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Discussion Starter #1
I am in the process of breaking in my rebuilt gearbox (along with shaking down the rest of the lengthy rebuild I've done over the last 4 years). The Verde has been driving very nicely for about 120 miles over the last few weeks. All varieties of driving as well. In-town errands, highway next-town runs, and higher-speed sweeping 2 lanes.

Today, I was out on the 2 lane route in 3rd at about 50 mph. The engine started losing spurts of power first, then really cut out as I slowed for a turn. It would idle without issue. Looking at the fuel pressure gauge under the hood indicated ~22psi at idle, which is pretty consistent with what I've seen over the life of the car. On throttle, I'd lose all power. I was able to limp 5 miles to a fuel station by accelerating at JUST off idle to get enough speed roll.

The tank took 6 gallons and I was able to drive the other 7 miles home without too much of an issue. I wasn't very heavy on the go pedal out of fear of losing power. Just before home, the symptoms returned. We're safely parked now.

So, to me, this feel a LOT like my fuel issues before I cleaned the tank and replaced all the filters/lines.

Things of note:

This is the first full tank since the tank cleaning. I had been putting ~5 gallons in at a time for the first 50 miles or so incase I had to pull the tank again. I think it's possible that the first tank fill knocked some previously untouched surface scale loose and I might just need to replace the filter.

I'm fairly sure the next step in diagnosis is simply pulling the fuel filter and inspecting it. I DO have an extra, so maybe I'll just put that on while I'm down there.

Any other ideas?
 

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But Mad North-Northwest
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I'd rule out air leaks before starting on the fuel system. A tear in the rubber intake hose would do that.
 

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Discussion Starter #3
I'll definitely check those. I do have a lot of confidence in them (all hoses silicon from Greg last year, NOS big air intake hose a few months ago), but maybe a clamp worked loose.

My gut (which is often wrong) thinks this is fuel related due to these factors:
  • 6 gallons of gas fixed the problem, at least temporarily. There was no cool down period or anything. Maybe a 5 minute stop.
  • Idle seemed very solid throughout this. Never a problem until it came off throttle. Don't those air leaks tend to show more at idle? I might be wrong about that.

Easy to check the hoses, though, so I'll be sure to do that while I'm in there.
 

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Fuel pressure seem really low. Should be around 37 psi at idle.
 

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But Mad North-Northwest
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Fuel pressure seem really low. Should be around 37 psi at idle.
With the regulator vacuum line disconnected it should be 36 psi. With the vacuum line hooked up it should be 36 psi minus engine vacuum, so it'll always be lower than 36 at idle.
 

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Discussion Starter #6
Small update. Didn't have a ton of time last night/this morning.

I started the car cold (no problem), warmed it up to ~200F and let it idle some more. Fan was on at this point. No issues. Idle is still rock solid across all temp ranges. ~22psi FP at idle with an immediate spike to ~36-37 at WOT.

It was suggested last time I had FP issues to unscrew the gas cap while the car was running to ensure no odd pressure situations in the tank. I'd like to get more info on this as it may seem pertinent. Especially since the car seemed to run better after filling up the tank more than halfway.
 

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Discussion Starter #7
I pulled the filter prior to the pump and there were juuuuuuuuuust enough crud in there to make me clean it and put it back on. Even if it doesn't ultimately solve my problem, the car is driving alright at the moment.

If I can replicate, I'll pull this filter again and ensure it is clean before removing it from the system.
 

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Does your fuel pump get the 12 volts it needs? 9 volts at the pump is not uncommon with factory wiring after several decades.
A full tank might hide a low fuel pump voltage due to gravity helping it push fuel.
 

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Discussion Starter #9
Does your fuel pump get the 12 volts it needs? 9 volts at the pump is not uncommon with factory wiring after several decades.
A full tank might hide a low fuel pump voltage due to gravity helping it push fuel.
I have not! I will do that next time I'm under there. Currently, the car is running well after the filter clean.
 
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