Unexpectedly dies after breaking to a stop

[Justwondering]

Back story:
The 87 fifth avenue hasn't been run in about a month.
I just finished the last cotter pin on the inner tierods, outer tierods, and idler arm.

Took about 12 times of pumping the pedal in sets of 3 and trying to start it.
Battery is fully charged. Seemed like it was just struggling to get gas from the tank up to the carb.
Once it did start, it did seem like it ran fine.
(Note, the gas pedal seemed like it was sitting much higher before the first push on it. After that, it was noticeable closer to the floor.)

Drove up to the gate (1/4 mile),
stopped
opened gate
pulled through and stopped
closed gate
drove out to highway and 3 miles down the road.
Stopped
changed drivers
drove back down the highway 3 miles
stopped at gate
opened gate
pulled through - engine died
started right up and pulled forward a bit farther
closed gate
drove 1/4 mile to house
turned off car.
Sat for about 30 to 40 seconds and tried starting the car and it started just fine.

Did not have the a/c on when driving.

Seemed like once the rpms got a little slower it died.

What do I look for?

 

[Mr C]

Was it on high idle or had you kicked it down...mine will stall sometimes stall if I drive off in high idle and then touch the gas after it has warmed up and the rpms drop off suddenly etc.

 

[Justwondering]

It was in high idle when we went through the gate.
It was NOT in high idle when we returned.

 

[Mr C]

That'll do it...things changed drastically (air fuel mixture) in the drop from high idle and things (ELB aka "Combustion Computer")couldn't compensate quick enough and it died. Start it up "hot" again and it was no doubt fine.

 

[Justwondering]

My concern is I'll be driving in traffic, stop at a stop sign, and have to put my foot on the gas at the same time as the my other foot on the brake to keep the engine running.
Or am I missing something?

 

[BudW]

Watch for a pattern of car dying.
If it dyes only after driving say 5 min after startup (or whatever it might be) only, or after driving 3 miles highway, or whatever it is before it dyes - then report back.

The occasional dying is somewhat normal but if we can find the pattern, then we are closer to a fix.
Random problems take a ton of time to find.

BudW

 

[Justwondering]

Will do.
It just felt so good to have it back in the mix again!

 

[Aspen500]

The bane of auto technicians everywhere,,,,,,,,,,,,the intermittent problem.

Doubt this is the problem but, how old is the fuel? It's at least 30 days old obviously. Gas now days, especially if it has any ethanol in it, starts to go bad in about a month with no stabilzer added to it.

 

[AJ/FormS]

If the stall is accompanied by a slightly rough running engine after the restart, I suspect a problem in the low-speed circuit, like a dirty air-bleed.
If the idle is still smooth, and it happens before the coolant is up to normal temperature, I would suspect a problem in the heat-riser cross-over,preventing the carb from warming up.
If the humidity is very high and the air temp. is below about 50*F, I might suspect icing.
That's all I got

 

[Justwondering]

Its going to the mechanic on Thursday to review my most recent work on the tierods.
Once I get the all clear, I'll put some stabilizer in it.

Apparently, the last time it was filled up was on a Sunday about a month ago. That means hubby put ethanol gas in it since the 1 station that sells good gas is closed on Sunday.

LOL

He's a handful of contradictions.

 

[89.Fifth]

Check for vacuum leaks. Stalling on braking is often because the vacuum break demand combined with a vacuum leak means the engine will stop pulling in fuel.

 

[lowbudget]

Check the carb to intake nuts. My Aspen did the die when die when stopping thing and that is what I traced it down to. As 89 Fifth said vacuum leak.

 

[AJ/FormS]

Check for vacuum leaks. Stalling on braking is often because the vacuum break demand combined with a vacuum leak means the engine will stop pulling in fuel.

This reminds me of something.
If you have a power brake booster;
With the engine idling,warmed up,OFF choke,and in park; push the brake pedal down and hold it down, for 5 seconds or so.The engine idle should not change speed nor quality.
Next,pump the brake pedal in rapid succession about 3 times, and again hold it down;the engine speed might fluctuate just a little, but almost immediately return to normal..
But if the engine idle speed drastically changes or it wants to stall, then it may be that the control valve inside the booster is broken, and the engine is able to draw atmospheric air through it, which, of course,to the engine,would behave like a giant vacuum leak.

 

[Justwondering]

An/form s. You are the winner.
Mechanic installed the Pittman arm for and checked everything. Told him my symptoms and he checked the vacuum lines and said it was the brake booster causing the problem. Once I get it home I'll follow the manual and your recent post to anchor this issue so I can diagnose it next time

Assuming my brain doesn't atrophy before then. Lol

 

[Justwondering]

So I can get a Napa brake booster with or without master cylinder and they also sell a brake booster check valve

How do I know which combination to get?

 

[BudW]

Brake booster is a repair you can perform, if you don’t mind laying on your back in front of the L/F seat, using normal hand tools. Not a comfortable job – but is doable.

If paying a repair shop, they “should” want 1.1 hours to do it.
I would guess 2½ hours for you.

It is faster if you don’t mess with the brake master cylinder, and just unbolt it front the brake booster, first (two nuts, with a bracket for cruise control cable).

The question is if you need a brake master cylinder, or not.

Tests from my ’77 FSM (should apply in your case).


I would check the flow charts, and if nothing indicates a problem with brake master cylinder, then I would avoid it.

The best test I know is when engine is running, hold down the brake petal. It shouldn’t slowly go to the floor. If it does, they this would be a great time to change while there.

BudW

 

[Justwondering]

What is a brake booster check valve?

 

[AJ/FormS]

The check-valve is a one-way valve. It is used to prevent the vacuum in the booster from returning to the intake manifold when you shut off the engine.
The valve is in the elbow where the vacuum line attaches to the booster.

 

[Justwondering]

thanks.

So this check valve for the vacuum line is like the check valve for the water system to the house.

Only difference, is the size and that the water system check valve is to make sure that the water going to the house doesn't flow back into the pressure tank.
I had to spend half a day yesterday replacing all three filters for the water system and putting in new ones -- regular maintenance that is now my responsibility. I was learning about different types of filters, molykote, pumps, check valves, pressure tanks -- my brain was on fire!

Somehow this is all starting to make sense... pretty freaky.

 

[Justwondering]

Car is home.
Parts are ordered.
Now to get Darth Car's antenna ready for testing . Bwhaaaa hhaaaaa haaaaa