Posted by Deane
I still have to change the shiny spring clamps on my brake and clutch reservoir lines to the deemed-correct black oxide finish. And might as well flush the fluid while I'm there. Looks like no golf this weekend.
Fuel Starvation
Re: Fuel Starvation
Posted by John Vardanian
Tom,
I feel a lot better now that I figured out the problem. The engine was running on 9 cylinders as one of the points was not working. It is amazing to me that an engine can run so well on just 3/4 of its capacity! A testamony to the might of the V12!
I plan to take the Coastal Highway 1 from SF to Monterey.
Looking forward to meeting you.
john
Tom,
I feel a lot better now that I figured out the problem. The engine was running on 9 cylinders as one of the points was not working. It is amazing to me that an engine can run so well on just 3/4 of its capacity! A testamony to the might of the V12!
I plan to take the Coastal Highway 1 from SF to Monterey.
Looking forward to meeting you.
john
Re: Fuel Starvation
Posted by Tom
Hi John,
When you've got 12 cylinders firing to turn a crankshft, it's no wonder you don't notice a missing cylinder! Lose one cylinder on a 4 cylinder engine, and you'll notice!
Three years ago I drove up that road after the Pebble beach event, and I wished I had a different car than my rental car to drive! Maybe next time, I'll fly out to SF and can join you for the ride down!
I'll see you Friday!
Tom  
Hi John,
When you've got 12 cylinders firing to turn a crankshft, it's no wonder you don't notice a missing cylinder! Lose one cylinder on a 4 cylinder engine, and you'll notice!
Three years ago I drove up that road after the Pebble beach event, and I wished I had a different car than my rental car to drive! Maybe next time, I'll fly out to SF and can join you for the ride down!
I'll see you Friday!
Tom  
Re: Fuel Starvation
Posted by John Vardanian
Highway 1 is a great ride but when you arrive there is a good bit of ocean spray on the car.
Sorry, Tom. I would offer you a ride this time but the seat will be occupied by Mrs. Vardanian.
I dread having to fill up the back of the car with the weekend's necessities. Those big 205/70 series tires rub againt the wheel well on every dip. If I didn't have so many other, more essential things to get for the car I would get some proper tires. Speaking of things to get, is there a cheaper way out in replacing distributor caps. Last I heard they were about $250 a piece. The electrodes in mine are pretty pitted.
john
Highway 1 is a great ride but when you arrive there is a good bit of ocean spray on the car.
Sorry, Tom. I would offer you a ride this time but the seat will be occupied by Mrs. Vardanian.
I dread having to fill up the back of the car with the weekend's necessities. Those big 205/70 series tires rub againt the wheel well on every dip. If I didn't have so many other, more essential things to get for the car I would get some proper tires. Speaking of things to get, is there a cheaper way out in replacing distributor caps. Last I heard they were about $250 a piece. The electrodes in mine are pretty pitted.
john
Re: Fuel Starvation
Posted by Tom
Hi John,
See, there is an advantage to a 2+2!...Although I'd trade my 330 America for a Lusso any day! (don't tell my car I said that!)
Sorry, there's no way out of that one! Distibutor caps are $$$! They last quite a while once you ante up the dough!
Tom
Hi John,
See, there is an advantage to a 2+2!...Although I'd trade my 330 America for a Lusso any day! (don't tell my car I said that!)
Sorry, there's no way out of that one! Distibutor caps are $$$! They last quite a while once you ante up the dough!
Tom
Re: Fuel Starvation
Posted by Bruce Snowdon
Dear John:
I was interested to read about your mechanical fuel pump problems as I have been experiencing the same problems myself with my 330 GTC. When I first began to experience fuel starvation problems I went through the entire fuel system. I replaced the fuel pick-up (cracked), the yellow fuel lines, replaced the filters etc. etc but the problem persisted. I noticed (particularly when the engine was warm) that the glass fuel bowl on the inner fender was only 1/4 full or less at these times. I rebuilt the mechanical fuel pump with a kit. I assumed that this would be correct for my pump but the diaphragm was black neoprene instead of the original red rubberized fabric and the replacement valves did not at all match the originals. When I disassembled the pump I also found a broken linkage between the lever arm and the diaphragm which I replaced. This was despite having the correct spacer in place between the pump and the block. I used the new diaphragm but unfortunately the fuel starvation problem persisted.
