HOT STAR ISSUES, LOOKING FOR REAL SOLUTIONS.

Specific conversations and info for the BMW E28 M5 and M535i.
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M6Zealot
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Joined: May 27, 2010 7:57 PM

HOT STAR ISSUES, LOOKING FOR REAL SOLUTIONS.

Post by M6Zealot »

I am sure more than one of you have had an HOT START ISSUE with you M5 S-38 motor. For me its been a hit or miss issue for years.

Please I seeking real solutions not speculations. I need to see if anyone here has had this issue and was able to fix it with no more issues.

Just about everything has been replaced during my restoration 4 yrs ago. All the stuff that matters that can relate to a hot start issue
Crank Sensors
fuel injuectors
Plugs/ wires and cap & rotor
Fuel pump Both, relays
Thremo time switch
New fuel filter/ fuel lines/ Pressure regulator
Ignition coil/ plug wires.
starter/ new battery

Not replaced was the fuel injection ressure sensor not sure if they go bad?

Is there something I am over looking? Please any help would be great

BMWMotorsports1@aol.com

Thats my Email
C.R. Krieger
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Re: HOT STAR ISSUES, LOOKING FOR REAL SOLUTIONS.

Post by C.R. Krieger »

M6Zealot wrote:Please I seeking real solutions not speculations. I need to see if anyone here has had this issue and was able to fix it with no more issues.
:roll: Are you serious? Do you really think anyone here can definitely diagnose and solve your problem the first time without fail?
alijonny
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Post by alijonny »

what's her name and what is she doing (or not doing)? Is she someone we would know from TV? Movies? Radio?

I'm just going by the title, BTW.
mooseheadm5
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Re: HOT STAR ISSUES, LOOKING FOR REAL SOLUTIONS.

Post by mooseheadm5 »

M6Zealot wrote:Not replaced was the fuel injection ressure sensor not sure if they go bad?
What pressure sensor would that be?

What testing have you done to check your hot start problem? A residual fuel pressure test would be a good first step. If the fuel pressure is good, you will want to check to see if you have spark and injection pulse when there is a no start issue.
1st 5er
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Post by 1st 5er »

This might help... http://www.mye28.com/viewtopic.php?p=86 ... a0a#869180

We chased one here for a few months, turned out to be a bad temp switch (the blue one).
slimdevil27
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Post by slimdevil27 »

Is it a crank no start? No crank? Does it sputter like it's trying to start but won't?

I, SLIMDEVIL, HAVE CONCLUSIVELY DIVINED THE ISSUE!!

IT IS...THE NUT BEHIND THE WHEEL.
Mark 88/M5 Houston
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Re: HOT STAR ISSUES, LOOKING FOR REAL SOLUTIONS.

Post by Mark 88/M5 Houston »

mooseheadm5 wrote:
M6Zealot wrote:Not replaced was the fuel injection ressure sensor not sure if they go bad?
What pressure sensor would that be?

What testing have you done to check your hot start problem? A residual fuel pressure test would be a good first step. If the fuel pressure is good, you will want to check to see if you have spark and injection pulse when there is a no start issue.
I think he may be talking about the Barometric Pressure Sensor.
mooseheadm5
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Re: HOT STAR ISSUES, LOOKING FOR REAL SOLUTIONS.

Post by mooseheadm5 »

Mark 88/M5 Houston wrote:
mooseheadm5 wrote:
M6Zealot wrote:Not replaced was the fuel injection ressure sensor not sure if they go bad?
What pressure sensor would that be?
I think he may be talking about the Barometric Pressure Sensor.
Unplug that to rule it out.
Rich Euro M5
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Post by Rich Euro M5 »

I don't see the coolant temp sensor listed. This can cause hot start issues if the resistance is out of specification (reads higher resistance than it should for any given coolant temperature).
1st 5er
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Post by 1st 5er »

Rich Euro M5 wrote:I don't see the coolant temp sensor listed. This can cause hot start issues if the resistance is out of specification (reads higher resistance than it should for any given coolant temperature).
1st 5er wrote: We chased one here for a few months, turned out to be a bad temp switch (the blue one).
Brent in NZ Hartge 535i
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Post by Brent in NZ Hartge 535i »

when it doesn't start is there spark at the spark plugs??
if not maybe check for dry solder joints in the ecu common fault.
if it has spark then start looking at fuel issues.
you dont need the cold start injector unless its really cold.
i have unplugged my one.
also some times they leak fuel into the intake when sitting and can flood the engine.
how is the afm , have you had it on a dyno and checked air fuel ratio's etc
MShimon
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Post by MShimon »

I once had a similar issue, it turned out to be a bad fuse.
1st 5er
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Post by 1st 5er »

MShimon wrote:I once had a similar issue, it turned out to be a bad fuse.
Which one?
mooseheadm5
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Post by mooseheadm5 »

Is this thing on?
a
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Re: HOT STAR ISSUES, LOOKING FOR REAL SOLUTIONS.

Post by a »

Fuse 1 is for fuel pumps, also check the relay. Temp sensor Also main relay and ECU are usual suspects.
eastside_m5
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Re: HOT STAR ISSUES, LOOKING FOR REAL SOLUTIONS.

Post by eastside_m5 »

I had a hot start issue for a while also. turned out to be the ecu. the mechanic re-soldered one of the circuits and it solved it. After that I was having an issue with it sputtering and I fixed that replacing the temp sensor.
tn535i
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Re: HOT STAR ISSUES, LOOKING FOR REAL SOLUTIONS.

Post by tn535i »

No response will = No REAL SOLUTION. Maybe if we ask harder...
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