Patton Machine Fuel Injection

[SteveJ]

Well, I took it for the first test drive. It ran, but it did not run well. At times it seemed like it was fuel starved. I'm going to re-orient the fuel pump to see if that helps some. 

The plugs were fouled, so I replaced them.

The car does not like to idle. I opted to add an Idle Air Control Valve in case I added AC later. I just ordered all of the parts I believe I need to install the IAC valve.

I let Rick Patton know the results. I haven't tried to datalog anything, yet. That might happen tomorrow depending upon how well the fuel pump repositioning goes.

[Patcon]

14 hours ago, SteveJ said:

Well, I took it for the first test drive. It ran, but it did not run well. At times it seemed like it was fuel starved. I'm going to re-orient the fuel pump to see if that helps some. 

The plugs were fouled, so I replaced them.

The car does not like to idle. I opted to add an Idle Air Control Valve in case I added AC later. I just ordered all of the parts I believe I need to install the IAC valve.

I let Rick Patton know the results. I haven't tried to datalog anything, yet. That might happen tomorrow depending upon how well the fuel pump repositioning goes.

Is this a self learning system or do you need to program it? If it's not self learning then I wouldn't mess with the fuel pump unless I was sure it's starving for fuel

[SteveJ]

It's a late 80's/early 90's GM EFI system, so I would any self learning is limited. I don't recall anything about self learning on the website, either. The fact that I could back off slightly (under load) and get the car to respond leads me to believe there is some kind of lack of fuel for a brief period...that and the bucking.

[Patcon]

I have done some tuning on those years of GM vehicles. They have the ability to adjust the fuel base on the values in the fuel map and O2 input but it's limited. You will need to data log and adjust from there. Be careful and dont spool it up until you get the fueling closer.

[SteveJ]

I also don't like how the fuel lines ended up at the TBI adapters. 

Look at the bend in the line at the front throttle body. (I almost typed "carb".) Rick confirmed the fittings are 1/8 NPT, so I ordered 1/8 NPT to 6AN 90 degree elbows. Then I'll put another 90 on to point to the fuel rail. Hell, I have plenty of braided hose, still.

[Patcon]

Yeah, that could be smoother

[SteveJ]

I got 6AN to 1/8 NPT fittings to replace the barb fittings on the TBI adapters. I could not put the back throttle body fitting at the angle I wanted because it was hitting on the base of the adapter before it was to the point I wanted, so I compromised. It looks a little kludged, but it doesn't leak. (If it looks stupid but it works, it's not stupid.)

I also purchased a Walbro GSL395 fuel pump. This fuel pump is rated up to 20 PSI and is targeted for GM TBI systems. In other words, it's a good application. In addition, it takes male 10mmx1 fittings, so I got it with 6AN to 10mm fittings. After that I put 90 degree elbows on the inlet and outlet and 5/16 to 6AN fittings on the elbows to go to the fuel lines. I was able to orient the pump so the inlet is on the bottom, like it should be. I got the fuel pressure set, and I got a smooth idle, though it is at 1200 RPM. Now I have to test. That might have to wait until Tuesday, though.

 

[SteveJ]

Well, I tested the car this morning. It doesn't like starting smoothly, but once it got going, it ran nicely...for a while. I was going up a hill, and it started losing power, like fuel starvation. I decided to add fuel, almost 7 gallons. It drove well on flat roads (little elevation change), but on a rise a few miles later, I felt the loss of power again. The road leveled out, and I made a right turn. Again, under load, it didn't have enough fuel.

I'm going to change the fuel filter and increase the pressure a little on the fuel rail. I have also started researching surge tanks just in case. 

[kstewart]

I plan on using the Edelbrock surge tank, pump and pressure regulator all in one for my system.

https://www.edelbrock.com/adjustable-universal-efi-sump-fuel-tank-assembly-67gph-35-90-psi-36032.html

Also, is your fuel tank for sure clean?  I've been having issues with cutting out lately and I think it's sediment in my fuel tank that clogs the screen on the pickup.  I'm planning on dropping the tank and having it repaired this fall.

[SteveJ]

It wasn't having issues before the conversion. I drained the tank completely a couple of years ago for the bumper conversion, and I didn't notice much in the way of debris in the gas I drained out. Of course, when I look at the filter carefully post change, my opinion of the condition of the tank could change.

[jonbill]

Well, I tested the car this morning. It doesn't like starting smoothly, but once it got going, it ran nicely...for a while. I was going up a hill, and it started losing power, like fuel starvation. I decided to add fuel, almost 7 gallons. It drove well on flat roads (little elevation change), but on a rise a few miles later, I felt the loss of power again. The road leveled out, and I made a right turn. Again, under load, it didn't have enough fuel.
I'm going to change the fuel filter and increase the pressure a little on the fuel rail. I have also started researching surge tanks just in case. 

Sounds like a simple case of the map not supplying enough fuel as you start to put it under load.
Increasing fuel pressure will make it richer everywhere - doesn't it offer more precise tuning?

[SteveJ]

1 hour ago, jonbill said:

Sounds like a simple case of the map not supplying enough fuel as you start to put it under load.
Increasing fuel pressure will make it richer everywhere - doesn't it offer more precise tuning?

Thanks for the input. It does have the ability to datalog. I haven't done that, yet. I still need to change the fuel filter. I can't remember if I changed it when I did the bumper swap. If I didn't, it's been on there a while. Then I can do the datalogging. After that, I can send the info off to Affordable Fuel Injection for a different map.