I wasn't happy with this new diaphragm so I replaced the original without effect. The car ran well with the electric pump turned on but I felt that the mechanical pump should be more effective. My fuel rail has openings at the front and rear for attachments to the yellow hoses from the two fuel pumps and a third smaller diameter branch at the rear which feeds back into the fuel filler pipe. I attached a fuel pressure gauge to this third opening for pressure readings. I found that the electric pump alone would give a fuel pressure of 2.5 PSI. With both pumps running the pressure was 3 PSI. I ordered another pump rebuild kit (original Fispa this time) from another source. This contained the correct diaphragm and valves. I installed it and now the fuel pressure measured 5 PSI with the mechanical pump only running. In addition, the glass fuel bowl was full with the engine running. My success was short lived however as the problem with low fuel pressure has recurred, again particularly when the engine is hot. Your solution of thinning the spacer between the pump and case to increase diaphragm movement is clever but at one point these pumps were designed to work with this spacer and I can't figure out how!
I have two questions, 1; are there any professionals out there who can explain these pump problems? or 2; is there a shop that can bench test/flow these pumps to correctly refurbish them? I'd appreciate any feedbak to this problem.
Dear John:
I was interested to read about your mechanical fuel pump problems as I have been experiencing the same problems myself with my 330 GTC. When I first began to experience fuel starvation problems I went through the entire fuel system. I replaced the fuel pick-up (cracked), the yellow fuel lines, replaced the filters etc. etc but the problem persisted. I noticed (particularly when the engine was warm) that the glass fuel bowl on the inner fender was only 1/4 full or less at these times. I rebuilt the mechanical fuel pump with a kit. I assumed that this would be correct for my pump but the diaphragm was black neoprene instead of the original red rubberized fabric and the replacement valves did not at all match the originals. When I disassembled the pump I also found a broken linkage between the lever arm and the diaphragm which I replaced. This was despite having the correct spacer in place between the pump and the block. I used the new diaphragm but unfortunately the fuel starvation problem persisted.
I wasn't happy with this new diaphragm so I replaced the original without effect. The car ran well with the electric pump turned on but I felt that the mechanical pump should be more effective. My fuel rail has openings at the front and rear for attachments to the yellow hoses from the two fuel pumps and a third smaller diameter branch at the rear which feeds back into the fuel filler pipe. I attached a fuel pressure gauge to this third opening for pressure readings. I found that the electric pump alone would give a fuel pressure of 2.5 PSI. With both pumps running the pressure was 3 PSI. I ordered another pump rebuild kit (original Fispa this time) from another source. This contained the correct diaphragm and valves. I installed it and now the fuel pressure measured 5 PSI with the mechanical pump only running. In addition, the glass fuel bowl was full with the engine running. My success was short lived however as the problem with low fuel pressure has recurred, again particularly when the engine is hot. Your solution of thinning the spacer between the pump and case to increase diaphragm movement is clever but at one point these pumps were designed to work with this spacer and I can't figure out how!
I have two questions, 1; are there any professionals out there who can explain these pump problems? or 2; is there a shop that can bench test/flow these pumps to correctly refurbish them? I'd appreciate any feedbak to this problem.
Re: Fuel Starvation
Posted by John Vardanian
Bruce,
Here's my experience with the fuel starvation.
I bought the car in April of 2000---my first Ferrari. When I paid the seller and got in it to drive home, he pointed out to the electric pump switch and told me "this is the electric pump switch. I leave it on all the time" I said okay and drove the car home then a few weeks later I decided that the electric pump didn't need to be on all the time so I turned it off. That is when I discovered the problem.
The symptoms were: under cruising acceleration the engine would back fire through the carbs giving this sneezing sound from under the hood, and during extended idle the engine would stall. On inspection of the glass filter bowl I noticed it was less than half full. Revving the engine would not fill up the bowl.
This is what I did:
1) Overhauled the mechanical pump with a new (black diaphram) kit. Problem didn't go away.
2) Overhauled the filter/regulator with a new kit. Problem didn't go away.
3) Inspected the filter element at the electric pump. It was new.
4) Removed the flex line running from the filter/regulator to the carb fuel manifold and put a gauge at the end while the engine ran with the electric pump. Read about 4 psi. Removed the gauge and ran the engine again allowing gas to pour out of the hose and noticed that fuel was flowing out at very low rate.
