Fuel pump push rod ?

[hawkeyesheroes]

HELP---I removed the delcotron adapter from my engine (69 Monza 110 ) , left the oil fill tube , oil filter and fuel pump all on the adaptor, ( I had removed the belt idler pulley ) , had trouble pulling the adapter off , trying to be careful not to tear the gasket , suddenly it lurched free and I'm sure I heard a little " clink " . I can't see that anything could have come off the bottom of the adaptor , but something appears to be missing to operate the fuel pump. the rod of the fuel pump cant possibly be long enough to be actuated by anything on the crankshaft . Is there some kind of a push rod from a crankshaft lobe that pushes the fuel pump rod up and down ? Could it have come out and fallen into the block and into the oil pan when I pulled the delcotron adapter off ? The car ran before I did all this , I only wanted to clean up this assembly and paint it . What did I get myself into ? Can anyone help ?
.

[terribleted]

Fuel pump pushrod is about 3/8 diameter, 5" long and has a spring on the top of it. It pushes into the hole in the adapter under the fuel pump and also into a guide hole in the rear housing under the adapter. There is no way it can fall out into the engine (on the floor perhaps). Usually the adapter is installed then the fuel pump push rod inserted and then the pump installed.

[bbodie52]

You normally should have pulled the push rod out before removing the oil filter adapter (see Fig. 60 below). If it fell out when you pulled the adapter, try looking in the tray under the crankshaft pulley... a lot of things tend to fall in there!

The paper gasket often is not reusable. You will probably need a new one with your next order from Clark's. http://www.corvair.com/user-cgi/catalog ... AIN&page=7



When you reinstall the fuel pump, be sure that you have installed it properly. I would confirm that the fuel pump is correctly seated and installed. There is a hole in the side of the pump shaft that the tapered bolt tip must seat into. If the pump is sitting too high and the bolt is simply pressing against the side of the pump housing, rather than seating inside the tapered hole, the pump push rod will not be doing its job. So first confirm proper pump installation, and then check the fuel pump output pressure and volume, as shown in the shop manual pages above. Fig. 57 in the shop manual page shows the tapered hole that the tip of the bolt fits into. This ensures proper installation and seating of the pump.

[/quote]

If you replace the fuel pump, be sure to check the output pressure of the new pump. The spring determines the output fuel pressure, and new production pumps sometimes produce to much fuel pressure. The Carter YH carburetor is particularly sensitive to excessive fuel pressure. If you find that the pressure exceeds the standards outlined in the shop manual, you might be able to solve the problem by swapping the spring from the old pump.

http://www.corvair.com/user-cgi/catalog ... IN&page=65

[Iceland Spyder]

He could have an electrik fuel pump if the rod is missing and the car was running before pump removal.

[hawkeyesheroes]

Thank you terrible ted, brad bodie, and Iceland spyder , I really appreciate your response. I had read the same pages in the corvair shop manual describing fuel pump parts , but still find it hard to believe that I cant find a 5 inch rod and spring that was somehow attached to it. I can find nothing under the crankshaft pulley or in the creases beside it. The only place I can think this stuff can be is in the oil pan . Guess I'll take off the pan and see what I can find. Thanks again.

[bbodie52]

I cannot see any way an object could get past the crankcase or rear housing castings and reach the oil pan. Only liquid reaches that area. It might have fallen into the cooling fan and could be sitting on the cylinder barrels or somehere else inside the sheet metal shrouds.

[terribleted]

It is physically impossible for the fuel pump push rod to fall thru into the oil pan. It has a larger part on the top that the spring pushes on to and the rod itself sits in a hole in the rear housing that is essentially the same diameter as the rod itself (housing hole acts like a bushing).

Is there an electric fuel pump installed in the car? If there is someone may have removed the fuel pump rod. Signs would be perhaps a rattling or whirring sound when the ignition is turned on but engine is not running. Such a pump could be located anywhere between the tank and the engine but should ideally by near the tank. Car would not run without a fuel pump and since you can not find a push rod either the car was not running before you removed the oil filter adapter or there is another source of fuel pressure, or you managed to sling the fuel pump rod out and away from the engine to never never land.

