pump malfunction .I woulld check to make sure you don't have gasoline mixed in that oil you are leaking,check your dip stick,smell it, don't … A mechanical OEM style pump can pump fuel into the crank case or externaly some cases both. I took everything apart assuming there would be a gasket or seal between the pump body and the motor but there isnt one. Yesterday I noticed that it was leaking fuel. I’m guessing the leak is coming from the weep hole on the pump. Reinstall the spacer plate, use a new gasket. There is what looks to be a weep hole right in this area where the lock nut for one of the bolts is. I'm no professional so I had the dealer do it. They can be re-inserted with the washers under the head thereby preventing contact with the rod but sealing the hole. I just had the same problem with my roadster. That ruins the engine in short order too. I figured it needed a new gasket and o-ring and I would replace them before I put the carbs back on. I am getting the same problem. I am just curious if I could get away with just replacing the front lip seals of the mechanical fuel pump … With the gasket on the fuel pump insert the fuel pump arm into the hole … Disassembled the pump and the diaphragm was cracked forcing fuel to the upper cavity. That is not a weep hole, it is a vent to allow the diaphragm to function properly. The pump was replaced by the PO about 4000k miles ago. If this is a mechanical pump located on the side of the engine then what you are most likely seeing is fuel dripping out from the weep hole in the pump. But, after seeing the weep hole/vent on top of the fuel pump spit oil I confirmed it. My fuel pump is leaking from the Vent hole. Had it replaced with a Napa water pump which started leaking a few thousand miles later from the weep hole. Generally the unit will come in with a complaint of a fuel leak at the fuel pump. and i guess some of the 1980's must have too. I replaced the mechanical seal behind the water pump and it still leaked. This weep hole often resides between seals that separate the oil side from the coolant side. This is the second time this year. I am on the third one in months leaking out the upper body weep hole, The first one was a blue about 4 years old, replaced the gasket, still leaked, replaced the housing ,less leak but out the weep hole, Got a new summitt pump and it lasted about 7 weeks and its leaking out the weep hole too. A mechanical OEM style pump can pump fuel into the crank case or externaly some cases both. ... Water pumps can sometimes support a mechanical fan. On V8 engines, a push rod between the camshaft eccentric and the fuel pump operates the fuel pump arm.So, There are two holes in the passenger side front of the engine. ... they get brittle and are not expensive. Many times the leak is just the rubber hose. The fuel pump is leaking oil out of a threaded port; between pump and motor. The leak is normally observed on a cold engine and is aggravated by cold weather. Coolant level is fine. Once the (2) fuel pump mount The pump has about 30k miles on it. (I am getting oil out of the weep holes on the fuel pump), pvc is working no smell of gas on the dipstick. Leaking fuel from pump.seems to be a little hole on under side of pump just below the pressed metal join. An engine that misfires, runs lean, hesitates, or stalls could have a leaking diaphragm or valve within the fuel pump. This is NOT a defect in the pump and further diagnostics need to be performed to find the root cause. If you were in there recently for the hoses double check and make sure you do not have anything loose and leaking. It does not happen all the time but when it does it looks like fuel is being pumped out from beneath the pump its self. The mechanical fuel pump on my 240Z is leaking oil from a small vent hole in the side of the pump body near where the pivot pin is. I have allot of oil coming out of the weep hole under the water pump. If a mechanical pump leaks fuel at the weep hole it is defective or damaged and nothing done external to the pump will correct the problem. Re: Please Help - 20R Mechanical Fuel Pump Leaking Oil « Reply #7 on: Mar 11, 2008, 08:58:49 AM » the 79 came with an electric fuel pump in the tank stock. Most mechanical fuel pumps have a weep hole on the bottom side of the unit. There are marine style mechanical pumps that have a tube on the weep hole that a hose is attached to and it is routed into the carb which is also a marine unit. FASS Tech 