Deciphering Fuel Enrichment Relay Setup

[Flash66]

Hey critical, what manual are you using for turbo routing? Thanks!

[David T]

Quick update to close the loop - it’s been a busy few weeks but I finally had time to sort everything out and install a new fuel pump while I was at it. For some reason or another I was getting suspicious that I was losing fuel pressure shortly after my last post. I know the accumulator was replaced by the previous owner, so I decided to take a look at the fuel pump and found there was no pump cover and the boot was filled with gas or water...or water that smelled like gas. I wicked it out with a rag, but decided to just replace the pump as it was original and the electrical contacts were rusted beyond repair. While I was waiting on that, I decided to dig into the valley to install my new silicone vacuum hoses. It wasn’t too bad down there but I did need a new heater pipe and a few new hoses. Took the plunge on a new water pump too, again b/c I figured the original was on borrowed time. Got everything back together last weekend, including the new fuel pump. The old vac lines were pretty brittle in the valley and I must have had a leak somewhere b/c the car now idles better than ever. I now have the vac lines routed according to the turbo manual. Even though the idle sounded good and the dwell was between 35-45, I noticed the engine stuttered on acceleration up to 25k rpms in all gears. Double checked everything - wires, injectors, plugs, fuel pump hoses and connections. Ultimately, an ever so slight adjustment to the mixture seems to have cleared things up.

For now, everything seems good - fingers crossed things stay that way!

It's OK to run a bit richer because of the Turbo kit. In fact, under boost you may find you run lean so there are modifications that can be done to "trick" the CPR into giving more fuel under boost. While you are checking things, check the base timing and the mechanical and vacuum advance. Use the highest octane fuel you can find too. NEVER let the motor have detonation during boost. It won't take much to blow the pistons! Make sure you never exceed 5# boost. Adjust each wastegate actuator if necessary.

[Flash66]

Hey David, Can you elaborate on the CPR "trick"for me? I'm installing a newly rebuilt BAE Rajay including an upgraded Turbonetics modern wastegate with a #5 spring installed. The diaphragm was bad in the original Rajay wastegate so I had to find another solution. I have the pin 11 or Lambda trick with WOT or Hobbs, but curious about what you've mentioned. Sorry to hijack but may be beneficial knowledge to both of us. Thanks!

[CriticalB]

Hey critical, what manual are you using for turbo routing? Thanks!

There's a guide here in the resources section for the Island twin turbo kit, which is what I have. It calls for the removal of the vacuum solenoid and redirection of the hose connected to the left intake runner to go to throttle body adapter that replaces the w pipe. Then the tap on the intake runner is connected to the vacuum advance on the distributor. A PO had done several modifications. The warm up regulator was capped on one side with no vacuum delay valve. No idea what that was supposed to achieve. Both the WUR hose and solenoid hose from under the intake manifold from were capped. So to fix all that I installed all new silicone vacuum hoses according to the stock setup, then made the modifications from the turbo guide. For peace of mind I labeled the hoses from the thermal control valve, which has saved me several headaches. There was also a fuel enrichment relay that, according to some notes that were passed along with the car, would disengage the O2 sensor and trigger open loop when boost was detected. However, someone had modified that to activate the CSV under boost, so I switched that back as well. I also got the boost and a/f gauges working, as it appeared some of those changes above had left them non-functional. Oh, and I did confirm the wastegates are set to 4- 5#. Hard to tell exactly as the gauges are mounted on the left knee pad and when you're hitting boost it's not a good time to crane your neck around the steering wheel to watch your gauges. I've given serious thought to rigging up a go-pro to get a good look at what's happening on those gauges later.

[David T]

PM me with your e-mail address and I can send you what I have. For the gauges use a pod and attach it to the "A" pillar. Then you can see them.

[FABombjoy]

You're running the stock O2 sensor, right? You won't get much useful data from that anyway. Narrowband gauges just let you know if you're teeter-tottering around 14.7:1 AFR and not much else.

You do want to be richer under boost but you don't want to be excessive. K-Jet can deliver a ton of fuel and you can easily see AFRs lower than 10:1.

David is alluding to a method where you use the control pressure regulator to enrich under boost. Inside the CPR is a diaphragm and a vacuum chamber on each side. If that diaphragm moves up, control pressure is increased and the mixture leans. If it moves down, control pressure is reduced and the mixture richens.

Legend Industries proposed a system using vacuum switches & vents to pressurize the appropriate port under boost and then bleed the pressure out of the chamber when off boost. This was done to preserve the warm-up enrichment function as well. Plumbing gets complex when you're trying to double-duty the WUR to give both cold enrichment and boost enrichment.

I had a UTCIS-PT which allowed programmable changes to control pressure. I don't recommend it. It doesn't correctly handle warm-up on our cars no matter what the company tells you.
If you want to keep K-jet but would like to log & program it, there is the FrankenCIS. This is the ultimate K-jet solution as you could actually see what the fueling looks like under load and make changes as needed.

[CriticalB]

For the gauges use a pod and attach it to the "A" pillar. Then you can see them.

But then I'd have a pair of 2 in holes in my knee pad...I wonder if there are any gauges out there that use Bluetooth to display a virtual pod on an app on your phone? Far less permanent and more customizable...

[Flash66]

But then I'd have a pair of 2 in holes in my knee pad...I wonder if there are any gauges out there that use Bluetooth to display a virtual pod on an app on your phone? Far less permanent and more customizable...

I'm in the boat with you! There's the "Torque" app that will do this for boost and AF but only for OBD2.

[FABombjoy]

There are multiple wifi or bluetooth systems available but nothing plug & play.

I previously used an LC-1 / AuxBox combo to log AFR, RPM, lambda d/c, and MAP. Those have a BT solution.

14point7 iDash

AEM X-wifi

FrankenCIS + Microsquirt would get you the standard Megasquirt-compatible adapters and anything that works with CANBus

I have an internal BT module in my MS3X box. Also currently running digital WBO2 and vac/boost gauges (placed on top of the center console) but plan on replacing them with CANBus gauges so I can change the displays to different sensors.

[David T]

But then I'd have a pair of 2 in holes in my knee pad...I wonder if there are any gauges out there that use Bluetooth to display a virtual pod on an app on your phone? Far less permanent and more customizable...

Well, you could just put some round covers over the holes, try to repair and recover it, or get another kneepad. Putting the gauges into a double-pod IS the way to go.