Problem Resolved [was I'm Stumped], Runs briefly, then dies & won't restart Options

[ThinAir]

Background: In preparation for last year's RRC I fixed the mounting on the MPS of my son's stock 1971 914-4. All seemed well until we went out for the Saturday morning run - we turned a corner and the engine suddenly died and was clearly flooded. It restarted quickly, but we had the same problem several times on that trip after that.

I assumed that I had disturbed something electrical on the passenger side of the engine and in digging around I discovered that the wire connecting the Cylinder Head Temp Sensor was corroded at its base (in fact it fell off in my hands). Ok, this is simple I said - so I bought and installed a new CHT.

Current Problem: The engine will start, but runs for only about 30 seconds before it dies. At that point it will not restart, but it smells of fuel as if it is flooded. I've checked for spark and I have spark. I've disconnected, cleaned and reconnected every electrical connection on the engine & relay board that I can find - including every relay on the board. The only connections that I have not checked are the connector where the FI harness connects to the brain.

Does anyone have any ideas on what could cause this and where to look next?

[ThinAir]

Thank goodness for spare vehicles! A guy gave me a 74 carcass a couple of years ago with no engine or tranny... but it still had a MPS!

Swapped out the MPS and all the same behaviors are there so it's pretty clear that I have a wiring harness issue that is associated with the MPS, but the MPS is fine.

So now I have 2 choices for my son:
1. Trace down the broken wire and patch it
2. Get a Bowlsby FI wiring harness

I'm voting for #2!

[swl]

Thank goodness for spare vehicles! A guy gave me a 74 carcass a couple of years ago with no engine or tranny... but it still had a MPS!

Swapped out the MPS and all the same behaviors are there so it's pretty clear that I have a wiring harness issue that is associated with the MPS, but the MPS is fine.

So now I have 2 choices for my son:
1. Trace down the broken wire and patch it
2. Get a Bowlsby FI wiring harness

I'm voting for #2!

If you want to invest some time in #1 I have a set of multimeter readings that can give you a pretty good indication of the entire system. They are documented here http://www.914world.com/bbs2/index.php?showtopic=70441

[ThinAir]

If you want to invest some time in #1 I have a set of multimeter readings that can give you a pretty good indication of the entire system. They are documented here http://www.914world.com/bbs2/index.php?showtopic=70441

Thanks Steve! That looks very helpful. I hadn't looked at any wiring diagrams yet to see what connected to what so that I could test this kind of thing.