Sputtering low RPM when engine warms
08-20-2015, 11:00 PM
#14
Working on getting a volt reading on the injectors to test the resistance hopefully tomorrow. Will update and hopefully I can figure this problem out. This "legendary" problem I am find out that a lot of people have of these symptoms are usually not the same issue in the end. Seems like a lot of things could happen to cause the exact same issues and symptoms I guess, That would explain why there is no "real" answer to anything I suppose
08-23-2015, 06:36 PM
#15
3rd Gear Member
Join Date: Feb 2013
Location: PA
Posts: 556
Being you have replaced most sensors and fuel related components, you may just want to do a compression test a sticking valve or a broken valve spring can sometimes cause a stubble/hesitation without throwing a code.
However i have a couple of questions:
Does it occur at a specific RPM or specif range of RPM i.e. 1500 RPM or between
1500 and 1800 RPM range?
Is it repeatable, in other words can you get it to stubble/hesitate when holding the gas peddle at a certain position?
Also since you have a programmer do you have a tune it the car?
If so have you tried to return it to stock to see if it resolves the issue?
I know you just replaced the alternator but how is the battery, a battery with a bad or weak cell can cause all kinds of problems (DON'T run out and buy a battery, have that one tested by someone who knows how to to test it)
Next time don't run out and buy all those parts everyone of those sensor, fuel pump, filters and alternator can be tested even the temperature sensors can be tested.
Have you ever put any fuel injector cleaner in the tank, a clogged injector can also cause this without throwing a code. Again don't run out and buy injectors they can be tested. they can be balance tested or just visually inspected for spray patterns
I made a homemade tester is attached pics, I applied 35 PSI to the fuel rail sprayed each injector. I had a piece of paper 6" below the injector and compared the spray pattern and amount of fuel, i have pictures of the patterns if you want to see them but I figure at this point you just want you car fixed.
I'll wait for your response.
However i have a couple of questions:
Does it occur at a specific RPM or specif range of RPM i.e. 1500 RPM or between
1500 and 1800 RPM range?
Is it repeatable, in other words can you get it to stubble/hesitate when holding the gas peddle at a certain position?
Also since you have a programmer do you have a tune it the car?
If so have you tried to return it to stock to see if it resolves the issue?
I know you just replaced the alternator but how is the battery, a battery with a bad or weak cell can cause all kinds of problems (DON'T run out and buy a battery, have that one tested by someone who knows how to to test it)
Next time don't run out and buy all those parts everyone of those sensor, fuel pump, filters and alternator can be tested even the temperature sensors can be tested.
Have you ever put any fuel injector cleaner in the tank, a clogged injector can also cause this without throwing a code. Again don't run out and buy injectors they can be tested. they can be balance tested or just visually inspected for spray patterns
I made a homemade tester is attached pics, I applied 35 PSI to the fuel rail sprayed each injector. I had a piece of paper 6" below the injector and compared the spray pattern and amount of fuel, i have pictures of the patterns if you want to see them but I figure at this point you just want you car fixed.
I'll wait for your response.
08-25-2015, 11:52 PM
#16
Does it occur at a specific RPM or specif range of RPM i.e. 1500 RPM or between
1500 and 1800 RPM range? - The car does this in low RPM wouldn’t say between specific range but lower RPM, I can fluctuate the gas pedal and make it not sputter by giving it low gas and gradually come into the pedal after 3rd gear. At any time I push more than half way down on the pedal it will sputter or cut out.
Is it repeatable, in other words can you get it to stubble/hesitate when holding the gas peddle at a certain position? That all depends on how hard I get into the pedal it will go in and out but then eventually clear out once it gets up to speed. Idle is a smooth idle and revving the engine is smooth as well no hesitation. The certain position you speak of I could say it is pretty consistant with how hard I get into the pedal, cold start no problems could floor it and have good power, once warm always the same first 3 gears trying to get threw by babying the crap out of the gas to keep the sputtering to a minimum. Overdrive and going threw the gears manually help the RPMs raise and helps me get up to speed with the least sputtering.
