LH2.2 intermitant fail, maybe tps related?
 

1982 US 928S 5 spd, Euro hybrid motor, US 85 wiring harness, LH, and EZK brains. Some issues with the throttle position switch last week, but running fine since then until today during dyno runs the fuel injection seemed to just cut out completely. releasing the accelerator seemed to reset the problem, but despite a fair amount of looking no problems found.

Fuel pressure 50+., relays all checked out, battery connections cleaned, throttle switch replaced, wires wiggled. Nothing seemed to fix it except unplugging the throttle position switch.

I'm not "sure" its exactly in sequence, but we took a break from the fuel injection issues and replaced all the bad light bulbs around the car including a new relay for headlights (raised up, didn't turn on before relay).

Now we can't seem to make the fuel injection glitch reappear.

Monday the testing continues, any thoughts?

If throttle switch acts as though it is closed, and revs are above about 2000rpm, then fuel injectors are cut off..........

Thanks John. ;)

That fits what is occurring very well.

Well, a few years ago I apparently developed a problem with the connection to my '85's timing and reference sensor. Under acceleration, occasionally the car would try to launch me through the windshield. The engine would cut out for about a second or so, and it felt like the car was trying to launch me out the windshield! This only happened for a second, and only on very rare occasion. I checked everything, and eventually was able to get the car to miss by running it without the air filter/ MAF assembly and jiggling the T&R signal. I discovered a large vacuum leak at the same time!

Take a carefull look at the connector for your T&R sensor. If it is bad...you're going to be thrown toward your windshield.

N!

Normy, What did you have to do after it cut out to make it go again?

On this car the accelerator had to be returned to the idle position for the engine to fire again.

A new wiring harness from Porsche arrived yesterday, and it has a new flywheel sensor and throttle switch already.