5) Removed the insulator block (spacer) that is between the pump and the engine block and reinstalled the pump. Gas flowed out of the open end of the hose at a much greater rate (at a throw out of about 2-3 inches). Buttoned everything back up and drove the car. No more sneezing, no more stalling. Glass bowl stayed full. Problem went away.
6) A month later, while on the road, the car stalled. No fuel was getting to the engine. Drove the car home on the electric pump. Opened up the mechanical pump and noticed that one of the flat metal tabs (linkages) that connect to the shaft of the diaphram was broken. The other was on the verge of breaking.
7) Replaced the broken tabs, but put the new ones back in the reverse orientation, i.e., upside down. Put the insulator block back in place. Buttoned up the car and took it for a drive. The problem went away.
Now the only problem I have is an occasional sneezing under acceleration. I tend to think that this may be a carburetion problem. Could it be that the last person who overhauled the pump put those levers back in backwards? Maybe. I keep a diary of the work I do on the car. If you need to know which way the tabs went in let me know.
I would be very interested in learning from your problem. Please keep me posted. Thanks.
John Vardanian
Bruce,
Here's my experience with the fuel starvation.
I bought the car in April of 2000---my first Ferrari. When I paid the seller and got in it to drive home, he pointed out to the electric pump switch and told me "this is the electric pump switch. I leave it on all the time" I said okay and drove the car home then a few weeks later I decided that the electric pump didn't need to be on all the time so I turned it off. That is when I discovered the problem.
The symptoms were: under cruising acceleration the engine would back fire through the carbs giving this sneezing sound from under the hood, and during extended idle the engine would stall. On inspection of the glass filter bowl I noticed it was less than half full. Revving the engine would not fill up the bowl.
This is what I did:
1) Overhauled the mechanical pump with a new (black diaphram) kit. Problem didn't go away.
2) Overhauled the filter/regulator with a new kit. Problem didn't go away.
3) Inspected the filter element at the electric pump. It was new.
4) Removed the flex line running from the filter/regulator to the carb fuel manifold and put a gauge at the end while the engine ran with the electric pump. Read about 4 psi. Removed the gauge and ran the engine again allowing gas to pour out of the hose and noticed that fuel was flowing out at very low rate.
5) Removed the insulator block (spacer) that is between the pump and the engine block and reinstalled the pump. Gas flowed out of the open end of the hose at a much greater rate (at a throw out of about 2-3 inches). Buttoned everything back up and drove the car. No more sneezing, no more stalling. Glass bowl stayed full. Problem went away.
6) A month later, while on the road, the car stalled. No fuel was getting to the engine. Drove the car home on the electric pump. Opened up the mechanical pump and noticed that one of the flat metal tabs (linkages) that connect to the shaft of the diaphram was broken. The other was on the verge of breaking.
7) Replaced the broken tabs, but put the new ones back in the reverse orientation, i.e., upside down. Put the insulator block back in place. Buttoned up the car and took it for a drive. The problem went away.
Now the only problem I have is an occasional sneezing under acceleration. I tend to think that this may be a carburetion problem. Could it be that the last person who overhauled the pump put those levers back in backwards? Maybe. I keep a diary of the work I do on the car. If you need to know which way the tabs went in let me know.I would be very interested in learning from your problem. Please keep me posted. Thanks.
John Vardanian
Re: Fuel Starvation
Posted by John Vardanian
Bruce,
I forgot to answer your other questions. Sorry.
When I was having the fuel problem I called Patrick Ottis (a noted Ferrari mechanic in Northern California). He said the way they tackle the problem is by milling the bakalite insulator/spacer.
You were also asking about refurbished pumps. Dennis McCann in Ohio has these Fispa pumps, both rebuilt and brand new.
Bruce,
I forgot to answer your other questions. Sorry.
When I was having the fuel problem I called Patrick Ottis (a noted Ferrari mechanic in Northern California). He said the way they tackle the problem is by milling the bakalite insulator/spacer.
You were also asking about refurbished pumps. Dennis McCann in Ohio has these Fispa pumps, both rebuilt and brand new.
Re: Fuel Starvation
Posted by Tom
Hi Bruce,
Have you fuel tanks been cleaned? Sometimes the electric fuel pump can help overcome a clogging, but the mechanical pump may not pull enough fuel to run the engine.
What part of the country are you located?
Tom Yang
Hi Bruce,
Have you fuel tanks been cleaned? Sometimes the electric fuel pump can help overcome a clogging, but the mechanical pump may not pull enough fuel to run the engine.