[hawkeyesheroes]

terrible T , you'll get me to connect the dots yet. Today I pulled the fuel pump from a corvair powered dune buggy, and sure enough, there's the pushrod with spring attached in the machined hole of the block leading down to the crank. Now I know whats missing from my 69 engine ! Although it looks like it would be impossible for this rod and spring , it maybe could be carefully dropped in the hole for the oil fill tube . But for it to drop in by accident while I'm carefully trying to remove the oil filter/fuel pump assembly, that's highly unlikely .
I bought this car about 10 years ago in LA, but only drove a few times , had been sitting for years before I got it going last fall and drove into my shop. So when Terrible T suggests looking for an electric fuel pump , I listen ! Sure enough, mounted right in back of the gas tank. So the electric pump pushes gas to the now useless mechanical fuel pump - - useless because there's no push rod to actuate the fuel pump rod-- so even if the diaphragm isn't moving fuel apparently still flows through it and has enough pressure to satisfy the carbs. Seems like an un -necessary step , going through the mechanical pump, couldn't it be eliminated and the rod hole be capped ?

[terribleted]

It can be a dangerous set up. If the fuel pump diaphragm fails it can leak gas into the crankcase. It is best to either bypass the mechanical pump completely (remove and cap the hole perhaps...Clark's and others sell a blockoff plug), or install a false center fuel pump section (Clark's sells) that leaves a stock appearance but replaces the pump internals with a simple passage...no possibility of leaks into the crankcase.

[bbodie52]

I would recommend that you explore your electric fuel pump installation to determine just what has been installed in your Corvair. If it ever fails, you will need to understand the system to properly troubleshoot and repair it. You would also want to know if it is a safe installation or a possible fire hazard. You might also consider returning to a possibly less-costly mechanical fuel pump arrangement. If the existing mechanical fuel pump is functional, all you might need is a little rubber fuel line to eliminate the electric pump, and a push rod for the existing mechanical fuel pump. http://www.corvair.com/user-cgi/catalog ... ow_page=65

FUEL PUMP BY PASS PLATE-STRAIGHT THROUGH WITH ELECTRIC PUMP


http://www.corvair.com/user-cgi/catalog ... IN&page=66


Part number C12879: FUEL PUMP BY PASS PLATE-STRAIGHT THROUGH WITH ELECTRIC PUMP

Weight: 0 lbs 8 oz
Catalog Pages(s): 66
Price: $ 47.25

This leaves many unanswered questions about the details of your electric fuel pump installation.

Do you know if the mechanical pump is still serviceable if a push rod were to be installed? Do you know the name and model number of the electric fuel pump that was substituted? Also, where was the electric pump physically mounted? Mechanical pumps like the original Corvair fuel pump do a good job of creating a vacuum to pull the fuel long distances from the fuel tank. However, electric fuel pumps are better at pushing fuel than pulling it, so the electric fuel pump normally should be mounted as close as possible to the fuel tank, so that fuel is essentially a gravity feed from the source that would only be a few inches from the pump. Then the electric fuel pump pressurizes the fuel line all the way to the engine compartment and carburetors.

A properly installed electric fuel pump system includes one or more safety cutoff switches...

From what I can determine, an inertia switch acts like a circuit breaker. The default would be to permit electrical continuity through the switch unless it has been tripped. This means that there should be a voltage input and voltage output at the switch location, and you should be able to measure 12 V DC with a multimeter at the input of the switch when the ignition key is ON. If you measure voltage going in but nothing coming out the inertia switch may have tripped. There is a reset button on the top of the switch to restore power.

A second safety switch in the circuit is an oil pressure sensor. Most of these have three connectors. One connector is an output that provides power to the electric fuel pump. The other two connectors provide electricity from two sources. One of these allows electrical continuity through the switch when there is no oil pressure. It is normally connected to a temporary voltage source that is provided by the starter solenoid. When the engine is cranked to start the engine, the starter solenoid also provides voltage to the oil pressure safety switch, which passes through the switch and on to the electric fuel pump (but only when the engine is being cranked and needs fuel for initial startup). When the operator releases the key when the engine starts, the starter solenoid disengages and also discontinues providing voltage to the fuel pump. At this point, with the engine running, oil pressure from the engine triggers the safety switch to allow electricity from the ignition switch (and possibly from an inertia safety switch, if one is used) to reach the electric fuel pump.

