Comments on ISR mod...
04-26-2005, 11:50 AM
#21
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CJ-
I am talking about these two lines, but mainly the top one:
The top one goes to the Fuel Pressure Regulator, and we have found that this can cause the engine to run overly rich when plugged - which means it does have an effect on A/F ratio, albeit a small one.
So what did you do with those lines?
I can see from the other guys website that you are speaking of the crankcase ventilation hoses in your previous posts.
I am talking about these two lines, but mainly the top one:
The top one goes to the Fuel Pressure Regulator, and we have found that this can cause the engine to run overly rich when plugged - which means it does have an effect on A/F ratio, albeit a small one.
So what did you do with those lines?
I can see from the other guys website that you are speaking of the crankcase ventilation hoses in your previous posts.
04-26-2005, 11:57 AM
#22
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Is it possible that my 03 3.4 and your engine is different? I'm just wondering. I think that what I was calling vacuum lines are, in fact the PCV return hoses. In that case, it changes everything, and I feel like a knucklehead.
04-26-2005, 12:15 PM
#23
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Yeah, some 3.4L motors varied slightly. But as far as I know, they all retained the FPR line hook-up. Why don't you post a pic of your current set-up when you get a second. I would like to see how you routed everything.
We found that capping the FPR off completely caused a rich condition and slightly worse performance (at least that was my finding). I went back to hooking it up to the front silencer plug location. As soon as I get this SC'r put on I won't have to worry about that anymore though.
We found that capping the FPR off completely caused a rich condition and slightly worse performance (at least that was my finding). I went back to hooking it up to the front silencer plug location. As soon as I get this SC'r put on I won't have to worry about that anymore though.
04-26-2005, 12:24 PM
#25
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Originally Posted by SC4Runner
Id just throw this in here, but, last week I went to my "Yoda", who is a specialist for Toyota trucks. He owns his own garage here, and is realllllllly knowlageable for all years of Toyotas.
Anyways, I was talking to him about the ISR mod and he said that I should put back my boxes. He made a good point about Toyota spending lots of money in technology to develop a good intake system, and why the boxes were there in the first place.
Basically you have waves of air-flow to your engine. The boxes basically take the waves and smooth them out, and thus create a smoother engine.
Of course this is just one persons opinion.
My opinion is that its was cool and stuff, but, I dont know if I noticed any power gains or sound difference. The one thing I noticed is the LOUD WHISTLE noise when cruising.
Im most likely oging to take it out, but, im too interested other things right now
Anyways, I was talking to him about the ISR mod and he said that I should put back my boxes. He made a good point about Toyota spending lots of money in technology to develop a good intake system, and why the boxes were there in the first place.
Basically you have waves of air-flow to your engine. The boxes basically take the waves and smooth them out, and thus create a smoother engine.
Of course this is just one persons opinion.
My opinion is that its was cool and stuff, but, I dont know if I noticed any power gains or sound difference. The one thing I noticed is the LOUD WHISTLE noise when cruising.
Im most likely oging to take it out, but, im too interested other things right now
04-26-2005, 12:59 PM
#27
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Here's one shot of the engine bay.
You can see both breather filters installed on the return lines.
That's pretty much the drill...
You can see both breather filters installed on the return lines.
That's pretty much the drill...
Last edited by Tacoclimber; 04-26-2005 at 01:06 PM.
04-26-2005, 01:51 PM
#30
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Christian, I think I found it. It is on the right side of the engine, nowhere near the intake hose. ? Different design, I suppose. There is a brass pipe that runs under the intake plenum. On the front side, the hose (originally) attached to it runs to the silencer box. On the rear, the hose attached to it runs to what I believe is the PCV valve, or at least part of the system.
04-26-2005, 01:58 PM
#31
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Originally Posted by <96 Runner>
Hey Mark, how much do you know about this line? I knew it went down to the PS and had something to do with it, but I was never sure exactly what. In summary?
The bottom line is that it's a boost for the PS hydraulic pressure that's based on manifold vacuum. If you look at how the lines are, one side taps before the TB and the other taps in after. When the difference between the two is "at some point" then the PS pressure is kicked up a notch. I called it a "coldstart boost" 'cause it was explained to me that it will kick in when the engine's cold, but to me, it seems like it will kick in anytime the difference between the pre/post TB pressure is high enough - like when you floor it.
04-26-2005, 02:05 PM
#32
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Originally Posted by Tacoclimber
Christian, I think I found it. It is on the right side of the engine, nowhere near the intake hose. ? Different design, I suppose. There is a brass pipe that runs under the intake plenum. On the front side, the hose (originally) attached to it runs to the silencer box. On the rear, the hose attached to it runs to what I believe is the PCV valve, or at least part of the system.
fwiw, the PCV valve is in the top of the right side valve cover, near the front, you can see it in your 2nd pic. It's the blueish piece in the lower right corner with the hose coming off the top and running to the TB.
Last edited by midiwall; 04-26-2005 at 02:06 PM.
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