101 (Leaking Fitting) The FASS tech department receives calls everyday with questions that range from … Titanium Series How A FASS Works. The weep holes on a fuel pump should leak fuel at worst. This prevents fuel from leaking into the builge which in a boat could be instant deaster. * A coolant leak coming from the weep hole is a sign of water pump bearing or seal failure. I rebuilt the turbo and fuel bowl last summer and replaced all the washers and sleeves for the fuel so I should be good to go. I removed the fuel pump and both gaskets and the spacer are there so the pump looks fine. Every now and again petrol is leaking from around the fuel pump while the engine is running. The car was just sitting and I started smell fuel and I went out to the garage and found fuel poring out of the hole. New pump would be $8000 plus. The pivot pin was sealed with silicone by the previous owner (a common remedy), but the vent hole is leaking oil into the prop-wash of the cooling fan and spraying the plug-side of the engine bay. M. mechanic mark Lawn Pro. Most of the time when a pump fails it leaks fuel out a weep hole so it wont flow into the engine but. Your diaphragm is broken and it will not pump fuel with a broken diaphragm. On top of oil in the fuel and fuel in the oil, oil from the pump weep hole usually ends up on the ECM and over time softens the wiring harness seals that leads to headaches down the road. There is the weep hole that will leak if the pump is bad and the large bolt on the back is the banjo bolt which has the fuel going through it to the back of the heads. Watch this short but great visual representation of how a FASS Titanium … How A FASS Can Help Your Duramax Diesel. I didn't know anything about a weep hole or mechanical seal or anything at that time. If this is a mechanical pump located on the side of the engine then what you are most likely seeing is fuel dripping out from the weep hole in the pump. Not many pumps have these holes. Pressure Fuel Pump Weep Hole for Heavy Duty DD Engines Summary: Occasionally we see trucks come in with fuel leaking from the high pressure fuel pump weep hole. Both of these problems cause the fuel pressure to drop, starving the carburetor of gasoline and creating the above symptoms. Okay, thank you for the clarification, If the only thing that is leaking is the fuel pump from the weep hole then there really is nothing else that will need to be replaced. Had an old AC mechanical pump, #40083, that was used at least 10 years ago. I was pretty confused as that is a fuel line, not oil. The phone calls are prompted by the website and not by me, we can do this with out a call. Oil shouldn't leak out of your mechanical fuel pump weep hole because you're not feeding any pressurized oil into it. 01-04.5 LB7 Duramax Powertrain > new water pump leaking from weep hole So my original water pump went at 126k. My Holley mech pump took a dump about a month ago, thought I had a line leaking, come to find out there was something like a weep hole built into the body of the pump, with the motor started it would pump gas out that little hole, still don't know why the hole is even there, but had to replace it for the time being with a factory replacement type for now. Reinstall the spacer plate, use a new gasket. Fill pump reservoir with fluid. When my fuel pump went bad, it started leaking fuel into the oil pan. I searched everywhere until I finally isolated the leak to the fuel pump or in-line fuel filter. ANyone here running a HOlley Electric fuel pump? Most fuel pumps have a weep hole that will leak oil if the internal diaphragm ruptures, this could also dilute the oil with fuel. First symptom was diesel in engine oil and eventually constant fuel leaking out of weep hole. So I proceeded to remove the carbs and came inside and googled "cx500 water pump gasket". AutoZone.com Spectra Premium Fuel Pump A1001MP - Read Reviews on Spectra Premium #A1001MP I have a 1968 AMC AMX 290 automatic w/electric wiper motor. When the internal diaphragm leaks, fuel escapes through the weep hole to notify the vehicle owner of a malfunction. I got here a leaking mechanical fuel pump on a 3304 PC engine. What benefits can you get by adding a FASS Titanium Series diesel fuel pump … Joined Jul 15, 2013 Threads 155 Messages I have replaced 2 fuel pumps. Defect in the pump have a 1968 AMC AMX 290 automatic w/electric wiper motor came inside googled! 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