idle missfire??
- Thread starter gjp
- Start date
Peter
my Ty and me 25+ years
Re: idle missfire??
For what it's worth, I've noticed low voltage related idle issues. Sometimes the stereo amps at idle will draw down enough to cause a rough idle. Turn the radio off and the idle smoothed out. Or turn on the AC seemed to help.
So did the idle improve with the new battery?
Peter
For what it's worth, I've noticed low voltage related idle issues. Sometimes the stereo amps at idle will draw down enough to cause a rough idle. Turn the radio off and the idle smoothed out. Or turn on the AC seemed to help.
So did the idle improve with the new battery?
Peter
wantingasy
Active member
Re: idle missfire??
My idle improved after getting a new alternator and also after I had some wiring issues sorted out. Still kind of choppy sometimes though, but not as bad now.
My idle improved after getting a new alternator and also after I had some wiring issues sorted out. Still kind of choppy sometimes though, but not as bad now.
gjp
another post whore
Re: idle missfire??
I noticed last night the fuel pump changes sound when I turn on the headlights, parking light or even the radio. My voltages dont change much and I am still at 13.1 volts at lowest idle. Could be seeing less at the pump. The underdrive pulleys dont help much. Alternator is next on my list along with a new steering pump.(leaks)
I noticed last night the fuel pump changes sound when I turn on the headlights, parking light or even the radio. My voltages dont change much and I am still at 13.1 volts at lowest idle. Could be seeing less at the pump. The underdrive pulleys dont help much. Alternator is next on my list along with a new steering pump.(leaks)
QUICK STORM
B.A.M.F. BMW Tech
Re: idle missfire??
i'd also recommend the racetronix wiring harness
i'd also recommend the racetronix wiring harness
SY2455
70's Veteran
Re: idle missfire??
I'm still using the underdrive crank pulley with no problem, I just had to reinstalled the stock Alternator pulley because I couldn't raise the Idle rpm up to 900rpm like they say to do if you are using both pulleys. If I rasie the idle up at the throttle body after 15 min the computer would adjust the idle down to 650rpm.
gjp said:
I'm still using the underdrive crank pulley with no problem, I just had to reinstalled the stock Alternator pulley because I couldn't raise the Idle rpm up to 900rpm like they say to do if you are using both pulleys. If I rasie the idle up at the throttle body after 15 min the computer would adjust the idle down to 650rpm.
wantingasy
Active member
Re: idle missfire??
Where does datamaster/diacom read the voltages from? My laptop was reading like 14.0 while running (after my new alternator) but the starter was still clicking because it wasn't getting enough volts. ( my battery is in the back ) Check voltages at the ignition switch and at the solenoid. See if there's any drop. Mine was like 3 voltage drop!!!
Where does datamaster/diacom read the voltages from? My laptop was reading like 14.0 while running (after my new alternator) but the starter was still clicking because it wasn't getting enough volts. ( my battery is in the back ) Check voltages at the ignition switch and at the solenoid. See if there's any drop. Mine was like 3 voltage drop!!!
Re: idle missfire??
I'm having the saame trouble as you described. On cold startup it idles smooth and no problems. Once it gets warm or I start to drive it the hesitation gets worse. And when I turned on the headlights tonite I noticed the idle dropped. Did you fix the problem? And was it the vavle you mentioned? And what booster vavle are we talking about?
Thanks.
gjp said:
I'm having the saame trouble as you described. On cold startup it idles smooth and no problems. Once it gets warm or I start to drive it the hesitation gets worse. And when I turned on the headlights tonite I noticed the idle dropped. Did you fix the problem? And was it the vavle you mentioned? And what booster vavle are we talking about?
Thanks.
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B.A.M.F. BMW Tech
Re: idle missfire??
oh no, not the dreaded idle misfire thread!
oh no, not the dreaded idle misfire thread!
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B.A.M.F. BMW Tech
Re: idle missfire??
lets see if i can remember he replaced:
-replaced all vac. lines
-brake booster check valve (vac. leak)
-sent stock TB to have it bored out and a bushing to replace TB shaft leak(vac. leak)
-NGK UR5
-Taylor wires
-new cap and rotor
-ignition module
-fuel pump, walbro 255
-AFPR
-fuel filter
-MAP sensor (3bar)
-reseal intake manifolds w/ new gaskets
-alky injection
thats most of what i can remember of the top of my head
lets see if i can remember he replaced:
-replaced all vac. lines
-brake booster check valve (vac. leak)
-sent stock TB to have it bored out and a bushing to replace TB shaft leak(vac. leak)
-NGK UR5
-Taylor wires
-new cap and rotor
-ignition module
-fuel pump, walbro 255
-AFPR
-fuel filter
-MAP sensor (3bar)
-reseal intake manifolds w/ new gaskets
-alky injection
thats most of what i can remember of the top of my head
QUICK STORM
B.A.M.F. BMW Tech
Re: idle missfire??
he still has a rough idle but its not as bad, it might be a small crack in the head, IMO.
replace your vacuum lines, and follow the checklist.
he still has a rough idle but its not as bad, it might be a small crack in the head, IMO.
replace your vacuum lines, and follow the checklist.
QUICK STORM
B.A.M.F. BMW Tech
Re: idle missfire??
every owner goes thru this stuff, its part of owning a 15yr.old performance truck.
every owner goes thru this stuff, its part of owning a 15yr.old performance truck.
QUICK STORM
B.A.M.F. BMW Tech
Re: idle missfire??
reason being is you are getting lots of KR from vacuum leaks and ecm is pulling timing therefore results in a loss of power.
reason being is you are getting lots of KR from vacuum leaks and ecm is pulling timing therefore results in a loss of power.