Djet running way too rich... Still! Options

[Halfnelson]

Had a previous thread starting in 2022 about my 73 1.7 standard D-Jet running way too rich and flooding to the point where it wouldn't start. It's been an ongoing issue. I've had a go. 2 garages have had a go. I'm at the point where I'm beginning to lose hope.

A recap. Bought the car 2021, had a problem with intermittent flooding. So far have:
Checked MPS - holding vacuum.
Replaced CHT sensor and tested. Working when flooded.
Replaced fuel pump and tested pressure.
Replaced all vacuum hoses and tested for leaks.
Valves set and rechecked.
New 123 distributor.
New injectors.

Each time I think I've cracked it and it runs and drives - sometimes for a month or so. Then I'll go to start it and it'll flood again to the point where it contaminates the oil. I feel like I've never managed to get to the bottom of the problem. Just keep replacing parts. Thinking maybe a return line that intermittently blocks? I'm kind of at a loss.

[Ishley]

It sounds a lot like you're having ignition and spark issues. I chased a lot of issues before I realized I had a spark plug wire issue that would intermittently cause misses.... and my car would run very rich. Chasing down problems and checking plugs etc.... I would move the suspect wire... and then it would run fine... for a while. Sometimes if you're lucky... it's the simple things.

Another issue I had earlier... was the seating of the 123 Distributor. The my unit came with a spacer ring... which I added... and I found that to be a problem. Once I removed it... it seats better and is really locked in place.

Also... with the 123 Distributor.... make sure the two wires that are connected to 914 harness are making solid connections.

What are your plugs gapped to? Too small/big and you can have misfire issues... The 123 with the right coil should give you a healthy fat spark. Do you replace your plugs after a rich running cycle? They could be fouling over and over... and slight misfires will appear as rich.

Is your coil good? Do you have the correct one for the 123 distributor?

Another issue could be the Throttle position sensor. It underneath the throttle valve. There is an adjustment procedure that needs to be right. If the adjustment screws are not holding it firmly in place.... you can get weird issues. This can be replaced too.... at the very least make sure your injector harness is solidly connected to the TPS.

Do you have a fuel pressure gauge installed in the engine bay? I would recommend it and make sure you have a consistent rate of fuel. Easy install and worth knowing where your pressure is at.

The MPS rebuild could be your issue... I did mine... but in my opinion....you're are moving into a complex area with this... and the tuning afterwards can be complicated and is really best done with a Wideband O2 sensor installed in your exhaust and an Air Fuel Ratio Gauge that is wired to a dash gauge for monitoring. I would make sure everything else is working right first before I jumped into this.

Check and recheck all the easy stuff with your Ignition system. Your clearly getting fuel.