1961 320 unit Need FI Help

[Richard M.]

Re: 1961 320 unit Need FI Help

Willie, When the high pressure pump had it's leak, did the engine have the same starvation problem?

If you suspect the primary fuel pump, you could remove the line from the FI unit and do the cranking test(coil wire off) for fuel pressure. IIRC you want around 6-8 psi coming out with consistent flow.

John D? Is there any way to test the high pressure pump when it's installed in the unit.....edit....(on the engine)? Chuck taught me how to test flow when the unit(plenum) is on the bench, observing flow out of each nozzle while running the pump with a drill. But I'm curious if it can be checked any way on the engine. Could you disconnect the HP pump output and run it to a test gauge?

Rich

[Willie R.]

Re: 1961 320 unit Need FI Help

Yes before the leak, have not had a chance to check the fuel pump.

[John D.]

Re: 1961 320 unit Need FI Help

Question was asked as to how do you get the epoxy out. I have a large hand reamer for that. Fits in the bore of course and is gauged to the step in the bore where the seal goes.
I clamp the reamer in a vise. Reamer is verticle. I then put the pump on top/in the reamer and slowly turn the pump. Cuts the epoxy right out of there without doing damage to the bore. Not for the young at heart.
But then gang you may be left with a huge gouge in the bore. What's next you ask. Well either find a machinist who will make you a sleeve or use epoxy again to install the seal. Sounds like a bubba job but other than that get another pump.
Richard, I don't have a way to test the pressure of the pump. I just run it while flow testing. No setup for disconnecting the HP pump output to run to a test gauge.
Gail Parson once started this project but wasn't able to complete it before he passed on.
Jerry Bramlett was working on this idea. I don't know if he accomplished it or not. Have to ask him. John

[Richard M.]

Re: 1961 320 unit Need FI Help

Thanks for the info John.

What is the pump output pressure spec? Is there a minimum spec?

Rich

[Jim L.]

Re: 1961 320 unit Need FI Help

Thanks for the info John.

What is the pump output pressure spec? Is there a minimum spec?

Rich

Rich,

The high pressure pump is of the positive displacement type. This means that the pressure will rise to whatever it needs to be to sustain the flow defined by the volume between the gear teeth and the rate of rotation. Of course there will be some leakage past the tips of the gear teeth and along the sides of the gear teeth. That's unavoidable.

However, if the gear side clearances are less than .001 (I often shoot for .0005) and if there is no visible gap between the tips of the gear teeth and the gear cavity, the pump is fine. No need to try measuring flow rate or output pressure (which is a meaningless number).

Jim

[Richard M.]

Re: 1961 320 unit Need FI Help

Thanks Jim.... You know I'm new at the FI troubleshooting and I'd like to learn how to fix them. I'm wondering if that's Willie's problem, as he says he got a fuel starvation issue. He's suspecting his engine fuel pump may be a problem and he's going to test that.

Thinking about it...I'm wondering if he has a different problem, like vapor lock or something else totally unrelated to the FI unit.

Rich

[Jim L.]

Re: 1961 320 unit Need FI Help

he says he got a fuel starvation issue. He's suspecting his engine fuel pump may be a problem and he's going to test that.

Rich

I'd certainly look suspiciously at the engine pump before I'd worry about the high pressure pump. The high pressure pump has enough flow capacity to deliver twice as much fuel as the engine needs at wide open throttle. IOW, It can have significant wear and it will still function.

As to the torque needed to turn the pump, my memory is that the factory acceptance criterium was 20 ounce-inches or less. In any event, a rebuilt pump should turn smoothly, no rough spots, and should turn relatively easily. If you can turn the pump by hand using a drive cable inserted in the shaft, the torque is in the right ball park.

Jim

[John D.]

Re: 1961 320 unit Need FI Help

Hi Pressure pump info for the 5630006 pump (most common FI pump from 58 to 65.)
Remember the pump runs at 1/2 engine RPM
RPM. Fuel Flow. #/Hr
250..... 27#........ 7.25PSI
500 .... 41#..........17PSI
1000.. 82#.......... 71PSI
1500.. 124#....... 165PSI
2000.. 158#....... 305 PSI
3000.. 196#....... 415 PSI
3500 .. 208#....... 680 PSI
The above info was taken from a Rochester Products print. That pump puts out some serious pressure folks. Some say over engineered. But I don't agree.
Lately more fuel injection problems are occuring because some pumps are not putting out the pressure.

Here's one for your FI guru's. Maybe you already know this. I think Jim Lockwood knows
My 63 LWC has a NOS hi-pressure pump. It's not black but a plum color. When I was putting a viton seal in my NOS pump before the Seven Springs Regional I called Gail Parsons and told him of a problem with the pump. The clearances aren't as tight as the OEM pumps. Once again a NOS part we pay major bucks for only to find out it's just a service replacement pump.
When rebuilding a pump (not my favorite job for sure) remember to lap the end plate flat. Use a granite surface plate and find sandpaper until you remove all of the gouges, etc.
The NOS pumps have a 1 thosands clearance beween the gears and the spacer. Means the spacer is about 1 thousand higher than the gears.

The original pumps have only 1/2 thousand different!!!!
So I said to Gail my pump that I horded for an eon had some really wide clearances. He said he was fully aware of that and told me to put it on and it should work fine.

If you see a pump that has some lead melted into two of the allen head cap screws and the lead has some initials in it then you hit pay dirt.That pump has never been apart. Never been butchered. A piece of cake to rebuild. John