Add me to the list of bucking, hesitation, now no start

[Kblack1101]

Just wanted to throw some of my recent experiences in the thread for you.

I have been chasing bucking / loss of power / hiccups (like a carb) / no start for a while now.

This started with Previous owner issues - faulty petronix not firing cyl. #3

Start simple / obvious and go from there.
1. Correct distributor and timing (points / dwell set correct, condenser new)
2. Good coil (wired correct and tested to be good) \
3. Check fo vacuum leaks
4. Replaced ECU - NA to you -your vehicle is running
5. This is where it gets interesting. I will spare you all the issues / details but the symptoms ended up being the fuel pressure regulator. Bus was hard starting and would idle great, then stall. I was able to keep it running using starting fluid squirt through the air box.

After replacing the fuel filter and pump, my bus started and drove. Ran great at idle. BUT Once I tried to use the powerband above an estimated 2k RPM, I experienced hesitation, flat throttle, no power. The fuel pressure regulator was intermittently causing my fuel pressure to drop by allowing too much gas to flow back into the tank.

Check your fuel pressure. Cycle the pump and see if the circuit holds pressure when the pump isn't running. Put a fuel / brake line hose clamp ahead of the FPR and try again. Does it hold pressure now?

Another symptom I experienced was that my gas cap was locked on pretty hard - I'm guessing not because it was being sucked in (no vent) but because the pressure outward was so great.

Good luck. You will get it!

[ivwshane]

[SGKent]

[Kblack1101]

@ivwshane - did you ever figure this out?

After sitting 4 days in the driveway, I fired up the bus and drove it to the store yesterday. Bucking / kicking on the way there (but idling and running real nice) -
Before leaving the store, I pulled my gas cap and immediately smelled fumes.

Waited a good 30-45 sec. replaced cap and the Bus fired up and drove fine the entire way home. Smooth acceleration through all gears.

My first thought is that my venting system is not functioning properly. Bus sat all week, fuel expansion / contraction / evap built up and didnt vent...

What would cause this? Bad evap canister?

Anyone have any inputs?

[ivwshane]

That’s really interesting because I may have replaced the gas cap before this all happened (as a preventative measure for the smogg check). My gas cap is extremely tight too.

Unless I have the evap hoses hooked up incorrectly, they are all new with new clamps.

I haven’t looked at the bus since posting though…
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77 westy 2.0 FI
69 ghia coup 1600dp
70 single cab