Hi all,

Back again with another strange one -

As of the last couple weeks, my 68 VE has been dying under high throttle.

Start, idle and just standard driving even up to fairly moderate throttle doesn't produce any issues.

However, under high or close to high throttle the car will run up (say from 20kmh to approaching 70kmh) without any issues (not hearing any knock/ping or other unusual noises) and suddenly cut out. No big fanfare at that point, engine stops firing, dash lights come on and I roll over to the curb doing my best impersonation of a chump.

At this point the car will take 5-10 min to start again - the most recent time I gave it about 5 mins between each attempt, the first just a small depression of the pedal before turning the key (no luck) and the second one pump right to the floor (wondering if it had starved instead of flooded) at which point it did start and drove right home. I think time was the factor there, though - upon stopping the fuel filter did have some fuel in it but wasn't completely full.

I've reproduced this on the road multiple times testing - flat,uphill downhill doesn't matter. I haven't been able to reproduce it sitting in the garage parked and probably won't since the neighbours may get cranky.

Does this happen to sound familiar to anyone? I've done a bit of poking around here and didn't find much close to the mark beyond flat spot on throttle threads.

Here's my list of attempted fixes so far:
Flushes/fluids/filters service on the car (trying to establish a baseline state)
Removal and clean of spark plugs (using a 6mth old set of NGK iridium plugs, just a wash in throttle body cleaner as sanding/scraping damages them. Plugs appear to be spot on for color etc and no buildup, none oiled)
Inspection and clean of points/rotor + timing (was out by about a degree...small potatoes)
Carby clean out (throttle body cleaner + toothbrush + revs)
New fuel pump (carter pump, not a dodgy one..seen too many people shy away from the sketchy ones here - did make idle and just about everything else much, much better, but still dies the same under WOT)

Other things possibly of note:
Carby 2bbl carby rebuilt about 3.5 years ago,
Ignition leads replace at about the same time,
Coil replaced (with bosch GT40) about same time,
Alternator reconditioned about 1 year ago,
Battery about 2 years old.
Points + rotor done about 3 yrs ago.
Ambient temperature for incidents ranged from about 25-40*C

Car pretty much weekend drives plus the odd 4hr trip. WOT has never been an issue up until this point - could go from street all the way to highway speeds and above under full throttle without issues for the previous 5 years of owning it.

Any ideas? If I've missed something not worth repeating feel free to just point me at the thread and I'll work my way through. Thanks for your time

Reminds me of when the fuel pickup filter sock collapsed in my van. Started off restricting speed and load. Restarts were tough. I pulled the fuel line off the pump, took the cap off the tank and blew it out. No problems after that.

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Joshua

My 64 Valiant had a tank fuel pickup line that was half blocked with rust / sediment , would run fine with a full tank, but at about 1/4 tank it must not have had enough head pressure to supply the pump, So it would quit running.

Cleaned the tube and have had no problems for the last ten plus years.

Also had similar problem with My 63 Val wagon it was clogged with gummy old gas residue , Ran great after cleaning pickup tube.

Az, Josh, thanks for the heads up - there doesn't seem to be any restriction on under performing on the car at all other than the aforementioned issue, but I'll still try blowing out the line from the pump to tank with compressed air.

I'll also check the other lines and filters just in case there's goop being picked up at high draw and causing blockages...not certain though as right upon stall there's still fuel in the filter right before the carby.

This issue also occurs full tank or down to a quarter (lots of testing been going on today)

Updating with some new behaviour from just now - will update original post.

Drove car for approx. 30 mins with no issues, just putting around at 20/25mph with zero issues.

Return trip took highway for giggles, drove at 60mph for approx 5mins, then about 50mph for about the same.

on the last stretch (doing 50mph) after about 5 mins on steady throttle (maintaining speed) All throttle response went - engine continued to run, but revs dropped to idle and no response from pedal.

Rolled it into the emergency lane where engine promptly died and jumped out to check - fuel in the filter, pushing back the arm on the carby squirted fuel in. Car didn't start again for about 30 mins, would turn but not kick over. Came home and immediately gave the pedal a good stab in neutral but problem didn't reproduce, seems to be only under heavy/consistently moderate to high load.

Did you test for spark when it wasn't working?

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

emsvitil, didn't check for spark - there a way to check quickly? I can take tools/gear out on the street in the boot and just reproduce the problem out the front of my house if need be

I had a similar "car suddenly dies but restarts later" issue. For me it was the orange box. Changed it out, problem solved. Any chance you have electronic ignition?

Emsvitil spark question is on the mark.

Brian

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https://tinyurl.com/yynpj4v2

Just wondering, would a ballast resistor do this? I mean would it get to hot to operate then cool down and work again?

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~Nic

You can either pull a ignition wire and see if a spark jumps or see if a timing light flashes......

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

No electronic ignition, just bog standard setup which has been freshened up with points and rotor.

Resistor has been recently replaced along with the alternator reco (<6mths)

I'll take it out for a spin in the morning and make it happen again, and take a timing light with me to throw on and see what happens - starting to feel like a spark problem, you're right. I'll come back with findings asap

Fuel lines seem okay, also cut open the fuel filter today and it was spotless but I'll still blow out the pickup line just in case.

Also talked to someone today who advised it may be caused by vacuum buildup in the tank from the breather line being blocked up and preventing fuel flow, spun it up with the filler cap off and the same thing still happened, also blew some air through the breather line and it's all free.

Thanks for your time and patience with this, by the way. Bit of a tricky one for me

I had almost the exact same symptoms in my '71 VW. Turned out to be the distributor base plate; it would pop out of its "home" just a few millimeters, which altered the timing just enough to cause it to not spark. then for no particular reason it would sometimes pop back down and run normally.

Changed the distributor and all was well.

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If it was easy, everybody would be doing it.

Fine rust in the fuel system caused similar symptoms in my '64. The particles would build up in the filter and periodically clog it, then drop off when the engine was shut down. The problem was eventually solved with a new fuel tank.

This is one place where a clear fuel filter could help with diagnosis.

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"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss

1964 Valiant V200, 225/Pushbutton 904
BBD, CAI, HEI, LBP, AC, AM/FM/USB, EIEIO

New points and rotor.....what about condenser? That can be a source of irratic behaviour till it fails completely.

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Sandy, coconuteater, haven't done condenser or looked too closely at the rest of the distributor yet - I'll try and reproduce the issue and throw a timing light on it today. If there's no spark I'll start with the distributor tinkering.

Will also attempt to blow out the fuel pickup line today.

slantvaliant, took off the current filter and chopped it open, seems completely spotless. Photos below





[/img]The little fuzzy bit on the filter is where I slipped with the hacksaw, and there might be the odd flake or two of plastic on it from cutting but otherwise looks good. Been on the car for about six months. Also tore the filter out and unrolled it - tiny bit of very fine junk in there but I don't think it'd be enough to make trouble (last photo)

Thanks for the pointers all[/img]