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2013 Subaru BRZ
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Discussion Starter · #1 ·
First, I was not able to start the car in two tries 5 days ago. See here:

http://www.toyotanation.com/forum/1...o-start-symptom-after-iac-valve-cleaning.html

Today I tried 6 times and it still would not start. The car did crank. So I had to think of something else. This is what I did.

1. I shifted to neutral and tried from neutral. No go. So not the neutral safety switch issue.
2. I shifted to neutral, depressed gas paddle, then tried to start. The car finally started after some struggle. So it has to be either air or fuel.
3. I left the car in idle and it did not die afterwards.

So what is the issue now? If it is a clogged IAC, why didn't the car die afterwards when idle? I did clean IAC valve a couple of weeks ago. Is it possible that I messed up something last time?

If it is fuel problem, what should I proceed to further diagnosis? I have a bluetooth dongle with Torque Pro installed in my phone. Is it going to tell me something I do not know?

Thanks a lot for your help. Ideally, I want to precisely pinpoint the issue and solve it. Any help is greatly appreciated!
 

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That sucks and I suspect the iac just because it was recently messed with. I would think that torque could show you fuel trims and that might be helpful if you know enough about them to see if something is out of wack. I have it as well and it's a great tool but I am sorry to say I am not enough of a mechanic to really be of more help. I am sure one of the resident guru's will be along soon with more advice :)
 

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2016 Rav4
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OP, what else, besides cleaning the IAC was done to the car between the time it was working fine and now?
also, do you have any CEL's?
with torque, graph out the short and long term fuel trims to see if there's more than a 10% difference between the 2 or see if the long term is more than about 5% rich or lean.
does it do this warmed up? if so, does unplugging the ect fix the problem? and/or are you able to check the resistances hot and cold of this sensor per the manual to ensure it's not choking the hot engine, if this is the case?
checked for vacuum leaks in the snorkle or other old hoses using cigar smoke, etc.?
all this assumes normal and timely maintenance such as plugs/wires/disto/rotor/pcv/fluids/filters, intake/egr/iac cleaning, etc.
tony
 

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2013 Subaru BRZ
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2,232 Posts
Discussion Starter · #4 ·
No CEL. The only other thing I can remember is that I broke a hose during cleaning IAC valve and put it back after taping it with Gorilla tape. The connection looks secure, but I cannot be sure that it is not leaking air or change the vacuum level. I started a thread here:

http://www.toyotanation.com/forum/1...001/1388033-what-part-number-vacuum-tube.html

The part should be a fuel vapor hose for the EVAP system. I guess the fuel vapor will go to intake via this little hose. The 5SFE can run with a very big crack on the big fresh air intake hose, so It seems impossible to me that a small leak on this hose would have any impact. But what do I know? If I can pinpoint that the culprit is this little hose, I shall have to pony up for the real hose though.

I shall measure LT/ST fuel trim tomorrow and load the data/group tomorrow. Thanks for the help.


First, I was not able to start the car in two tries 5 days ago. See here:

http://www.toyotanation.com/forum/1...o-start-symptom-after-iac-valve-cleaning.html

Today I tried 6 times and it still would not start. The car did crank. So I had to think of something else. This is what I did.

1. I shifted to neutral and tried from neutral. No go. So not the neutral safety switch issue.
2. I shifted to neutral, depressed gas paddle, then tried to start. The car finally started after some struggle. So it has to be either air or fuel.
3. I left the car in idle and it did not die afterwards.

So what is the issue now? If it is a clogged IAC, why didn't the car die afterwards when idle? I did clean IAC valve a couple of weeks ago. Is it possible that I messed up something last time?

If it is fuel problem, what should I proceed to further diagnosis? I have a bluetooth dongle with Torque Pro installed in my phone. Is it going to tell me something I do not know?

Thanks a lot for your help. Ideally, I want to precisely pinpoint the issue and solve it. Any help is greatly appreciated!
OP, what else, besides cleaning the IAC was done to the car between the time it was working fine and now?
also, do you have any CEL's?
with torque, graph out the short and long term fuel trims to see if there's more than a 10% difference between the 2 or see if the long term is more than about 5% rich or lean.
does it do this warmed up? if so, does unplugging the ect fix the problem? and/or are you able to check the resistances hot and cold of this sensor per the manual to ensure it's not choking the hot engine, if this is the case?
checked for vacuum leaks in the snorkle or other old hoses using cigar smoke, etc.?
all this assumes normal and timely maintenance such as plugs/wires/disto/rotor/pcv/fluids/filters, intake/egr/iac cleaning, etc.
tony
 

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2016 Rav4
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5,764 Posts
can't hurt to replace the broken/taped hose. it's always a good idea to fix the simple stuff that you know about like split hoses, cel's, etc., so they don't develop into bigger problems later on.
if your ltft is high rich, that would point to a vacuum leak or something leaning out the system like a dirty fuel filter sock, clogged fuel filter, etc.
tony
 
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