2000 honda civic ex 5 speed manual d16y8 idle problems
so I've been having idle problems with my civic, I start it up and it idles at 3k for a lil then drops to 1.5k and surges from 1.5k to 2.5k rpms, I replaced the iacv, cleaned fhe throttle body, replaced fhe map sensor, bled the coolant, flushed coolant and put in oem blue honda coolant, no cel when all connectors plugged in, i put my finger over the hole for the iacv in the throttle body while it was running and the idle drops and smooths out to about 1.3k rpms, so I unplug the iacv and it stays at 1.3k and then I mess with the idle screw and if you bottom it out the idle will go to down to about 1.1k but idles kinda funny still, I checked for vacuum leaks and there are none, im at a loss..
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^ what slo_eg8 said and just chiming in here. Many times where I thought "I have no vacume leaks" I look a few more times and find some tiny pin hole or crack in a hose. I have also seen a gasket on a non honda engine get folded over once, instead of it laying flat it was crushed on bent and folded on itself which is pretty hard to mess that up but so many things are possible.
I always recommend replacing your 25+ year old brittle rubber vacuum lines with new ones.
I always recommend replacing your 25+ year old brittle rubber vacuum lines with new ones.
^ what slo_eg8 said and just chiming in here. Many times where I thought "I have no vacume leaks" I look a few more times and find some tiny pin hole or crack in a hose. I have also seen a gasket on a non honda engine get folded over once, instead of it laying flat it was crushed on bent and folded on itself which is pretty hard to mess that up but so many things are possible.
I always recommend replacing your 25+ year old brittle rubber vacuum lines with new ones.
thanks, do you have any recommendations on where to get new vacuum Lines? or just get different sizes and cut them to fit?
The OEM ones from Honda are pre bent and typically expensive. In the past I would just remove the individual line and take it to the auto parts store for them to match the thickness, inner and outer diameter and then cut it to the length. They usually have long hose reels of different sized line. If you ever need fuel line make sure it is capable of holding fuel and coolant for a coolant line. For vacuum line I have just used whatever line they had. typically they charge you by the foot based on the line. It should be around $2 a foot which once you get it you can just cut it with some cutters down the the right size. Always cut it too long rather than too short and if it fits too long you can trim some down after the test fit. You can always take more off but you can never put more back on. Such is life in the zone. Anyways the whole project should cost less than $40 and take you around 30 minutes to an hour. Better to be safe than sorry with vacuum lines. I personally never trust 25-30+ year old line. It could cause you to miss diagnose your car in the future. You could be chasing all sorts of wiring and idle air control problems, TPS problems, coolant/head gasket issues and what not. It is best to just replace all vacuum lines so that way you have peace of mind and sleep good at night. Also it might fix some issues you never knew you had and run better if you had a small leak you did not know about.thanks, do you have any recommendations on where to get new vacuum Lines? or just get different sizes and cut them to fit?
Be careful to check the new vacuum lines after you have installed them and driven around for a while, sometimes if the hoses bend a certain way or are not rated for vacuum pressure they may bend or collapse on themselves. I had it happen once, I just shortened the line and bent it slightly and it helped, it never was a perfect replacement but I never knew any issues with it after.
IACV unplugged and idle screw adjusted properly, it should idle at 450-550 rpms.
You still have a vacuum leak.
Let it idle, spray the fuel inejctors with brake cleaner. If it increases the idle, you have a leak.
Intake manifold gasket, fuel injector O rings, the shaft of the throttlebody, even a bad brake booster can create a vacuum leak.
Double and triple check. Plain and simple, even if you think you checked it all.
WE all miss shit!!!
Ive seen cracked TPS gaskets and even a cracked MAP sensor cause this
You still have a vacuum leak.
Let it idle, spray the fuel inejctors with brake cleaner. If it increases the idle, you have a leak.
Intake manifold gasket, fuel injector O rings, the shaft of the throttlebody, even a bad brake booster can create a vacuum leak.
Double and triple check. Plain and simple, even if you think you checked it all.
WE all miss shit!!!
