Possible bad fuel pump, Don't think it's vapor lock...but??? Options

[Ampex351]

We took the car out for a ride today and she did fine until 40 minutes later. Just started acting like it was starving for gas then stopped running altogether.
Let it sit a few minutes thinking maybe vapor lock. Started and headed for home. Made it 2 miles and the same thing happened...just starving for fuel...then dies.
Now when I turn the key on there is no sound of the fuel pump. Usually make a little humming noise. This car had sat for nearly 8 years before I bought it. Possible bad fuel pump? What would you think?

Thanks

[SirAndy]

Vapor lock almost never happens while driving. The fuel needs to boil inside the pump and/or fuel lines for it to turn into vapor, which is hard to do if it is steadily flowing. Usually vapor lock will happen after you shut off the car and the heat soak does the boiling and the car will refuse to start until it has cooled off.
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[Johny Blackstain]

My only experience with vapor lock while driving was in bumper to bumper traffic during the summer- stop n go, stop n go. Never happened while moving normally. Never happens during winter in any kind of traffic.
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[SirAndy]

We took the car out for a ride today and she did fine until 40 minutes later. Just started acting like it was starving for gas then stopped running altogether.
Let it sit a few minutes thinking maybe vapor lock. Started and headed for home. Made it 2 miles and the same thing happened...just starving for fuel...then dies.
Now when I turn the key on there is no sound of the fuel pump. Usually make a little humming noise. This car had sat for nearly 8 years before I bought it. Possible bad fuel pump? What would you think?

Thanks

Could also be electrical. Is this stock FI? D-Jet? L-Jet? Carb conversion?

Is your relay board in good shape? Any cracks in the tar on the bottom side?
What about the relays on the board? Did you switch the fuel pump relay to a known to be good one? One of the headlight relays will do.
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[Ampex351]

We took the car out for a ride today and she did fine until 40 minutes later. Just started acting like it was starving for gas then stopped running altogether.
Let it sit a few minutes thinking maybe vapor lock. Started and headed for home. Made it 2 miles and the same thing happened...just starving for fuel...then dies.
Now when I turn the key on there is no sound of the fuel pump. Usually make a little humming noise. This car had sat for nearly 8 years before I bought it. Possible bad fuel pump? What would you think?

Thanks

Could also be electrical. Is this stock FI? D-Jet? L-Jet? Carb conversion?

Is your relay board in good shape? Any cracks in the tar on the bottom side?
What about the relays on the board? Did you switch the fuel pump relay to a known to be good one? One of the headlight relays will do.
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Stock '73 2.0 Is the relay board inside that metal housing box by the battery? Are the relays inside it? I haven't looked inside of the box yet. Rain coming for 2 days so will have to wait to do that. Is it possibly the fuel pump has gone bad after sitting for so many years?

[Rand]

The metal box by the battery is the ECU "brain." The relay board is opposite side. Usually a black plastic cover that pops off.

[Ampex351]

The metal box by the battery is the ECU "brain." The relay board is opposite side. Usually a black plastic cover that pops off.

OK...I know what you're talking about now. I'll check the relays and board (weather permitting). Thanks very much. You've been very helpful.

[JamesM]

Vapor lock almost never happens while driving. The fuel needs to boil inside the pump and/or fuel lines for it to turn into vapor, which is hard to do if it is steadily flowing. Usually vapor lock will happen after you shut off the car and the heat soak does the boiling and the car will refuse to start until it has cooled off.
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If you still have the pump in the rear, high altitude+hot day+gas containing ethanol I have found it to be much easier than I like to boil fuel in the pump/lines while driving.

Interestingly enough the crap that is sold as gas at most stations these days seems to be the largest contributing factor, at least in my case. Normally I try and always run ethanol free as its not to hard to come by around here however in cases where i cant get conveniently get it however times when i cant I almost always wind up getting bit by the issue if im driving high mountain passes.

Our engine bays get pretty hot, E10 doesn't do well with heat from a vaporization standpoint.
https://www.azom.com/article.aspx?ArticleID=17736


That being said, I have never experienced the issue on my cars that I have moved the pump under the tank, under any circumstances with either type of gas so...

[Frankvw]

It could also be vaccuumlock because tank is not vented well ? Or a clocked up/dirty fuelfilter ?

[rhodyguy]

A Haynes manual is very handy as a visual reference. Get one. Have the tank sock and fuel filter ever been serviced?

[rmital]

We took the car out for a ride today and she did fine until 40 minutes later. Just started acting like it was starving for gas then stopped running altogether.
…….

yes, check the fuel sock...and tank for that fact. maybe even fuel filter....
that would be good maintenance anyway after sitting for so long.

now what you think is staving for fuel?? back fire from running lean???

...or some bucking and stalling. that might be from running overly rich...not starving.
stock 2.0L
MPS and CHT suspect
Manifold Pressure sensor and Cylinder Head Temp sensor.
maybe why this car sat for 8 years. the MPS crapped out and the previous owner gave up.

If I was going to start anywhere, it would be with those 2 items. then report back.

[Ampex351]

We took the car out for a ride today and she did fine until 40 minutes later. Just started acting like it was starving for gas then stopped running altogether.
…….

yes, check the fuel sock...and tank for that fact. maybe even fuel filter....
that would be good maintenance anyway after sitting for so long.

now what you think is staving for fuel?? back fire from running lean???

...or some bucking and stalling. that might be from running overly rich...not staving.
stock 2.0L
MPS and CHT suspect
Manifold Pressure sensor and Cylinder Head Temp sensor.
maybe why this car sat for 8 years. the MPS crapped out and the previous owner gave up.

If I was going to start anywhere, it would be with those 2 items. then report back.

Very good points. Where is th manifold pressure sensor located? What the heck does it look like?

[SteveL]

I went down this same troubleshooting path - fuel pump, then fuel pump relay (1.8 L-Jet), then fuel filter and fuel sock, ...
Turned out to be a failing ignition coil. Food for thought if you have a spare around.

[rmital]

We took the car out for a ride today and she did fine until 40 minutes later. Just started acting like it was starving for gas then stopped running altogether.
…….

yes, check the fuel sock...and tank for that fact. maybe even fuel filter....
that would be good maintenance anyway after sitting for so long.

now what you think is staving for fuel?? back fire from running lean???

...or some bucking and stalling. that might be from running overly rich...not staving.
stock 2.0L
MPS and CHT suspect
Manifold Pressure sensor and Cylinder Head Temp sensor.
maybe why this car sat for 8 years. the MPS crapped out and the previous owner gave up.

If I was going to start anywhere, it would be with those 2 items. then report back.

Very good points. Where is th manifold pressure sensor located? What the heck does it look like?

since you're new to the 914, see if you have others in your area that you could meet up with; to do a quick introduction to basic stuff. where stuff is located...what's that...how does that look?? etc....might make a friend in the process....

or, just google like crazy and try to learn on your own

[porschetub]

Power the pump using 2 pieces of wire directly to the battery,if it runs then move on to all the issues mentioned in the replies.
Good luck.

[Valy]

Don't forget to check your fuel lines too. After many years in storage they may be dripping like a good irrigation system.