Also since you have a programmer do you have a tune it the car?
There is no tune done to the car, just reading the info on the results
If so have you tried to return it to stock to see if it resolves the issue?
I know you just replaced the alternator but how is the battery, a battery with a bad or weak cell can cause all kinds of problems (DON'T run out and buy a battery, have that one tested by someone who knows how to to test it)
Had a battery in it and replaced it with the battery in my other Mustang had it tested first also and came back good. Had my wifes battery in the car when the alternator died to get it back home and still had the sputtering issue
Next time don't run out and buy all those parts everyone of those sensor, fuel pump, filters and alternator can be tested even the temperature sensors can be tested.
Yea I tend to jump the gun a lot when it comes to getting my Mustang back running smooth. To eager haha
Have you ever put any fuel injector cleaner in the tank, a clogged injector can also cause this without throwing a code. Again don't run out and buy injectors they can be tested. they can be balance tested or just visually inspected for spray patterns
Seafoam in tank and fuel injector clean from autozone as well. Seafoam threw intake as well
I made a homemade tester is attached pics, I applied 35 PSI to the fuel rail sprayed each injector. I had a piece of paper 6" below the injector and compared the spray pattern and amount of fuel, i have pictures of the patterns if you want to see them but I figure at this point you just want you car fixed.
I have tested the resistance on the fuel injectors and came back good havnt done the spray pattern though.
1500 and 1800 RPM range? - The car does this in low RPM wouldn’t say between specific range but lower RPM, I can fluctuate the gas pedal and make it not sputter by giving it low gas and gradually come into the pedal after 3rd gear. At any time I push more than half way down on the pedal it will sputter or cut out.
Is it repeatable, in other words can you get it to stubble/hesitate when holding the gas peddle at a certain position? That all depends on how hard I get into the pedal it will go in and out but then eventually clear out once it gets up to speed. Idle is a smooth idle and revving the engine is smooth as well no hesitation. The certain position you speak of I could say it is pretty consistant with how hard I get into the pedal, cold start no problems could floor it and have good power, once warm always the same first 3 gears trying to get threw by babying the crap out of the gas to keep the sputtering to a minimum. Overdrive and going threw the gears manually help the RPMs raise and helps me get up to speed with the least sputtering.
Also since you have a programmer do you have a tune it the car?
There is no tune done to the car, just reading the info on the results
If so have you tried to return it to stock to see if it resolves the issue?
I know you just replaced the alternator but how is the battery, a battery with a bad or weak cell can cause all kinds of problems (DON'T run out and buy a battery, have that one tested by someone who knows how to to test it)
Had a battery in it and replaced it with the battery in my other Mustang had it tested first also and came back good. Had my wifes battery in the car when the alternator died to get it back home and still had the sputtering issue
Next time don't run out and buy all those parts everyone of those sensor, fuel pump, filters and alternator can be tested even the temperature sensors can be tested.
Yea I tend to jump the gun a lot when it comes to getting my Mustang back running smooth. To eager haha
Have you ever put any fuel injector cleaner in the tank, a clogged injector can also cause this without throwing a code. Again don't run out and buy injectors they can be tested. they can be balance tested or just visually inspected for spray patterns
Seafoam in tank and fuel injector clean from autozone as well. Seafoam threw intake as well
I made a homemade tester is attached pics, I applied 35 PSI to the fuel rail sprayed each injector. I had a piece of paper 6" below the injector and compared the spray pattern and amount of fuel, i have pictures of the patterns if you want to see them but I figure at this point you just want you car fixed.
I have tested the resistance on the fuel injectors and came back good havnt done the spray pattern though.
08-30-2015, 07:52 AM
#20
3rd Gear Member
Join Date: Feb 2013
Location: PA
Posts: 556
Even though Ford did change to a non-return system in 1998 (some got it and some didn't, i have a 98 the still has the return system) they still have a fuel pressure regulator it is mounted right on the fuel rail.