hello forum,
my symptom is while driving on highway i feel a momentary loss of power.
it is NOT cyclic, it is something that i can tell happens ever few minutes or seconds.
but it does.

the auto never dies, and in fact it drives very good. I am just afraid it might die and leave me stranded... (it has many times before but i hope i am past that)

any ideas, ever heard of anything like this?

thanx ahead

914 luva

74 FI stock 2.0

My 76 did that a few times on the highway just before it quit, turned out that the ground wire to the fuel pump was loose (fuel pump in the front trunk).

hi pvollma
thanks, its Saturday nights i will check this tomorrow. if i remember the wires to the fuel pump is not that great.
ktf

Your pump is most likely starving for power some don't deliver full pressure unless they receive a full 12volts or there abouts,others do ,I know Subaru pumps make full pressure at like 7 volts,check all your connections and make sure the filter is clean ,if you don't know that replace it.
Good luck.

Do the fuel filter & maybe the intake screen in the tank, clean the wiring connections...

^^^ I agree.
Start with easy stuff; loose wire, clean grounds.
Then fuel filters, inline and in tank.

Also check for loose plug wires and ignition coil connections.

Also check for a partly kinked gas hose bottom of the tank.

There's a hole, bottom of car above the steering rack, stick your hand in and feel the bigger fuel hose for a part kink.
With a part kink the pump will suck the kink closed every so often.

Most of the time it will do this at constant highway speed.

Just an update 1 month later
i have checked all the grounds -___ checked ok
I must check the fuel pump to make sure everything is ok there
i have to take out the plugs
I have checked the plug wires they all appear to be in order and nothing wrong.

there is still and issue.... I Will take the engine out this fall for sure
i dont want anything to happen next year this time.
i will have the engine inside all winter... (really looking forward to that)

anxious to find issue here.

Did you check the fuel filter and tank sock? And make sure the lines under the tank aren't kinked? Def sounds like fuel starvation to me. If your electrics are good and the pump is healthy, I'd bet there's something up in your fuel system.

Good luck!

Unplug the connector to the throttle position switch. Drive at and see if it goes away.

regarding driving on the highway and feeling a loss of power
but never dies.

I think i found it.

I had not changed the fuel filter in 3 years but then again in 3 years i had not put more than 500 miles on the car.

so I changed the fuel filter and could immediately tell that was the problem.
the auto ran a lot smoothier.
I have NOT got on the highway yet... I will tomorrow. then I will definately know for 100% sure. BUT I feel very confident.
there were no kinks in any of the fuel hoses.
however it is so crowded there with hoses and the fuel pump could use some new wires. THE Y connectors are just making it look so crowded there.

so stay tuned for a highway 60mph or more drive .

thank you all....
I really am so impressed at how much people can diagnose.
thanx again
KTF

If the tach instantly drops to zero, or zings up to the peg, you have a problem in the ignition points or points replacement. Or possibly in the tach.

--DD

Glad you're making progress! Short filter life is often due to rust / sludge in the gas tank. A dirty tank can also contribute to your lack of power, as the lines can't supply enough fuel when the engine needs it. You may want to take a peek inside your tank and see if it's corroded / full of sludge around the filter sock. Very common.

Just remove the 8mm bolts around the fuel filler neck and the bolt holding the expansion tank to the tank itself. When you remove the expansion tank you'll easily be able to look down with a flashlight and see the fuel sock. Just be really careful and don't use anything that could cause a spark. Also the perfect time to replace the filler and sender gaskets.

Good luck!

I was going to opine that it could be FI trigger points

well I just took it out on highway and seems ok... only 8 miles driven but went 70 mph no problem.. no hesitation or feeling like i had before.

while i am working on the fuel system i might as well check the gas tank.. but will do that tomorrow. bad rain storm just as I put teener in the garage.

thanx to all again.

Sounds like you found the issue. I had a similar issue that drove me crazy trying to chase it down. Double check every vent port on the expansion tank. For whatever reason all of them on mine were plugged and caused my fuel tank to go in negative pressure. This caused my fuel pump to play a game of tug of war with the fuel tank. It's worth checking while you're in there.