Inertia-related FI running problems - your diagnoses wanted.

[Matt Brannon - Midwest Bayless]

Hi folks,

Occasionally I have run across FI Xs that start and run perfectly fine, but for reasons mysterious, will stop running intermittantly when moving from a stop. If you've had this happen, you know exactly what I'm talking about; - 10 feet into the intersection it conks out, pissed off drivers honking behind you, after a few seconds of frantic cranking the car starts again and off you go.

There are several potential culprits to this problem, I would like to get a thread going for owners who have fought and won this battle to share your findings.

I have seen it occur from:

- Bad ignition switch
- Bad connector at AFM
- Bad AFM
- Bad fuel pump connections
- Bad multi-relay
- Bad fuel pressure regulator
- Cracked air snorkel + bad dogbone = Big air leak
- Others?
- Broken wire inside of FI harness

This last one of problems inside the wiring harness seems to be the most vexing. Anyone who has had success in tracking this one down, please post your findings.

-Matt
www.midwest-x19.com


-Matt

 

[DougESmith]

Never had it happen, but

Is the tank full?
Does it happen on upshift?
Could it be silt in the tank?
Is the pickup lines "sock" collapsing?

 

[Dallarax19]

I will speak for Brad Garska on this one, he spoke of problem he had where condensation traveled down the wire harness to the ECU and on hard turns it would short it out and the car would sputter. I believe he found drops of water traveling back and forth in the ECU case during operation. Kudos to him for finding it. I don't recall the fix but the issue is certainly plausible.

 

[jake]

Loss of connection at temp sensor on thermostat housing will create an instant flood condition. water seems to collect in the connector also. it will cause it to die abruptly at low speeds. at freeway speeds usally sudden loss of power or intermitten backfires if starting to loose connection randomly.

 

[Carl_Auer]

Have not had this with my FI but

It would happen with my old Orange Crush 78X. Steve Ambrose and I fought with this for about three weeks. Fuel lines, fuel pump, carb, everything. He would say "Your good to go!" I would hop in, start driving, come to a stop light, idle fine, light would turn green, go 10 feet and it would die. Finally, after trying everything, we pulled the fuel tank pickup/sender and the sock filter looked like it was coated in varnish. Cut that off, and not one problem with stalling after that. I have not looked at the fuel pickup for my 82, but I imagine it also has a sock filter on the tank pickup end, and that could also be a cause...