Ive seen cracked TPS gaskets and even a cracked MAP sensor cause this
guys, would the wrong intake manifold gasket be a cause?😭
The, wrong, Intake manifold gasket probably does not seal.guys, would the wrong intake manifold gasket be a cause?😭
So, Yes, it would cause issues like this.
Regardless, it should be replaced with the, Correct, gasket.
99 and 00 civics had air injection holes for the Y5 and Y8 engines. Manifolds and gaskets need to match. You can use a 96-98 manifold and gasket to remove it.
Outside of that, a d15b7 tiny intake gasket would still seal fine, and a d16y8 large intake gasket can seal fine on the d15b7.
The only "wrong" intake gasket is just the air injection setups
Outside of that, a d15b7 tiny intake gasket would still seal fine, and a d16y8 large intake gasket can seal fine on the d15b7.
The only "wrong" intake gasket is just the air injection setups
thanks, I replaced it with the right gasket and now I can get it to idle but now if I give it gas it will start surging, what could be a cause of that?99 and 00 civics had air injection holes for the Y5 and Y8 engines. Manifolds and gaskets need to match. You can use a 96-98 manifold and gasket to remove it.
Outside of that, a d15b7 tiny intake gasket would still seal fine, and a d16y8 large intake gasket can seal fine on the d15b7.
The only "wrong" intake gasket is just the air injection setups
did you bleed the cooling system? do an idle relearn?
like Slo said, bleed coolant. Low or air filled coolant will cause the IACV that relies on coolant flow/temp to go up and down.
Double check the Idle screw. Snug it up all the way, then back off 1 or 2 full turns.
Double check the Idle screw. Snug it up all the way, then back off 1 or 2 full turns.
The bleeding of the coolant won't effect the idle in my testing. I used to have 1/4 turn ball valve to shut off the coolant flow to the IAVC and FITV, made no difference on the dyno either, so that would have been in 1999 on my D15B7
Dave's Honda Haven in Memphis, TN, where ZEX dynoed their cams and Nytrous kits.
Dave Steward - owner now Uncle Dave's repair.
Dave's Honda Haven in Memphis, TN, where ZEX dynoed their cams and Nytrous kits.
Dave Steward - owner now Uncle Dave's repair.
I replaced all the vacuum lines and bled the coolant and did the idle relearn and it idles now around 800-900 but if I give it gas it will start to surge and won't stop till I turn off the car and back on,any ideas?like Slo said, bleed coolant. Low or air filled coolant will cause the IACV that relies on coolant flow/temp to go up and down.
Double check the Idle screw. Snug it up all the way, then back off 1 or 2 full turns.
also when I unplug the iacv it idles perfect and it revs just fine and dosnt surge at alllike Slo said, bleed coolant. Low or air filled coolant will cause the IACV that relies on coolant flow/temp to go up and down.
Double check the Idle screw. Snug it up all the way, then back off 1 or 2 full turns.
sounds like you got the vac lines mixed up....
can you send a diagram? I'm pretty sure I have everything rightsounds like you got the vac lines mixed up....
I'm sorry but a pic of the porn I'm currently fapping to would be of no help, EVER!
I vividly remember the very last time i used this statement.I'm pretty sure I have everything right
I was wrong.
I got schooled.
I got humbled.
Never assume you're right. Instead, always assume your understanding is subject to change.
The side effect of which allows you to see the world at angles you may have never thought were possible, allowing you to understand and derive meaning ways previously unfathomable.
I'll get off my philosophy horse now
This probably did nothing to help you with your car, I'm sorry.
Pop the hood, get the engine warmed up, and spray brake cleaner in little bursts all over the intake manifold and brake booster. Not all at once. Spray a spot, listen for a change in engine operation and RPMs.can you send a diagram? I'm pretty sure I have everything right
Fuel injectors, intake manifold gasket, throttlebody, the SHAFT for the throttlebody, around the IACV/FITV, around the MAP sensor and TPS sensor, and around any vacuum line.
When the IACV is unplugged WITH NO VACUUM LEAKS, you should be idling proeprly at 450-550 rpms
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