So time for another update. D4C has come and gone, so I have a bit more time to continue with small progress (hey I warned that it would be slow!).
I started driving this car to work and have put approximately 1000 miles on it. To start with, I was mainly tuning the mixtures and experimenting with the FQS switch.
Where I have it now seems to be reliable and I haven't touched it for over a week. First, I jumpered the TPS to the harness, only connecting the GRD (middle pin) and Idle pin. For the moment, WOT is not used because I was getting super rich conditions while under vacuum and full throttle.
**Slightly adjusting it seemed to help, along with cleaning the ICV and Throttle body with carb cleaner-- highly recommended**
The FQS switch is set to Position 0 or 2, which is either standard or -3% fuel. I think this just adjusts the duty cycle of the injectors slightly and holds them closed. This gives me idle AFR's of 14.7-15.3 depending on ambient temperatures.
The RRFPR is set with the gain needle all the way out, and the center screw maybe 2/3's of the way out. However, I found out that I don't have the restrictor required for this device, so I may need to continue tweaking when I install the new turbo.
Last night, I installed a Walbro GSL392 inline pump in replacement of the stock external pump. I like reversible modifications, so if I ever wanted this could be reverted back to a standard Bosch pump, or it could be repaired on the side of the highway if ever needed.
I found a great write up on the subject, which I will save and share below for somebody else's future reference.
Follow the pictures how to swap from your old 130lph vane type inline pump to a modern 255lph gerotor design from Walbro that flows more at the same pressure. The gerotor squeezes fuel from in between to gears up to your rail versus being pushed with the old vane style. This allows the pump to be small, light, quiet, etc. Everything you want to ease your mind while zipping down the road.
First step it to verify you have all the tools and knowledge to do such a repair. This entails safety glasses, wheel chocks, hoses, drivers, clamps, etc.
Here is what you need:
1 - Walbro 255lph inline fuel pump (I used Walbro GSL392)
1 - 8mm barb - 10mm x 1.0mm male (Walbro P/N 128-3024)
1 - 12mm barb - 10mm x 1.0mm male (Walbro P/N 128-3025)
1 - Few meters of 8mm x 13mm fuel house (BMW P/N 13311722262), 5/16" works fine.
1 - Meter of 12mm x 18mm fuel hose (BMW P/N 16121176440)
1/2" will work IF you can locate high pressure EFI line.
1 - New hose clamps, ABA or style that does not cut into hose
1. First, secure car on ramps or jack stands and chock wheels. Disconnect fuel pump relay when vehicle is running (if you have it) or let pressure bleed off after a few hours. Then identify the fuel pump beside the filter.
2. Here is your new high volume at high pressure Walbro with fittings installed. 12mm on side to lift pump, 8mm on side to filter.
3. Next, go ahead and disconnect the old fuel lines. You will spill fuel, so put that stogie out and locate a suitable container to catch this fuel.
4. Remove 10mm bolt from bracket and nuts that secure power wires. Should be 7mm and 8mm.
5. Compare new pump to old. You will notice that the dampening unit needs to be swapped over. You need simply a short length of 12mm x 18mm line, around 2".
6. Loosely tighten clamps on dampening unit and new hose. This device can be removed, is so, just replace with an elbow fitting, or run the large fuel hose straight to the pump.
7. Slide new pump into position. Attach lift pump hose to dampening unit and pump supply to fuel filter. Attach pump wires, brown is ground and green is 12V.
8.. New lines at lift pump. I cannot show with pictures what to do, but simply slide the new lines down the top of the tank and they will come out the opposing side. Cut to length.
Jump fuel relay and verify no leaks. If none found, go ahead and start the vehicle on up with extinguisher handy. Let idle for a few moments and go over all connections as vehicle idles.
If all checks out okay, lower car from ramps or stands and wash up. Congratulate yourself as you now have sufficient fuel supply to make massive power and one less headache to worry about.
The old pump had been having issues at 5+psi boost of going slightly lean. It was strong otherwise, and will remain a backup for my other two NA cars. I think it was not able to keep up with the higher pressures at the required flow rate as asked by the RRFPR. Static, it was good to 80, but in the required condition, it seemed to be limited to about 60psi. Somehow, the bracket had been missing some hardware, allowing both the pump and filter to wiggle freely, held in place only by the fuel line. I was able to round up the required hardware and mount both properly and secure it all.
I need to continue some tuning as now the AFR's are a bit too rich (10-11) when approaching atmospheric and 1-2psi. I realized I needed to install the restrictor to delay this rise in the BEGI 2025. Since mine didn't come with one (Bell references P/N: F2815-301), I will use a smaller I.D. vacuum line and see if that helps.
I only drove it around the block, but initial trials suggest AFR's of 12.5 in 3rd gear under boost. Excellent. Before, this was the point where the numbers would go lean and the stock Bosch pump couldn't keep up.
Next up will be to continue 'shakedown' progress of the car. In the near future, however, I will plan to upgrade to the TCD 60-1 turbo--I was waiting partially for the fuel pump, but also pending results of daily use.
Sort of reserving the use of the WOT signal, in case the RRFPR can't keep up with the flow capability of the new turbo. Will explore more at that time, but the idea would be to use a 1psi pressure switch with 8psi check valve that opens when the RRFPR can't keep up. Then the WOT signal means the ECU opens the duty cycle of the injectors to get 20% more fuel when at 8psi+.
I have a small leak on the valve cover, by the ICV. It seems like coolant/oil, but is always gone by the time I look at it in the morning. I think the Valve Cover Gasket is leaking coolant, so I may do a valve adjustment and valve cover gasket first, before changing the turbo.
yea right!