problems with SCT tuner
9/28/13, 07:21 PM
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problems with SCT tuner
so i just had problems with the car running rich and fouling the spark plugs.
i replaced the spark plugs and all is well. it was running richer than before though so i figured i'd re-enter the tune. its an SCT tuner and is running the HP tune. i dont know if something changed or what but now when started as soon as i hit the gas it dies, i can hear it sucking air too.
is it not getting fuel, or is the ratio off??
kinda lost here lol
i replaced the spark plugs and all is well. it was running richer than before though so i figured i'd re-enter the tune. its an SCT tuner and is running the HP tune. i dont know if something changed or what but now when started as soon as i hit the gas it dies, i can hear it sucking air too.
is it not getting fuel, or is the ratio off??
kinda lost here lol
9/28/13, 08:35 PM
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4.6L V8
running a procharger on 12psi
the HP tune has parameters i can change:
0-2000 spark is set at 0
2000-4000 spark is set at 0
4000-6000 spark is set at 0
air-fuel ratio is set at 4% more
axle ratio set at stock
top speed limit is off
then there is rev limiters etc
what should i set the spark and the air-fuel?? i think that may be the problem. because it starts up now, but as soon as you give it any gas it starts dying.
i know the air/fuel ratio needs to be around 13.5-14
running a procharger on 12psi
the HP tune has parameters i can change:
0-2000 spark is set at 0
2000-4000 spark is set at 0
4000-6000 spark is set at 0
air-fuel ratio is set at 4% more
axle ratio set at stock
top speed limit is off
then there is rev limiters etc
what should i set the spark and the air-fuel?? i think that may be the problem. because it starts up now, but as soon as you give it any gas it starts dying.
i know the air/fuel ratio needs to be around 13.5-14
9/29/13, 10:53 AM
#5
Legacy TMS Member
This was the tune provided for/with the supercharger?
Have you made any changes to the flow path ( different CAI or full exhaust, pulley change ) that might require an updated tune?
If your car hasn't seen any changes and is running poorly now then I'd start looking into other areas as Livin suggests. You might have a leak in the intake flow path ( sucking sound) upstream of the MAF which would lead to a lean condition as the mass air meter isn't reading the full volume of air.
If you can get the car to idle, hook up the SCT and use the data log function to take look and see what's going on. If you've got a lap top you can download SCT's data logging software and use that as part of your diagnosis.
The SCT will read all the stuff an OBDII reader will and you can see if any of those values fall outside of their proper range provided all of your sensors are working.
Also check to see if any diagnostic codes are present.
Doing this is going to provide you with a map so you can hopefully narrow down the issue which sounds like a mechanical one if the the car isn't throwing codes.
Have you made any changes to the flow path ( different CAI or full exhaust, pulley change ) that might require an updated tune?
If your car hasn't seen any changes and is running poorly now then I'd start looking into other areas as Livin suggests. You might have a leak in the intake flow path ( sucking sound) upstream of the MAF which would lead to a lean condition as the mass air meter isn't reading the full volume of air.
If you can get the car to idle, hook up the SCT and use the data log function to take look and see what's going on. If you've got a lap top you can download SCT's data logging software and use that as part of your diagnosis.
The SCT will read all the stuff an OBDII reader will and you can see if any of those values fall outside of their proper range provided all of your sensors are working.
Also check to see if any diagnostic codes are present.
Doing this is going to provide you with a map so you can hopefully narrow down the issue which sounds like a mechanical one if the the car isn't throwing codes.
9/29/13, 11:20 AM
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its what came with the car, and what i was told is on it. if thats what it was it shouldn't have done anything as far as the computer is concerned.
and no i hadn't changed anything and the car was running fine i just wanted to make sure, all i've done is replaced the spark plugs recently. everything was working and sounding fine. no codes.
i'm wondering if i need to set the spark degree? under the change values before you put the tune in? they are all set to 0.
and no i hadn't changed anything and the car was running fine i just wanted to make sure, all i've done is replaced the spark plugs recently. everything was working and sounding fine. no codes.
i'm wondering if i need to set the spark degree? under the change values before you put the tune in? they are all set to 0.
This was the tune provided for/with the supercharger?
Have you made any changes to the flow path ( different CAI or full exhaust, pulley change ) that might require an updated tune?
If your car hasn't seen any changes and is running poorly now then I'd start looking into other areas as Livin suggests. You might have a leak in the intake flow path ( sucking sound) upstream of the MAF which would lead to a lean condition as the mass air meter isn't reading the full volume of air.
