Engine dies but restarts after 2 minutes, Help please! Only a couple weeks left to drive in MN Options

[SteveL]

74 1.8 with L-Jet. Starts and runs perfect for a while.
After driving or running for anywhere between 5-20 minutes, the engine loses all power, but still sounds like it is running for about 20 seconds, then dies completely. While it still sounds like it is running, I can put the pedal to the floor and it makes no difference. If I try to start it right away, it will not start. Every time so far, after I wait a couple of minutes it will restart and run like nothing happened for a few more minutes, then die again.
I have replaced the dual relay with a known good.
I think the next suspect is the fuel pump. I see a T fitting in the driver side fuel rail that is plugged by a bolt. Is that where I would connect a fuel pressure test gauge?
Is that the best next step to check?

[jcd914]

I think the next suspect is the fuel pump. I see a T fitting in the driver side fuel rail that is plugged by a bolt. Is that where I would connect a fuel pressure test gauge?
Is that the best next step to check?

Yes that is where you would hook up a fuel pressure gauge.

Suspecting the Fuel pump is a good next step.
You can also hook up a test light to the fuel pump circuit to see if the pump is getting power or not.

If I am remembering the L-jet system correctly, with the key on but engine off, pushing the flap open in the AFM should make the fuel pump run. You can check for power and pressure in a single test.

Jim

[dr914@autoatlanta.com]

excellent advice, the only other thing is if the flap is sticking it would die then the flap would unstick and one could just drive off, especially if it sort of runs like it is running out of gas, it would be sort of flooding out

I think the next suspect is the fuel pump. I see a T fitting in the driver side fuel rail that is plugged by a bolt. Is that where I would connect a fuel pressure test gauge?
Is that the best next step to check?

Yes that is where you would hook up a fuel pressure gauge.

Suspecting the Fuel pump is a good next step.
You can also hook up a test light to the fuel pump circuit to see if the pump is getting power or not.

If I am remembering the L-jet system correctly, with the key on but engine off, pushing the flap open in the AFM should make the fuel pump run. You can check for power and pressure in a single test.

Jim

[SteveL]

Yes that is where you would hook up a fuel pressure gauge.

Suspecting the Fuel pump is a good next step.
You can also hook up a test light to the fuel pump circuit to see if the pump is getting power or not.

If I am remembering the L-jet system correctly, with the key on but engine off, pushing the flap open in the AFM should make the fuel pump run. You can check for power and pressure in a single test.

Jim

I need to go buy a fuel pressure test gauge. That port on the fuel rail is tiny. I assume that I will need a special adapter. Any chance anyone knows what adapter is needed?

Thanks

[Mark Henry]

(IMG:style_emoticons/default/agree.gif) Check your fuel pressure.
I tape a pressure gauge to my back window, so I can see it out of my RV mirror and watch it for when the issue happens.
60 psi gauge (HF, etc), length of 5/16" FI hose, 2 FI clamps and yes the one injection rail has a test port. Don't lose the little screw, once the job is done I take it back off.

I had a 914 that would collapse the under tank large fuel hose and die after 20 minutes highway driving. Found and fixed it with a gauge reading.

[SteveL]

(IMG:style_emoticons/default/agree.gif) Check your fuel pressure.
I tape a pressure gauge to my back window, so I can see it out of my RV mirror and watch it for when the issue happens.
60 psi gauge (HF, etc), length of 5/16" FI hose, 2 FI clamps and yes the one injection rail has a test port. Don't lose the little screw, once the job is done I take it back off.

I had a 914 that would collapse the under tank large fuel hose and die after 20 minutes highway driving. Found and fixed it with a gauge reading.

Do I just clamp the 5/16" hose onto the fuel rail "T" stub? or do I get a connector that threads in where the little screw is?

Thanks

[jcd914]

(IMG:style_emoticons/default/agree.gif) Check your fuel pressure.
I tape a pressure gauge to my back window, so I can see it out of my RV mirror and watch it for when the issue happens.
60 psi gauge (HF, etc), length of 5/16" FI hose, 2 FI clamps and yes the one injection rail has a test port. Don't lose the little screw, once the job is done I take it back off.

I had a 914 that would collapse the under tank large fuel hose and die after 20 minutes highway driving. Found and fixed it with a gauge reading.

Do I just clamp the 5/16" hose onto the fuel rail "T" stub? or do I get a connector that threads in where the little screw is?

Thanks

Yes, you remove the screw and clamp the hose on the stub. Be sure to use quality FI hose and FI hose clamps.

Jim

[Triaddave]

KISS,
(keep it simple stupid) Is it a vapor lock issue? Relocate the fuel pump? The wife's car did the same thing, by the way, The water in the fuel doesn't burn off.

