Car stalling AGAIN, Updates- none of them good. Options

[rjames]

Drove around for 30 minutes in 80+ degree weather. All arterial roads, so several stop lights, etc. No problems until I was almost home. Car stalled when I stopped at a light. RPMs just dropped to zero. Was able to start it again with a little difficulty and had to keep my foot on the gas to keep it from stalling out again. Power seemed ok though the rest of the way home (I think). It stalled once again at a stop light a couple of blocks from home and then again when I pulled in the driveway. I let it sit for 30 seconds, started it again and it idled just fine. Rock solid at 1000 RPMs. Pulled it into the garage where it sits now.

Prior to today the car has been running and idling perfectly since I went through the FI parts last year, which included installing a 123 distributor, new CHT sensor, a newly rebuilt mps (calibrated for correct afr on my engine), new vacuum hoses, NOS throttle body, rebuilt injectors, new fuel pump, valve adjustment and timing.

I haven’t checked the AFR since last year, not sure why it would change though.
It’s a ‘75 so the fuel pump is in the front, so I can rule out vapor lock I think.

Anyone have ideas as to why it would be stalling?

[yellowporky]

It seems like 2 different things happening here.
The surging from what i understand tends to be a lean issue typically caused by a vacuum leak and the stalling would tend to be a heat related electrical issue.
How do the spark plugs look? Are they all colored tan or is one or more white?

Do not assume anything is good until you 100% rule it out. Go to 914 rubber and buy all of the vacuum elbows, connectors, TB gasket, cold start injector gasket ect.. Auto Atlanta has a good vacuum line kit too, Put clamps or good zip ties on the plenum to intake runner hoses and also it is not unheard of to have a crack in the plenum itself.
Check the intake nuts for proper torque too.

For the electrical issue make sure as stated above, remove and clean the 3 prong ground for the FI and then go to every other ground one by one and do the same.

Hope you find it soon. Unfortunately this is how most of us learn about these cars.