If you can get the car to idle, hook up the SCT and use the data log function to take look and see what's going on. If you've got a lap top you can download SCT's data logging software and use that as part of your diagnosis.
The SCT will read all the stuff an OBDII reader will and you can see if any of those values fall outside of their proper range provided all of your sensors are working.
Also check to see if any diagnostic codes are present.
Doing this is going to provide you with a map so you can hopefully narrow down the issue which sounds like a mechanical one if the the car isn't throwing codes.
Have you made any changes to the flow path ( different CAI or full exhaust, pulley change ) that might require an updated tune?
If your car hasn't seen any changes and is running poorly now then I'd start looking into other areas as Livin suggests. You might have a leak in the intake flow path ( sucking sound) upstream of the MAF which would lead to a lean condition as the mass air meter isn't reading the full volume of air.
If you can get the car to idle, hook up the SCT and use the data log function to take look and see what's going on. If you've got a lap top you can download SCT's data logging software and use that as part of your diagnosis.
The SCT will read all the stuff an OBDII reader will and you can see if any of those values fall outside of their proper range provided all of your sensors are working.
Also check to see if any diagnostic codes are present.
Doing this is going to provide you with a map so you can hopefully narrow down the issue which sounds like a mechanical one if the the car isn't throwing codes.
9/29/13, 03:28 PM
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UPDATE: so having put the tune in and now its not running right and i can here it sucking air but dying as soon as you hit the gas.
i pulled the maf and cleaned it. nothing, same thing.
i unplugged the maf and it runs, but not correct.
so could this be the problem? its an sct maf.
could it be bad?
could it not be communicating right and i just need to have it tuned at a dyno shop?
i pulled the maf and cleaned it. nothing, same thing.
i unplugged the maf and it runs, but not correct.
so could this be the problem? its an sct maf.
could it be bad?
could it not be communicating right and i just need to have it tuned at a dyno shop?
This was the tune provided for/with the supercharger?
Have you made any changes to the flow path ( different CAI or full exhaust, pulley change ) that might require an updated tune?
If your car hasn't seen any changes and is running poorly now then I'd start looking into other areas as Livin suggests. You might have a leak in the intake flow path ( sucking sound) upstream of the MAF which would lead to a lean condition as the mass air meter isn't reading the full volume of air.
If you can get the car to idle, hook up the SCT and use the data log function to take look and see what's going on. If you've got a lap top you can download SCT's data logging software and use that as part of your diagnosis.
The SCT will read all the stuff an OBDII reader will and you can see if any of those values fall outside of their proper range provided all of your sensors are working.
Also check to see if any diagnostic codes are present.
Doing this is going to provide you with a map so you can hopefully narrow down the issue which sounds like a mechanical one if the the car isn't throwing codes.
Have you made any changes to the flow path ( different CAI or full exhaust, pulley change ) that might require an updated tune?
If your car hasn't seen any changes and is running poorly now then I'd start looking into other areas as Livin suggests. You might have a leak in the intake flow path ( sucking sound) upstream of the MAF which would lead to a lean condition as the mass air meter isn't reading the full volume of air.
If you can get the car to idle, hook up the SCT and use the data log function to take look and see what's going on. If you've got a lap top you can download SCT's data logging software and use that as part of your diagnosis.
The SCT will read all the stuff an OBDII reader will and you can see if any of those values fall outside of their proper range provided all of your sensors are working.
Also check to see if any diagnostic codes are present.
Doing this is going to provide you with a map so you can hopefully narrow down the issue which sounds like a mechanical one if the the car isn't throwing codes.
9/29/13, 04:07 PM
#8
Roush Forum Stalker
It doesn't sound like the tune is the problem. Sounds like your fuel is not getting where it needs to go in time or your fuel pump may be going. This was happening before you reloaded the tune, correct? So, it's definitely not the tune.
Good luck and let us know how you made out.
Good luck and let us know how you made out.
9/30/13, 08:41 AM
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well yes and no. because once i replaced the plugs it started right up and ran fine.
the mistake i made was re-loading the tune just in case. i should have left it alone lol
so now it'll start without the MAF plugged in, but once you plug it in it wont let you give it any gas. and it has pressure at the rail, i dont know how much but if i can give it gas without the maf plugged in i think it would be fine?
the mistake i made was re-loading the tune just in case. i should have left it alone lol
so now it'll start without the MAF plugged in, but once you plug it in it wont let you give it any gas. and it has pressure at the rail, i dont know how much but if i can give it gas without the maf plugged in i think it would be fine?
