desertdatsuns.net

I also did Duffman's mod, but in my case it turned out the issue was hatch seals, taillight gaskets, and carb adjustments.

An update to my EFI upgrade on the Scarab:
On my first real shakedown run up to Star Valley for breakfast the car ran great. On the way home though it just quit and had to coast into the Chevron station at the edge of town. Did the quick checks and found no spark. Called a friend to come pick me up, loaded the car on my trailer and rolled it into the garage where it had to sit for a couple weeks while I completed installing laminate flooring in the back bedroom (two more rooms to go.)
When I completed that honey-do I did some more troubleshooting and found there was spark coming from the MSD to the coil but no signal from the EFI to the MSD. Called Holley tech support, they said send it in, sounds like a component failure.
Well, they called me back and said they were sending a new unit rather than repairing. Cool!
In the meantime I removed the seats, rewired everything to do with the EFI to minimize RFI and EMI: move MSD from under passenger seat to driver footwell, moved Safeguard from passenger footwell to driver footwell, rerouted vacuum line for Safeguard from the Alky MAF to the boost controller. Now all power wires are thru one firewall hole, the signal wires are thru another hole and the coil wires are thru a third hole. Lemme tell ya, I'm getting too old to be spending hours on my back under a dashboard!
Got the new Sniper Thursday, installed Friday, fired up today on the first turn of the key. WHOO-HOO! Took a quick lap around the neighborhood. Now, fingers crossed there's no more component failures during burn-in.
Solvang here we come!

No more component failures!!! Sounds like you made some good progress while waiting though, Bob. Did you mean no more failures during "burn in" or "burn out"? See you next weekend in Solvang.

SCARZME wrote: ↑Sat Apr 23, 2022 5:49 pm . Called Holley tech support, they said send it in, sounds like a component failure.
Well, they called me back and said they were sending a new unit rather than repairing. Cool!
to minimize RFI and EMI:

Holley support is pretty awesome usually.

I have installed dozens of their Sniper / Terminator EFI units and it is amazing how sensitive they can be to EMI/RFI. I think the shape of the engine bay actually comes into play too - I had installed a Sniper setup on a '37 Chevy Hot-Rod Truck with a 350SBC in it - and I did my usual due-diligence on making sure nothing was ran near the coil, spark plug wires, alternator, starter, and that the power/ground were ran to the battery - however I was still getting symptoms that were the same as RF/EM interference. I ended up buying a set of near-field probes for my oscilloscope and had several hot-spots that didn't make sense. My best theory is that the narrow trapezoidal shape and the domed hood were basically focusing/concentrating the EM/RF interference and causing the issues. I ended up using some shielded wire, shielded spark plug wires, and lining the underside of the hood with RM/EM absorbing material from a company called TrueSpec (probably overkill, but oh well.) Solved the issue, ran great afterwards.

I did quite a few custom Terminator setups and always ordered additional shielded sensor wiring harness kits from Holley for cam/crank sensors. Also, the Holley EFIs really hate magnetic sensor based distributors. Issues may not manifest themselves for several hundred miles - but they will start cropping up with a magnetic sensor distributor. If you are running the typical SBC MSD distributor with the magnetic pickup (Street-Fire, Pro-Billet, Ready to Run, etc) then I would seriously consider going to one of the holley branded sniper hall effect distributors - even more so if you are going to allow the ECU to control timing. The most annoying part is when they first came out with their systems, they didn't realize the issues the magnetic sensors cause - and had instructions pertaining to wiring them up. Later, they dropped that from the manuals and added the "we don't recommend using magnetic pick-up distributors" disclaimers. I think I had installed 6 or 8 of them at that point - all using the customers existing very common MSD distributors.

The Holley systems are IMO the best, I have installed many FiTechs and similar and had QC issues.

installed new water pump, 7 blade fan, pulley, radiator and shroud and fuel pump on my 521

Doing the same on my 620. Have to figure out how to separate the fan clutch and pulley from the water pump. Appears that it is pressed on and though the water pump is junk, I don't want to damage the clutch and pulley.

I got the rudder attached and working.

Chuck, that rudder must look sharp on your Z, am sure it will help you move down the road!!

Weather finally cleared up enough to do more troubleshooting of my Holley Sniper EFI issues on the Scarab. Kept getting a learning table telling me I needed 25-40% more fuel as I got into boost. But when I copied the learned values into the fuel table and drove again, it still wanted more fuel! What the...? So, either the stroked motor is making way more power than I thought and the EFI can't keep up. Or, the fuel pump can't keep up with demand. Or, the fuel pressure regulator isn't maintaining pressure thru the RPM and Boost range. But a rough calculation of HP at 10 psi boost says I can't be making more than 500-525 and the Sniper is good for 600 it's unlikely it's the issue. The pump is good for 360 lph which is more than max demand for that HP. So, the fuel pressure regulator is the only thing left to look at. But I had no way to monitor fuel pressure from the driver seat. And fuel pressure gauges that can be mounted in the passenger compartment are several hundred dollars. I had to come up with another alternative. I dug around in my parts stash and came up with a spare Methanol line and fittings that would allow me to mount a fuel pressure gauge where I could see it while driving but outside the interior. So I came up with this:






I used a scrape piece of AL to fab a mounting plate and used the holes for the access panel to mount it and voila, a remote gauge I could monitor while driving.
Pressure was fine driving through town but as soon as I got out on the highway and rolled into the throttle, pressure started falling off until it got down to 20 psi as boost came in. Yikes! Pressure is supposed to stay steady until boost comes in and then increase pound for pound. Well, found the problem!

Ordered a new Fuelab mini regulator and fittings good from 25-90 psi ($215 from Summit), installed and road tested after the weather cleared up AGAIN. And now pressure is steady and increases under boost. Tested with 5 psi, now ready to increase to 10 and leave that as my max boost setting.
Learn table now shows a reasonable deviation of 10% maximum at a couple spots. SWEEET!
Now, gotta tweak the Methanol injection to the right level and hopefully it will be happy for a while.

Nice work Bob!