With this dual safety switch arrangement, the inertia switch would be passive and would normally allow electricity to pass through it unless a sudden vehicle impact causes the switch to open and cut off the electric fuel pump. The oil pressure safety switch only allows electricity to pass through it from the startup source (the starter solenoid) or, when oil pressure is present, from the primary voltage source (normally the ignition switch circuit, which should also be fused).

Obviously, the electric fuel pump system is much more complex than the original mechanical fuel pump system. Possible points of failure include the pump itself, the fuse in the circuit, wiring faults, the inertia safety switch, or a faulty oil pressure safety switch.

The material I found below about the inertia activated fuel pump shutoff switch indicates that this switch has a reset button on the top.
https://www.pegasusautoracing.com/produ ... oCZcHw_wcB

Pegasus Part No. 1108 - Fuel Pump Shut-Off Switch - Inertia Activated

Our Inertia Activated Fuel Pump Shut-Off Switch will cut power to an electric fuel pump after an impact of 10 to 12 G's or higher*, reducing the risk of post-crash fires caused by pressurized fuel sprayed from ruptured fuel lines. Resets with a simple push on the top of the switch.

This is such a cost effective safety item that many production cars have similar switches installed as original equipment. (Note: Although our switch is similar in operation to the switches found on street vehicles, it is not intended to be a replacement for any OEM switch.)

10 Amp continuous load rating allows the switch to handle the current of most electric fuel pumps (such as Facet low-pressure pumps) directly. Fuel pumps drawing 10 amps or more (such as the Bosch 044 and Aeromotive A1000 pumps) should use this switch to break contact on the fuel pump relay coil circuit. Includes switch, connector kit, and full instructions. Installation time averages less than 30 minutes. The kit is a universal fit for any vehicle with an electric fuel pump.

* A "typical" 8 mph fender-bender might generate a 2 g impact. Most OEM air bags are set to deploy in a 7 g impact, equivalent to hitting a solid wall at about 15 mph or a stationary vehicle at about 25 mph.

The inertia switch is a dependable car component, as long as it is in good condition and is working well. But, once it gets damaged, it will be giving you a whole lot of trouble. You may experience sudden dying of your vehicle engine, with no fuel reaching your motor.

Inertia switches can be found in most cars especially those that use fuel injection. Its main purpose is to prevent any dangerous fuel leaks to occur when you get into an accident. It does this by cutting off the fuel supply fed by the fuel pump to the engine. However, a sudden stop or a vigorous change in direction may activate the switch. When accidentally activated, your car might not start or the engine would suddenly die due to the engine being starved of fuel. To remedy this, you can either reset the switch which is fairly easy or, if it's broken, is to install a new one.

https://www.summitracing.com/parts/atx- ... oCPQTw_wcB

https://www.summitracing.com/parts/crt- ... oCxGjw_wcB

The Carter A68301 pressure switch is a single pole double throw diaphragm actuated switch. Terminals P (Pump) and S (Start) are normally closed, terminals P (Pump) and I (Ignition) are normally open. Start and Pump terminals will be active during cranking and the ignition and pump terminals will be active when 7psi of oil pressure or higher exists. All current will be deactivated if 7 plus pounds of oil pressure or the start switch signal is not present. With a 10 Amp rating across the entire switch.

http://www.corvair.com/user-cgi/catalog ... N&page=27D

[hawkeyesheroes]

Thanks again Brad B and Terrible T, all your info is really helpful. Sounds like there's a few options for me : get a pushrod ,see if the mechanical pump works, if not ,replace it . Or check into the electric pump on the car ( know it works , drove car into my shop last fall ), it could possibly need safety switches wired in, and possibly a new electric pump if the present one isn't up to snuff, then block off mechanical pump.
Wonder if you guys have a preference , I value your opinions .
Also want to say , looks like you kids stay up way past your bedtimes !

