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Old 03-24-2009, 09:20 AM   #1
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Default Idle issues

*I posted this under a different existing thread, didn't get an answer*
I was having issues with idle being too high (1500-2000 rpm) and could reduce it using the idle screw. I tightened every intecooler clamp..etc, still, issue was present. I had seen other threads suggesting it is the IAC.
So, I took off the Throttle Body/IAC. I used fuel line clamps to block the coolant lines so I don't have to drain all the coolant.
The pictures show what I found, but I have some questions:
1) Is it normal to have oily residue in the intake manifold? If yes, why would it be there? Is there recirculation?
2) Should the throttle plate in the TB have a small gap around the edges? My picture is blurred, but you can see light around the edges? Normal?
3) I found the oily residue also on the rubber tubing connecting the intercooler tube to the TB and in the intercooler tubing... Normal? I have a feeling it is not but I am new to this so I don't know.
4) I tested the resistance on the IAC terminals as the manual suggests and it is 9.6 ohm which is in the range of normal... Is it a sign it's OK or could it still be bad?
5) I don't know what kind of fluid it is on all these parts, but it could be PWS fluid - someone suggested that I have a leak under load from the original build thread I posted (see pictures here: https://www.miataturbo.net/forum/t27300-9/ ). Is it possible for that to get though the turbo rubber tubing and into the system or is more likely oil and from where??

I am currently soaking the IAC and TB in throttle body cleaner and I will let them sit there until tomorrow, then put everything back together and give it a try. I was also looking for a new IAC on Craigslist, on the Classified on this forum...etc no luck. So, I called FM and they have two from salvage, but I won't find out about that until Friday probably.

Here are the pictures and please let me know what you think:

















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Old 03-25-2009, 06:34 PM   #2
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I put everything together with a new gasket for the IAC. I don't have another IAC yet, still idles at 1500-1600 rpm. Also, the boost gauge reads 15 on Vac instead of the 20 I was seeing initially. The wideband reads between 14 and 15 at this high idle.
I cannot find a leak at this point and I retightened everything, but I have not made a leak tester either... still need to do that.
Any ideas??
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Old 03-25-2009, 07:06 PM   #3
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have you tried plugging the hose going to the IAC? That'll tell you if it's the IAC at least. It could be any of the vac lines. Start capping things off and spraying starter fluid around your motor to find leaks.

All that oil is likely from your turbo seals being blown. your PS should not be getting into your intake. Check your turbo and make sure the drain is free-flowing.
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Old 03-25-2009, 07:09 PM   #4
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get a can of brake cleaner. spray it around all the flanges, you'll find the leak when the car bogs.
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Old 03-25-2009, 10:35 PM   #5
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Quote:
Originally Posted by TrickerZ View Post
have you tried plugging the hose going to the IAC? That'll tell you if it's the IAC at least. It could be any of the vac lines. Start capping things off and spraying starter fluid around your motor to find leaks.

All that oil is likely from your turbo seals being blown. your PS should not be getting into your intake. Check your turbo and make sure the drain is free-flowing.
The IAC just has two coolant lines running to it, I think. I will try all the vacuum lines and see - starter fluid.. What happens with starter fluid?

How do I check the turbo? Do I have to take it off ?

I've only had it for a few weeks on the car an only running may be a week out of that... could it have happened during that time? It's brand new.
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Old 03-25-2009, 10:36 PM   #6
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Quote:
Originally Posted by Braineack View Post
get a can of brake cleaner. spray it around all the flanges, you'll find the leak when the car bogs.
I can try that tonight hopefully... I have a can of that
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Old 03-26-2009, 01:10 AM   #7
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I was surprised tonight. The good news: I took the car out for a ride, 20 minutes, when I stopped, it idled at around 900! It was slow getting back to idle, but it did idle normally. So, I returned from my destination (20 minutes again) and I opened the hood. I could hear a hissing noise - it was by the injectors. I used brake cleaner spray (Thanks Braineak) to find it and I think one of the injectors is where the leak is. So, I have to address that in the near future.
I sent Stephanie an email regarding the possibility of blown seals on the turbo... we shall see (I appreciate the input TrickerZ)
The vac reading is still hovering at 15 instead of 20 like I saw initially (at idle), and the A/F meter reading is between 14 and 15, both probably can be explained by the leak by injectors...
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Old 04-02-2009, 01:10 AM   #8
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I tried the can of brake cleaner and found a leak around one of the injectors. I took off the intake, thought I fixed it, turned the car back on and the leak is still there, a little less noticable. Not sure what I have been doing wrong on that.
I took pictures of the intake. Some of it may be TB cleaner that I used but it looks pretty dirty to me... any ideas?
I also noticed what I think is knock when I am driving at 60mph, then hit WOT, going to 80+... I hear random clicking... is that what knock is? I tried it a few times to confirm that I heard it and yes it's there. I use XEDE so anyone with that piggyback can chime in on where I can adjust timing or add fuel. My Dynoscan is showing rich mixture at that point, so, timing may be the issue.
Here are the pictures of the intake manifold:








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