What part of the country are you located?
Tom Yang
Re: Fuel Starvation
Posted by Bruce Snowdon
Tom and John:
Thanks for your response. I am located in Ontario across the river from Detroit. I have checked the fuel tanks and they are clean. I am convinced that this problem is with the mechanical pump but I have yet to find the solution. I may make a thinner spacer to increase pump throw but I don't want to end up breaking the linkage arms.
Incidentally, from reading your web site, I don't think that you have run your engine yet. When you do I will be interested to hear if you have any problems with leakage from the yellow fuel lines at the connectors. I used a variety of Loctite products to seal the fittings into the hoses but there is still a tiny amount of oily residue that collects on the underside of the hoses. Did you use any particular sealant with your hoses and fittings?
Bruce
Tom and John:
Thanks for your response. I am located in Ontario across the river from Detroit. I have checked the fuel tanks and they are clean. I am convinced that this problem is with the mechanical pump but I have yet to find the solution. I may make a thinner spacer to increase pump throw but I don't want to end up breaking the linkage arms.
Incidentally, from reading your web site, I don't think that you have run your engine yet. When you do I will be interested to hear if you have any problems with leakage from the yellow fuel lines at the connectors. I used a variety of Loctite products to seal the fittings into the hoses but there is still a tiny amount of oily residue that collects on the underside of the hoses. Did you use any particular sealant with your hoses and fittings?
Bruce
Re: Fuel Starvation
Posted by Tom
Hi Bruce,
Is this oily residue collecting on the seam of the yellow hose? Trying to save some money (this stuff is sold by the inch!), I'm reusing some good hose Francois has saved from previous restorations. I've noticed that there was a different type of hose in the batch that he gave me. This yellow hose had what first looked like oily residue, but on cleaning it off I realized it was coming out from inside the hose via the seam of the outer covering. Perhaps the rubber inside was reacting to the gasoline that was passed through it.
I used a cement to seal the hose to the fittings, and will soon see if I used the right stuff. If there are no leaks, I will promise to reveal what I used!
Tom  
Hi Bruce,
Is this oily residue collecting on the seam of the yellow hose? Trying to save some money (this stuff is sold by the inch!), I'm reusing some good hose Francois has saved from previous restorations. I've noticed that there was a different type of hose in the batch that he gave me. This yellow hose had what first looked like oily residue, but on cleaning it off I realized it was coming out from inside the hose via the seam of the outer covering. Perhaps the rubber inside was reacting to the gasoline that was passed through it.
I used a cement to seal the hose to the fittings, and will soon see if I used the right stuff. If there are no leaks, I will promise to reveal what I used!
Tom  
Re: Fuel Starvation
Posted by Mike Dunn
Hate to tell you this guys but the stock fuel pump stroke is more than adequate to feed a puny little 250 engine, the same pump handles the 5liter engine in my 500SF. Either the pump is bad or there is a restriction in the system. The smallest leak on the suction side will cause this problem yet may not visibly leak fuel. I would start with a vacuum test on the pump and then next pull the pickup line out of the tank. It's probably got a plugged screen either from varnish or tank rust residue or more likely both.
See all my stuff at www.madenterprise.com.
Hate to tell you this guys but the stock fuel pump stroke is more than adequate to feed a puny little 250 engine, the same pump handles the 5liter engine in my 500SF. Either the pump is bad or there is a restriction in the system. The smallest leak on the suction side will cause this problem yet may not visibly leak fuel. I would start with a vacuum test on the pump and then next pull the pickup line out of the tank. It's probably got a plugged screen either from varnish or tank rust residue or more likely both.
See all my stuff at www.madenterprise.com.
Re: Fuel Starvation
Posted by Neil Albaugh
My 250GTE had exactly the same vapor lock problems from time to time. My symptoms were the same as yours; my solution to the problem was the same as FAF's mechanic's-- whack the electric fuel pump 'til it went tic- tic- tic again. Eventually, removing the electric fuel pump and cleaning it out thoroughly solved the intermittent solenoid plunger's sticking problem.
Regards, Neil
My 250GTE had exactly the same vapor lock problems from time to time. My symptoms were the same as yours; my solution to the problem was the same as FAF's mechanic's-- whack the electric fuel pump 'til it went tic- tic- tic again. Eventually, removing the electric fuel pump and cleaning it out thoroughly solved the intermittent solenoid plunger's sticking problem.
Regards, Neil