Leaning Out At Low Rpm Problem ...and Some Other Stuff
03-25-2009, 11:48 AM
#11
Senior Member
Thread Starter
Join Date: Aug 2006
Location: Croatia
Posts: 636
Likes: 0
Received 0 Likes
on
0 Posts
Vehicle: 1999 Hyundai Tiburon
No need to get offended. Unfortunatelly no Harbor Freight overhere will have to try to get a vacuum leak tester anyway. From States probably.
I will check TPS and RPM calibration and redo that part and see if it helps. Thank you guys.Will keep you posted of what is going on with this issue.
Ok I found three from a shop that delivers to Croatia. WHich one would you recomend?
KAL
ACTRON
No Name?
I will check TPS and RPM calibration and redo that part and see if it helps. Thank you guys.Will keep you posted of what is going on with this issue.
Ok I found three from a shop that delivers to Croatia. WHich one would you recomend?
KAL
ACTRON
No Name?
03-25-2009, 12:33 PM
#12
Senior Member
Join Date: Mar 2006
Posts: 5,754
Likes: 0
Received 0 Likes
on
0 Posts
Vehicle: 1997 Tiburon
Just to let you know, you can also make a vacuum tester or a pressurized turbo leak tester. Google it, there are ton's of DIY's. The DSM forums have like 3-4 different kinds lol.
03-25-2009, 07:49 PM
#14
Senior Member
Join Date: Feb 2009
Location: Boston
Posts: 1,932
Likes: 0
Received 0 Likes
on
0 Posts
Vehicle: 2006 Pontiac GTO
Fuel pressure should be close to the stock 44psi (with the vac line disconnected, i.e. N/A WOT) assuming you use the FIC to rescale the injector duty cycle according to the new injector sizes.
You mentioned you sometimes lose fuel pressure. That should NEVER happen regardless of what's going on with the FIC and/or ECU. You also mentioned that the fuel pressure went down when you changed to larger injectors?! Something sounds wrong there.. I would investigate that first..
I would get an OBD2 reader so you can read the ECU fuel trims, that will help with figuring out what's going on.
Regarding the riching out after idling for a while - that can only be an closed-loop/O2 sensor related issue. The O2 map should not modify anything in that psi range. What is your O2 setup and wiring like? Do you have a second O2 sensor after a cat? As far as I read, not only the 1st sensor influences trims but 2nd O2 sensor can also sometimes make the ECU change trims in an attempt to optimize emissions..
The whole thing you are describing can be an O2 sensor issue, it seems that as soon as you go out of closed-loop (throttle pressed more than a certain amount) the problem goes away..
You mentioned you sometimes lose fuel pressure. That should NEVER happen regardless of what's going on with the FIC and/or ECU. You also mentioned that the fuel pressure went down when you changed to larger injectors?! Something sounds wrong there.. I would investigate that first..
I would get an OBD2 reader so you can read the ECU fuel trims, that will help with figuring out what's going on.
Regarding the riching out after idling for a while - that can only be an closed-loop/O2 sensor related issue. The O2 map should not modify anything in that psi range. What is your O2 setup and wiring like? Do you have a second O2 sensor after a cat? As far as I read, not only the 1st sensor influences trims but 2nd O2 sensor can also sometimes make the ECU change trims in an attempt to optimize emissions..
The whole thing you are describing can be an O2 sensor issue, it seems that as soon as you go out of closed-loop (throttle pressed more than a certain amount) the problem goes away..
03-26-2009, 04:57 AM
#15
Senior Member
Thread Starter
Join Date: Aug 2006
Location: Croatia
Posts: 636
Likes: 0
Received 0 Likes
on
0 Posts
Vehicle: 1999 Hyundai Tiburon
OK I'll go in order of replies fing02.gif :
2 tanc: Well it doesn't get funnier than that laugh.gif . No matter how much I do use Internet, even in my line of work, it seems that it is always easiest to forget and search for a more simple and at hand solutions to resolve problems. Great advice I will most certainly find that out. fing02.gif
2 Socks: Yeah I got it, reading seems to be ok.
2 radu_rd2: Well I do have and OBD II reader but since european spec tibs do not conform fully to the OBD standards (our cars are neither OBD I or OBD II but rather Hyundai OBD 1.5 spec laugh.gif ) the info from the ECU can be read only with a Hyundai Hi-Scan reader which, of course, does not show fuel trims. For riching out in idle I was suspecting of O2 sensor being the problem but the O2 map isn't changing anything in that range just injectors scaled by the FIC. So either FIC is not scaling down the injectors properly or something else is causing this (injectors are ckecked and fine)
As for O2 setup I have only one O2 sensor and the wiring is done with a resistor as FIC manual suggests. Thing is that we have tried to unhook the O2 sensor and mapped the car without it (that was the setup when I had Unichip and it did not caused any problems) and the problems were still there. As for the fuel pressure I checked again my FP is currently set at 3 bars (which is around 44 psi). What bothers me is that currently I do not have any problems when the AC is off but as soon as I start the AC car starts bogging and leaning out. That should not have any connections to the fuel pressure. Or should it ? We have ckecked the fuel pump (Walbro 255 lph) and it works fine and gives the correct pressure. FPR seems to be ok also. So I am a bit buffled by the situation. Just to point out, if I leave the AC off I can drive without any problems (well except RPM's jumping up and down if I press the clutch suddenly) in off-boost or boosting.
