Trouble shooting help sought

[GeezerTrainee]

I have an 84 GL 4WD wagon with about 65K miles that is showing some strange behavior. My wife drives it to work most days and she is having problems only on the return trip. Her commute is over a mountain pass (about 7000 ft). She has not had problems going over in the morning, but on the return trip in the evening, the car has lacked power after starting, and last night stalled.

 

The car is parked outdoors at home and at her workplace. It starts fine in both places. Both parking spots are level and the temperatures are about the same. The trip to work has about 2 miles of level road before it starts to climb. The return trip has an almost immeadiate climb. She has tried letting the car idle for a couple of minutes before starting the return trip, but it didn't seem to make any difference.

 

Things I've done since acquiring the car (not necessarily efforts to fix the problem) include checking the ignition timing & advance, valve clearances, choke operation, coolant condition and quantity, fuel, air and oil filter, belt and hose condition. I checked to see that the heat control valve on the air cleaner was working and it seems fine.

 

I haven't been able to recreate the problem when I've kept the car at home to work on it. The only variable I've been able to isolate is that the return trip has an immeadiate high engine load on a relatively cool engine. Is there something in the fuel/emission system that would cause a cool engine to not produce adequate power (and cause stalling)?

 

Thanks in advance for any suggestion

[nipper]

How about a tuneup to start off with. Get a good baseline, and a new T-stat.

 

Usually the problem is in reverse. Is her place of employment someplace where it gets damp, like in a valley?

 

nipper

[Skip]

this sounds like a fuel starvation issue

 

I believe this car has two fuel filters,

 

the one under the hood is called a vapor separator.

 

The other one is under the car by the fuel pump.

This one is the first

line of defense

(some call second due to the fuel pick up sock in the tank)

 

I'd try changing those as a first step.

[GeezerTrainee]

I've already done the following as a tune-up:

Checked all fluid levels

Checked battery connections and cables

Checked engine hoses

Checked and adjusted valve clearance

Cleaned and gapped plugs

Checked and adjusted ignition timing and vac advance

Checked and adjusted idle speed

Replaced air filter and checked PCV valve and filter

Replaced fuel filter (under hood) Will replace other

Checked EGR hoses

 

The engine temp (according to the guage) heats up to normal operating temperature in about 5 minutes. The heater puts out plenty of heat. The thermostat is the factory original (195F). It seems to be working based on change in temperature of the hoses leading to the heater core and radiator as the car is warmed up.

 

The car runs well, getting just under 30 mpg, starts great, has no problem rolling along at 70 mph for a couple of hours.

 

What has me baffled is the problem only seems to occur when trying to pull a fairly steep hill with a cold engine. I thought that there might be some water in the gas tank that was being moved with the change in angle. I dump in some dry-gas as well as change the secondary filter and see what happens.

[nipper]

What happens when pulling up a hill with a fairly warm engine?

 

Is the heat riser tube (from the exhaust to the intake snorkle) in one peice and connected?

 

 

nipper

[GeezerTrainee]

When pulling up a fairly steep hill with a warm engine, things seem fine. The heat riser tube is connect and intact. My wife allowed the car to idle until the rpm started climbing, then tapped the gas to drop the idle. After that, no problem. I'm going to take another look at the choke operation after letting the car sit for 8 hours.

[silverracerkh2005]

i don't know how to fix your prob, but where did you find an 84 with only 65k? lol

[Skip]

"Replaced fuel filter (under hood) Will replace other"

 

 

Think about which filter would suffer first.

If you decide to try this use some tool to pinch the line from the tank

as it will flow fuel when removed.

 

"The heat riser tube is connect and intact."

There also is a thermo valve in the snorkle that

opens to allow warm air into the air flow.

Does it open when cold?

[Frank B]

Any carbureted engine will run worse when cold. It's only when the engine properly warms up that everthing works as it should. You have a thermo valve that regulates the EGR and vacuum advance function when cold, you have the valve in the snorkle for the heat riser, the choke itself, the ASV if equiped. The 02 sensor needs to warm up, etc etc. With my Hatch, I let it warm up untill the guage reads about half way between stone cold and the normal operating temp before I pull away. But in your case, I would say to let it get up to normal temp before climbing that hill. It only takes a few minutes since it's an all aluminum engine.

[Cougar]

My money is on Skip's suggestion of the fuel filter. If that doesn't work then a new fuel pump may be in order.