[bbodie52]

A new mechanical pump, push rod, and spring, adds up to $88.10. If the existing pump proves to be serviceable, it could be retained as an emergency spare and stored in the trunk, providing for an emergency roadside repair.

While installing/retaining an electric fuel pump may be a good option (depending on what you find in your existing system), it is a relatively expensive and complex change that may not be necessary. The factory design of the fuel and ignition systems in the Corvair has been proven to be reliable for decades of operation in many thousands of Corvairs. I would suggest carefully checking the basic system before jumping ahead and trying to resolve the problem with a modification that includes electric fuel pump and associated safety switches.

Part number C259: 62-69 FUEL PUMP ROD-REPRO (3 13/16") REBUILT FUEL PUMP 60-61=CX1617- ROD=C7256

Weight: 0 lbs 4 oz
Catalog Pages(s): 11(28),65
Price: $ 19.10

Part number C1604: FUEL PUMP SPRING

Weight: 0 lbs 2 oz
Catalog Pages(s): 11(34),65
Price: $ 3.45

Part number C3403: NON-GM FUEL PUMP-62-69 WILL FIT 60-61 IF ORDER C259 ROD

Weight: 2 lbs 4 oz
Catalog Pages(s): 65
Price:
1 - 1 $ 65.55
2+ $ 63.60

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Depending on what you have and what you need, here are some prices for some installation hardware and possibly for a replacement electric fuel pump. I have listed some Clark's prices and some prices from alternate vendors...

Part number C12879: FUEL PUMP BY PASS PLATE-STRAIGHT THROUGH WITH ELECTRIC PUMP

Weight: 0 lbs 8 oz
Catalog Pages(s): 66
Price: $ 47.25

Part number C9848: FUEL SAFETY INERTIA SWITCH

Weight: 1 lbs 0 oz
Catalog Pages(s): 66
Price: $ 83.35

(Pegasus Fuel Pump Shut-Off Switch - Inertia Activated, P/N: 1108 - $59.99)


Part number C5607X: SAFETY SHUT-OFF SWITCH WITH FITTINGS TO ALLOW USE OF STOCK OIL PRESSURE SWITCH TOO

Weight: 0 lbs 10 oz
Catalog Pages(s): 66
Price: $ 44.05

(Airtex OS75 - Airtex Oil Pressure Safety Switch - $14.97 or Carter Oil Pressure Safety Switch A68301 - $17.97) plus
Part number C7521: ADAPT-A-BOLT-STOCK FILTER* IF USING W/ OIL TEMP SENDER-NEED TO DRILL ADAPTOR DEEPER

Weight: 0 lbs 6 oz
Catalog Pages(s): 27D
Price: $ 24.90

SAFETY SHUT-OFF SWITCH WITH FITTINGS TO ALLOW USE OF STOCK OIL PRESSURE SWITCH TOO: $39.87

Airtex External Electric Fuel Pumps E8016S
$27.44
https://www.summitracing.com/parts/atx-e8016s


Facet Cube Style 12 Volt Fuel Pump, 3 to 4.5 max psi
Part No: FAC-40105
$48.99
https://www.pegasusautoracing.com/produ ... oCJ_jw_wcB

I have found the Corvair mechanical fuel pumps to be very reliable (I have yet to have one fail, and I have been around Corvairs since 1961). Since they are unique in design for Corvairs only, keeping a spare mechanical fuel pump in the trunk might be wise, since they are unlikely to be in stock at most auto parts stores and having a spare on-hand can make a relatively simple roadside repair possible.

The Airtex and Facet electric fuel pumps previously mentioned are also of high quality and highly reliable. They are electromechanical in nature and can still fail. The installation of an electric fuel pump adds some complexity to your fuel system, and pressurizes the fuel line all the way from the fuel tank to the engine compartment (electric fuel pumps are generally designed to be installed close to the fuel source, and do not function very well if they are installed a long distance from the fuel tank). A safety switch should be included in the installation so that electrical power to the fuel pump will be cut if the engine dies (switch triggered by engine oil pressure). A fuel filter at the electric fuel pump inlet is also a good idea.