Need Advice with our experts.

Last week I flat bedded my 1974 914-4 to ArborMotion specialized Porsche Shop in Ann Arbor, MI for an oil change, general maintenance & running rough since it was not driven since 2018. I know this shop well and Sebastian the owner along with Porsche "Tyler Berry" Porsche Technician performed the work.

All (23) Pit Stop Inspections were perfect except the Rough Running Diagnosis (Ouch).
NOTE:
(I found the injection plug not plugged in all the way. The connector side had a little damage. I was able to repair. The car is running great at this time)

After getting it home It ran perfect and especially strong in 2nd gear to the sound off my Triad muffler.
The next day on a good engine warm up it started to miss-fire and running rough. Got home safely.
I discussed with Tyler at ArborMotion & Tyler wants me to ask if injector plugs typically have loose terminals and is there a fix solution?? This running issue is only on #2 cylinder & it worked perfect when fixed. Hoping Jeff Bowlsey can comment.

I have a question & wondering how 2.0 injectors run before going dead?? I know you have to take them out for a spray inspection, but it's not done yet. FYI: I don't think is bad grounds. Maybe in the injector plug??

Appreciate expert advice.

Tom

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Thee connections should be pretty snug. I remember them being fairly loose on my original and worn out FI harness. Nice and snug on the new harness from Jeff.
If when running rough you unplug the #2 connector and nothing changes, safe bet that's probably the one causing the issue. Check that the connector is providing signal to the injector, and if good, check the injector. Check plug wires, too.

BTW, I'd recommend replacing those clamps you have on the cloth lines on either side of your pressure gauge with FI hose clamps.

If the car has been sitting a long time it's possible the pintles are sticking.

I'd pull them and have them cleaned and tested.


While they are out, I'd echo using different fuel lines if you are running E10 and changing the type of clamps.

Tom, its hard to see any issue from the posted grainy photo , but if the terminals themselves have loosened their grip, its simple to remove them by releasing their tang, and 'tightening' their grip with a simple plier squeeze. They can loosen over time with relaxation of the steel terminal which function like springs to grip the terminals on the injectors, along with thermal cycling.

The best money spent will be on a new fi harness from Jeff Bowlsby with the later style “Amp” wire connector upgrade, instead of the original Bosch connectors

Not sure what you are describing?

Jeff,

My 914 has your wire harness that I purchased many years ago. Hardly any miles on it & always a garage queen with less than 4K miles since installed.
Wondering:
Can I get a new connector from you & have my Porsche Tech guy splice it on??

Hope to find out what 914sgofast2 is about??

Tom