9/30/13, 01:02 PM
#10
Bullitt Member
If the sucking air sound you are hearing is pretty loud I would look for a vacuum leak. I would assume reloading the tune wouldve just reloaded it exactly as it was but I don't know a lot about tuning. Some of the bigger vacuum lines unhooked will keep it fron running
9/30/13, 02:30 PM
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no its the sound of the intake, minus the fact that its not firing.
i'm thinking when i disconnect the maf its allowing the car to run lean (more air) because its not getting enough gas.
when the maf is plugged in its not allowing the car to run because its reading too much air. so i'm starting to think fuel pump and regulator
i'm thinking when i disconnect the maf its allowing the car to run lean (more air) because its not getting enough gas.
when the maf is plugged in its not allowing the car to run because its reading too much air. so i'm starting to think fuel pump and regulator
9/30/13, 04:43 PM
#13
Roush Forum Stalker
Maybe it's a faulty MAF or faulty MAF sensors?
9/30/13, 06:28 PM
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yes the fuel sensor is connected and i think okay.
there is pressure at the fuel rail, so i know the pump is working i just dont know if its working correctly?
i know when i disconnect the MAF sensor it will let me give it gas, but it doesnt sense the air flow and wont give me any power and eventually it dies if i drive it.
i'm going to hook up the SCT tuner and run a datalog while its running if i can
there is pressure at the fuel rail, so i know the pump is working i just dont know if its working correctly?
i know when i disconnect the MAF sensor it will let me give it gas, but it doesnt sense the air flow and wont give me any power and eventually it dies if i drive it.
i'm going to hook up the SCT tuner and run a datalog while its running if i can
9/30/13, 06:30 PM
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also whether the fuel pressure sensor is plugged in or not it has the same problem. i unplugged it and it still wont give gas. maybe i should start by replacing that. idk
9/30/13, 10:23 PM
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i dont think so, because i just plugged everything in and started it.
it took gas for like one maybe two pumps then started dying when given gas.
also i can hear the fuel pump constantlly humming if you leave the key on. pretty sure its not supposed to do that?? maybe its working overtime??
it took gas for like one maybe two pumps then started dying when given gas.
also i can hear the fuel pump constantlly humming if you leave the key on. pretty sure its not supposed to do that?? maybe its working overtime??
10/1/13, 04:35 AM
#17
Legacy TMS Member
no its the sound of the intake, minus the fact that its not firing.
i'm thinking when i disconnect the maf its allowing the car to run lean (more air) because its not getting enough gas.
when the maf is plugged in its not allowing the car to run because its reading too much air. so i'm starting to think fuel pump and regulator
i'm thinking when i disconnect the maf its allowing the car to run lean (more air) because its not getting enough gas.
when the maf is plugged in its not allowing the car to run because its reading too much air. so i'm starting to think fuel pump and regulator
10/1/13, 08:08 AM
#18
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10/1/13, 09:01 PM
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so i datalogged the car
the fuel pressure reading at the rail (keep in mind its running rough right now)
is at a low of like 24 and high of 75
it seems to be sporadic. should it be holding steady?
maf volts are getting as high as 1.8 at idle
the fuel pressure reading at the rail (keep in mind its running rough right now)
is at a low of like 24 and high of 75
it seems to be sporadic. should it be holding steady?
maf volts are getting as high as 1.8 at idle
10/2/13, 09:31 AM
#20
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I couldn't find a voltage chart for the 4.6 3v MAF ( voltage x housing size = airflow put simply ) so I'm hesitant to say what 1.8 volts should equate to (seemed to me the range was 1-5 volts) but if the engine is idling steady and the MAF voltage is steady then the meter would appear to be working correctly. (that still doesn't account for any leaks past the MAF if they exist)
Yeah fuel pressure seems erratic, it should be holding steady at an idle (maybe 2 psi change as it idles) so that's where I would concentrate.
Before checking the fuel pump check the operation of the fuel pump driver then move onto the pump.
Also do you know if you have any sort of fuel system modifications like a voltage booster or different pumps?
Yeah fuel pressure seems erratic, it should be holding steady at an idle (maybe 2 psi change as it idles) so that's where I would concentrate.
Before checking the fuel pump check the operation of the fuel pump driver then move onto the pump.
Also do you know if you have any sort of fuel system modifications like a voltage booster or different pumps?