76 280z microsquirt project

[calZ]

What is the name of the company selling brand new timing covers?

[darom]

Hi CalZ,

It is https://www.amayama.com/en

 

[darom]

After priming the engine oil and starting/warming up the car, there is a small leak around the rear main seal. It is either my side seals or the rear main. Considering how easy it is to bump the seal while installing the rear cap, I wouldn't be surprised.

I guess it is time for a tranny drop operation. I will check with my endoscope.

[darom]

It was the rear main seal leaking, I removed the transmission and could clearly see the oil around the seal:

[darom]

Installed a set of OEM engine mounts. They are still available, the cheapest ones are shipped from Japan (ebay source), about $120 total.

 

Originally, I figured I would save some money  and ordered a $20 special for a pair + s&h. Then I found some posts on classiczcars about their poor fitment, SAE threads (not with the pair I purchased), misaligned locating pins etc. 

Here are some pictures for comparison. The center bolt is longer on the after market one:

The locating pin is way off:

 

The OEM mounts fit like a glove, no issues.

 

[darom]

I also decided to re-address the lean condition on hot restarts. When it happens, the fuel pressure would bounce around, 18 - 22 psi. The FPR is set to 37-38 psi (w/o vacuum), at idle normal psi is around 31-32 psi with the vacuum attached. The FPR is an Aeromotive unit.

 

Started with the fuel pump's (Walbro 255) voltage.

1. My original design - battery -> circuit breaker -> microsquirt's fuel pump relay -> main relay -> 30AMP relay (Inertia switch) -> Fuel Pump

All wiring is 14 gauge. The voltage delta between the battery's and the fuel pump's was 1.5 Volts!

2. Re-did the ground - dedicated negative to the back panel's ground point where the tail lights get grounded. The delta was 1.2 Volts.

3. Installed a dedicated FP relay in the engine bay (Tyco 75Amp, with a 25amp fuse), with direct run to the fuel pump. The microsquirt's relay provides a trigger on post 86, inertia switch (in cabin) - ground. The delta is 0.3 Volts. Here is a diagram:

 

Another possible issue might be related to the pre-pump's G3 Fram's filter being too restrictive (40 micron).

Installed a 100 micron pre-filter:

The pump is very quiet.

 

The hot restart ends up with 14-15 AFRs for about 40 seconds, then it scales back to my pre-configured 13.5 at idle. I don't see a lot of fuel pressure fluctuations any more.

 

As a precaution I added a 1979's 'hair dryer' to cool my injectors. I found it at a junk yard. I am using a time relay board which is set for 15 minutes. When I park the car, I can engage it from inside. I will test it on a hot day:

 

 

 

Edited 3 hours ago by darom

[darom]

My current issue is with leaking oil and coolant. My head gasket is leaking coolant - this is between cylinder 1 and 2 on the RH side. I can see the coolant right at the edge of the engine/cyl head.

 

When I installed the new timing cover, my head gasket got torn at the top. I made a gasket and used some aerobic silicone. The oil is leaking a little on both sides. 

 

The plan is to remove the cylinder head, take it to the shop to get it reconditioned (new stem seals, check the springs etc), put a new set of ARP stud fasteners with an OEM gasket. The new gasket will also stop, hopefully, the leak at the top of the timing cover.

 

I checked the prices on the Nissan head bolts - they are in the hundreds now. Not sure what happened. The MSA is basically recommending to go cheaper ARP route (which used to cost more in the past, now it is reverse).