[porschetub]

excellent advice, the only other thing is if the flap is sticking it would die then the flap would unstick and one could just drive off, especially if it sort of runs like it is running out of gas, it would be sort of flooding out

I think the next suspect is the fuel pump. I see a T fitting in the driver side fuel rail that is plugged by a bolt. Is that where I would connect a fuel pressure test gauge?
Is that the best next step to check?

Yes that is where you would hook up a fuel pressure gauge.

Suspecting the Fuel pump is a good next step.
You can also hook up a test light to the fuel pump circuit to see if the pump is getting power or not.

If I am remembering the L-jet system correctly, with the key on but engine off, pushing the flap open in the AFM should make the fuel pump run. You can check for power and pressure in a single test.

Jim

(IMG:style_emoticons/default/agree.gif) with the George ,the flap can stick and leave you with no feedback to fuel requirement @ a given throttle position ,it needs to be free moving and snap closed quickly on the quadrant spring,posted recently about this and think the backfire story is a myth,mine has a vent disc and is sticking,the air flap is not a part easily bent,IMO its just wear as the air gate rubs on the lower cover plate when worn.
A guy on the bird has opened one up and proved that...good reading.
By all means check fuel pump function and check for a bad coil that is breaking down also.

[SteveL]

[/quote]
(IMG:style_emoticons/default/agree.gif) with the George ,the flap can stick and leave you with no feedback to fuel requirement @ a given throttle position ,it needs to be free moving and snap closed quickly on the quadrant spring,posted recently about this and think the backfire story is a myth,mine has a vent disc and is sticking,the air flap is not a part easily bent,IMO its just wear as the air gate rubs on the lower cover plate when worn.
A guy on the bird has opened one up and proved that...good reading.
By all means check fuel pump function and check for a bad coil that is breaking down also.
[/quote]

Thank you for the guidance, it is greatly appreciated. When it dies, I will be driving along at 1-2k rpm, so the flap would not be closed. And, even if the flap was closed, the car would still idle, correct?
I hadn't considered the coil. Do coils fail in an intermittent fashion like this? If so, I see RockAuto has an NGK coil for about $15, so easy to just replace in case (or do I need a Bosch blue coil at like $65?).
Thanks again.

[potomacmidget]

[quote name='SteveL' date='Oct 20 2019, 12:16 AM' post='2755838']
[/quote]
(IMG:style_emoticons/default/agree.gif) with the George ,the flap can stick and leave you with no feedback to fuel requirement @ a given throttle position ,it needs to be free moving and snap closed quickly on the quadrant spring,posted recently about this and think the backfire story is a myth,mine has a vent disc and is sticking,the air flap is not a part easily bent,IMO its just wear as the air gate rubs on the lower cover plate when worn.
A guy on the bird has opened one up and proved that...good reading.
By all means check fuel pump function and check for a bad coil that is breaking down also.
[/quote]

Thank you for the guidance, it is greatly appreciated. When it dies, I will be driving along at 1-2k rpm, so the flap would not be closed. And, even if the flap was closed, the car would still idle, correct?
I hadn't considered the coil. Do coils fail in an intermittent fashion like this? If so, I see RockAuto has an NGK coil for about $15, so easy to just replace in case (or do I need a Bosch blue coil at like $65?).
Thanks again.
[/quote]

Hi. I experienced a similar issue with my 71 D-JET. Installed new fuel filter, new blue coil , checked timing again (as I had physically pulled the distributor to work on it) and no resolution. Inspected my points and found gap/dwell way off. Gap had slipped and was almost nonexistent. Car would start, run great for 20 minutes and die. I think gap would completely close off with hot dizzy. I reset the points and checked dwell and my issue went away. Of course I should have started at the points....

[SteveL]

Hi. I experienced a similar issue with my 71 D-JET. Installed new fuel filter, new blue coil , checked timing again (as I had physically pulled the distributor to work on it) and no resolution. Inspected my points and found gap/dwell way off. Gap had slipped and was almost nonexistent. Car would start, run great for 20 minutes and die. I think gap would completely close off with hot dizzy. I reset the points and checked dwell and my issue went away. Of course I should have started at the points....

Running an Ignitor, been in there for, oh crap, 20 years? so it can't be the points.
Consensus seems to be: Hook up fuel pressure gauge to test port and watch it when it dies, replace coil, replace fuel filter.

[porschetub]

If the coil windings are failing it will generally break down after a period of running due to heat (resistance) ,not that common but it happens,buy a VW Bosch coil because they handle the heat from an aircooled motor,the Bosch ''blue" is a good choice and not expensive.
The reply is valid about points,I haven't used them for years however (IMG:style_emoticons/default/rolleyes.gif) .
Make sure have good plug leads ,as old ones can cause the issue you have also ,don't forget to check fuel supply also ,good luck

[SteveL]

Please educate me about ignition coils.
Did a couple of searches, and there seems to be multiple different part numbers for coils, even for Bosch coils, that are listed for our cars. I must admit that the electrical side is not my strong suit. Will any coil work if it is a certain ohm? What is the "right" coil?
Thanks