I was wondering if anyone else ran into this problem when they did this. I did the mod and took it out for a test, the car certainly had more pep then before but to my dismay there was something else. When the car idles it acts like it is having an argument with itself. It will bounce between 1400 and 700 rpm at about one second intervals. When I hook up the coolant line again it idles just fine. Is there any way to keep this mod and a good idle.
Remove the rubber air duct from the TB and look inside the TB (with the throttle closed), you'll see two holes on the left side.
You need to plug the lower one. And DON'T plug the upper on because you will not have idle at all.
Because you did the coolant bypass mod, this lower hole is always left open. So there is always air bypasssing the throttle. That's why your idle is acting strangly.
I put a 1/2'' industrial natural rubber wire in it. About 1.5'' long. The hole is just a little bit larger than 1/2''. So after chopping the end of the rubber wire to totally clear the air passage, I screwed a small wood screw in the middle of it in order to make a perfect seal with the TB casing.
BTW, i had to remove the TB because the first time I tried to plug the hole, the rubber fell completly inside. Removing the TB is very easy. Unplug everything that is attached to it including the throttle cable. There is 2 bolts and two nuts to remove (making a pefert square pattern). The TB is about 4-5'' long. Removing the TB will alloy you to see how the end of the rubber wire will make contact with the inside wall of the TB. It will also allow you to install & remove the rubber many times in order to chop it perfectly as many time as needed until the perfect fit.
I hope my english is easy for you to understand.
feel Free to montact me for further precisions...
***THis is not my write up, i take no credit it was written for my by a guy named Patrick***
__________________ 2.233 60'!, 15.533 at 88.96mph?
I/H/E Konis/Neuspeed Race .."the Prelude is the best Integra ever made......." - Car & Driver, 1999
i just cleaned out my intake manifold/tb with some valvoline stuff and my idle is the exact same as this person explained. it jumps from about 600-1400 EVERY time i go to idle.
what do i need to do? that post up there made no sense to me. i didnt do the coolant bypass mod so that shouldnt be the problem.
Originally posted by $$lude His write up doesn't make sense to me. So I have yet to do the mod. God that would be nice to do Saturday. Anybody have any better pics?
Well if you do have any questioon go for it buddy....
I'm stuck on which hose to move. I have had my head in my engine bay looking for which one. His picture is pretty small so I didn't see which one to move.
Originally posted by 4bidden i just cleaned out my intake manifold/tb with some valvoline stuff and my idle is the exact same as this person explained. it jumps from about 600-1400 EVERY time i go to idle.
what do i need to do? that post up there made no sense to me. i didnt do the coolant bypass mod so that shouldnt be the problem.
Well, then check your idle control valve!!!!!
At idle, the throttle is CLOSE. So the air has to pass SOMEWHERE!
The upper hole inside the TB (just upstream the throttle) is an air passage for the IDLE CONTROL VALVE controlled by the ECU. If your coolant level is ok, check the Idle control valve, it might be the problem.
The lower hole inside the TB (just upstream the throttle) is an air passage for the FAST IDLE THERMO VALVE. This valve is open when the coolant is cold. ANd closes with the coolant being warm-up. And totally close at normal engine temp. THat is why its call FAST IDLE THREMO VALVE. When there is not enough coolant in the system, the valve never close properly. SO WHEN DOING THE COOLANT BY-PASS mod, you need to block this air passage.
Originally posted by $$lude I'm stuck on which hose to move. I have had my head in my engine bay looking for which one. His picture is pretty small so I didn't see which one to move.
Well never easy without pictures....
If you look at the coolant thermostat housing, there is 2 hoses attached to it (2 ports). The coolant flows from one on them to the intake manifold (the connection is under the TB). Then it flows back from the intake manifold to the coolant thermostat housing. All you need is to make sur that the 2 coolant thermostat housing ports are connected together (not flowing to the intake manifold anymore)... you can do the same thing with the intake manifold (not required)
I just wanted to say that this is a useless mod, i've done it to my car, and it made no difference people claim that it makes a difference in cooling, all it really does is keep your car in fast idle longer,, since its taking longer to reach the certain temperatures... no one has dyno'd this mod, and if they did it would not produce any power in my opinion, dont waste your time on it.. no power from it, just my experience.
Well, here are a few points (from MY experience...)
- The cold idle is actually at a LOWER RPM (than normal) if you did the mod properly (plug the lower hole)
- I have definitely noticed a gain, but of course mostly during relatively cold climates (especially at night...). It is simply very great.
- Since the intake is in direct metal contact with the engine, the lower intake temperature difference can only be noticed after cruising for a few minutes, since only the air entering the intake is cooling it down (Also the EGR is warming the intake manifold...)
- When at idle for q while (like when waiting inline for a next 1/4 mile run), the intake manifold will get as hot as without the mod, UNLESS you idle the engine at 3000RPM to cool down the intake.
I have definitely seen a gain with this mod.
Note : To dyno, this mod, you have to idle the engine at 3000+RPM for a few minutes before the dyno run, since there is probably no Highway to drive on inside the building
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