Another thing is that RPM jumping game when I press the clutch suddenlly. If I understood correctly this corelates to the large injectors being scaled down. WOuld it helped if I scale down injectors 60 or 62% instead of 64%?
2 Socks: Forgot to put my reading in in/hg at idle smile.gif It is 0,7 on a bar gauge but comparing it to the psi gauge it is around 20 in/hg
2 tanc: Well it doesn't get funnier than that laugh.gif . No matter how much I do use Internet, even in my line of work, it seems that it is always easiest to forget and search for a more simple and at hand solutions to resolve problems. Great advice I will most certainly find that out. fing02.gif
2 Socks: Yeah I got it, reading seems to be ok.
2 radu_rd2: Well I do have and OBD II reader but since european spec tibs do not conform fully to the OBD standards (our cars are neither OBD I or OBD II but rather Hyundai OBD 1.5 spec laugh.gif ) the info from the ECU can be read only with a Hyundai Hi-Scan reader which, of course, does not show fuel trims. For riching out in idle I was suspecting of O2 sensor being the problem but the O2 map isn't changing anything in that range just injectors scaled by the FIC. So either FIC is not scaling down the injectors properly or something else is causing this (injectors are ckecked and fine)
As for O2 setup I have only one O2 sensor and the wiring is done with a resistor as FIC manual suggests. Thing is that we have tried to unhook the O2 sensor and mapped the car without it (that was the setup when I had Unichip and it did not caused any problems) and the problems were still there. As for the fuel pressure I checked again my FP is currently set at 3 bars (which is around 44 psi). What bothers me is that currently I do not have any problems when the AC is off but as soon as I start the AC car starts bogging and leaning out. That should not have any connections to the fuel pressure. Or should it ? We have ckecked the fuel pump (Walbro 255 lph) and it works fine and gives the correct pressure. FPR seems to be ok also. So I am a bit buffled by the situation. Just to point out, if I leave the AC off I can drive without any problems (well except RPM's jumping up and down if I press the clutch suddenly) in off-boost or boosting.
Another thing is that RPM jumping game when I press the clutch suddenlly. If I understood correctly this corelates to the large injectors being scaled down. WOuld it helped if I scale down injectors 60 or 62% instead of 64%?
2 Socks: Forgot to put my reading in in/hg at idle smile.gif It is 0,7 on a bar gauge but comparing it to the psi gauge it is around 20 in/hg
03-26-2009, 06:12 AM
#16
Senior Member
Join Date: Feb 2009
Location: Boston
Posts: 1,932
Likes: 0
Received 0 Likes
on
0 Posts
Vehicle: 2006 Pontiac GTO
It is really weird that the A/C affects anything.. how is your IAC set up? I would try removing it by plugging the hole in the manifold, and opening the TB a little bit. If the problems go away that might be the issue..
I doubt using larger injectors and scaling down should affect anything, I have 440ccs scaled down and working fine..
QUOTE (Hive @ Mar 26 2009, 06:57 AM)
Another thing is that RPM jumping game when I press the clutch suddenlly. If I understood correctly this corelates to the large injectors being scaled down.
I doubt using larger injectors and scaling down should affect anything, I have 440ccs scaled down and working fine..
03-26-2009, 08:30 AM
#19
Senior Member
Thread Starter
Join Date: Aug 2006
Location: Croatia
Posts: 636
Likes: 0
Received 0 Likes
on
0 Posts
Vehicle: 1999 Hyundai Tiburon
QUOTE (Hive @ Mar 26 2009, 01:57 PM)
2 Socks: Forgot to put my reading in in/hg at idle smile.gif It is 0,7 on a bar gauge but comparing it to the psi gauge it is around 20 in/hg
it was in my previous post
03-26-2009, 12:07 PM
#20
Senior Member
Join Date: May 2006
Posts: 4,722
Likes: 0
Received 0 Likes
on
0 Posts
Vehicle: 2001 Hyundai Tiburon
Start simple and work my way back from there, didn't see it anywhere in the post I don't think.
Aftermarket fuel pump? What size?
What you using to regulate fuel pressure? Just a regular FPR or you using a rising rate one?
Aftermarket fuel pump? What size?
What you using to regulate fuel pressure? Just a regular FPR or you using a rising rate one?