2G AFPR-Hard Start

[Fcrz23]

Does an Adjustable Fuel Pressure Regulator cause Hard starting?

When it was a stock FPR it is one click start, then we install an AFPR it is now hard starting from a cold start
Thanks for the reply!!

 

[99dsmer4g63]

Did you adjust the fuel pressure to the correct pressure with the car running the vacuum line disconnected?

Make sure there is no leaks anywhere from the install. Is this a quality afpr or some $30 one from chinabay?

Do you have the fpr solenoid hooked up or straight from regular to vacuum source? If hooked straight from regulator to vacuum source is there any tees in the line?

-Daniel

 

[Fcrz23]

Did you adjust the fuel pressure to the correct pressure with the car running the vacuum line disconnected?

Make sure there is no leaks anywhere from the install. Is this a quality afpr or some $30 one from chinabay?

Do you have the fpr solenoid hooked up or straight from regular to vacuum source? If hooked straight from regulator to vacuum source is there any tees in the line?

-Daniel

Yup its a Quality AFPR and installed and adjusted properly. Same problem as the previous forum questions regarding hard starting in the site. Is it okay that an AFPR cause hard start?

Thanks for the reply will still double check then installation!!

 

[99dsmer4g63]

No I don’t think I would say it’s okay. I have a fuel lab on mine hooked directly to vacuum source set at the appropriate pressure. It starts as normal as it use to. Do you have ecm link? If so try priming the fuel pump for 5-10 seconds with the KOEO and then start the car. See if hard cold start is still present. If hard start is gone I’d say you have a small leak somewhere.

-Daniel

 

[Fcrz23]

Did you adjust the fuel pressure to the correct pressure with the car running the vacuum line disconnected?

Make sure there is no leaks anywhere from the install. Is this a quality afpr or some $30 one from chinabay?

Do you have the fpr solenoid hooked up or straight from regular to vacuum source? If hooked straight from regulator to vacuum source is there any tees in the line?

-Daniel

Yup its a Quality AFPR and installed and adjusted properly. Same problem as the previous forum questions regarding hard starting in the site. Is it okay that an AFPR cause hard start?

Thanks for the reply will still double check then installation

No I don’t think I would say it’s okay. I have a fuel lab on mine hooked directly to vacuum source set at the appropriate pressure. It starts as normal as it use to. Do you have ecm link? If so try priming the fuel pump for 5-10 seconds with the KOEO and then start the car. See if hard cold start is still present. If hard start is gone I’d say you have a small leak somewhere.

-Daniel

It is only hard start at a cold start, but once the engine starts, the next start is one click

Comparing an AFPR to a Stock FPR they start differently

 

[99dsmer4g63]

Do you have a way to turn the pump on before starting the engine while the engine is cold? I understand that it starts up fine after already running. But you also just pressurized the fuel system with it running. It could be such a small leak that you won’t see fuel on the ground.

Manually prime the fuel pump before starting the car while cold. See if the problem is still present.
Either use ecm link to enable the fuel pump before starting, use the fuel pump check connector if you have one or unplug the injectors and crank the motor for 10-15 seconds then plug the injectors back in. Do one of the above three things I said and report back after seeing whether the problem is still present or not.

Also it would be helpful if you filled out a vehicle profile for us.
1. Idk if you have ecm link to prime fuel pump.
2. Idk if you have fuel pump check connector because idk what year your car is.

I don’t have a profile filled out myself but I’m not asking people for help either.

-Daniel

 

[Fcrz23]

Do you have a way to turn the pump on before starting the engine while the engine is cold? I understand that it starts up fine after already running. But you also just pressurized the fuel system with it running. It could be such a small leak that you won’t see fuel on the ground.

Manually prime the fuel pump before starting the car while cold. See if the problem is still present.
Either use ecm link to enable the fuel pump before starting, use the fuel pump check connector if you have one or unplug the injectors and crank the motor for 10-15 seconds then plug the injectors back in. Do one of the above three things I said and report back after seeing whether the problem is still present or not.

Also it would be helpful if you filled out a vehicle profile for us.
1. Idk if you have ecm link to prime fuel pump.
2. Idk if you have fuel pump check connector because idk what year your car is.

I don’t have a profile filled out myself but I’m not asking people for help either.

-Daniel

The car is an all stock 2ga eclipse 1997 4g63t gst
Automatic Tranny converted to manual
Runs good and starts fine but at high rpm fuel cut happens

So we installed an AFPR, it solved the fuel cut problem but in exchange is the hard start at cold start
So we wonder if it is normal when you installed an AFPR

 

[CKOPOCT]

No, it is not normal. If the AFPR was properly installed and adjusted then there should be no issue with cold starts. It sounds like your cold start issue is due to a lack of fuel pressure at initial crank, likely being caused by a slight fuel leak allowing pressure to bleed off as the car sits. This is what @99dsmer4g63 is getting at.

To identify if this is the issue, pressurize the system before cranking while cold. If it fires right up, you have a fuel pressure bleed off problem (fuel leak). You could also install a fuel pressure gauge at the fuel rail (or anywhere) and monitor your pressure over time after the car is shut off to see if it gradually drops as the car sits.

 

[Fcrz23]

No, it is not normal. If the AFPR was properly installed and adjusted then there should be no issue with cold starts. It sounds like your cold start issue is due to a lack of fuel pressure at initial crank, likely being caused by a slight fuel leak allowing pressure to bleed off as the car sits. This is what @99dsmer4g63 is getting at.

To identify if this is the issue, pressurize the system before cranking while cold. If it fires right up, you have a fuel pressure bleed off problem (fuel leak). You could also install a fuel pressure gauge at the fuel rail (or anywhere) and monitor your pressure over time after the car is shut off to see if it gradually drops as the car sits.

Noted thanks for all of the advices really helps a lot!!

 

[99dsmer4g63]

At this point until you do one of three things I mentioned above to pressure the fuel system before cold start there isn’t anything else I can do to help you. No it’s not normal. Sounds like you have a leak.

Pressurize the fuel system on a cold start before starting the vehicle and report back with your findings. Until then there isn’t much left for me to say to help you. Help us help you.

Also a 97 year car should be a 2gb for future reference.

-Daniel

 

[pauleyman]

The car is an all stock 2ga eclipse 1997 4g63t gst
Automatic Tranny converted to manual
Runs good and starts fine but at high rpm fuel cut happens

So we installed an AFPR, it solved the fuel cut problem but in exchange is the hard start at cold start
So we wonder if it is normal when you installed an AFPR

Side note, you did not solve a fuel cut problem with this install. You may have solved a problem but it wasn't fuel cut. Possibly a fuel pressure issue at high rpm causing a misfire.
Fuel cut has nothing to do with fuel.

 

[FIBA M - EC17PSE]

when you shut the engine off what does the pressure gauge do? does it hold the pressure or drop real fast?

if it holds then its NOT the afpr. HOWEVER if it drops straight off then you either have a leak in the diaphragm or if its got a replaceable nozzle inside that could be leaking also.

when the AFPR does not hold pressure it means its harder to start up until the pressure is there, I know this as I had this problem also once. found my diaphragm to be leaking from a tear, once replaced it held pressure fine and thus cold starts were no longer a problem.

so you might need to open it all up and manually check if you are loosing pressure on the gauge after shut down

 

[chrisman287]

What brand regulator and was it new or used?

Cold start should not be an issue.