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Hey everyone, Im new to Honda's and i just recently purchased a 03 for my son (first car, and a chance for him to learn a little about fixing a car). The car runs and drives, however the idle is very erratic. The idle will typically set at about 12-1300 RPM but when the car if placed into gear and load is put on the motor it shakes quite a bit and probably drops to about 300-500 rpm, it has never died because of this but it sounds rough and feels rough. I have also seen the car rev up and hold for a while 2-3K for no apparent reason.
I have been reading like crazy about the car since i have no previous knowledge of hondas, and it seems that idle issues are fairly normal with them. The one issue im finding is that most issues are the IAC valve which i have already replaced and relearned, and the symptoms most of the time seem to be a idle that goes from 500-1500-500 over and over. Mine never does that, it just stays at 1300ish and then drops way down when load is placed on the motor and it seems the IAC never really is able to recover the RPM. I have no CEL, so i cant use my scanner to pull a code as there isnt one. As far as i know there is no problem with the head gasket. It seems to hold water fine, and there is no overflowing of the overflow reservoir, and the oil isn't milky.
My plan at this point is to pull the throttle body and fully clean it with carb cleaner, spray some carb cleaner around the intake and hope there is maybe a vac leak (cant seem to really find much on vac diagrams) and i was planning to pull he MAP sensor clean it with some MAF cleaner i have and inspect its Oring and put it back. Im hoping that the combo of these things will help me get this resolved.
With your guys knowledge base is there another area i should check, any known honda problem points or anything else i should do along with my current plan?
Probably not the throttle body. If that were gunked up it would stick open, but it's unlikely to cause idle issues.
You said the iacv is good, but you can test it by plugging its port inside the throttle body entrance or unplugging it.
To check for vacuum leaks, the easiest thing to do is to remove everything from the intake, down to the throttle body. Block the throttle body intake compleatly, with a flat card (plastic, heavy card board, wood). If it still runs, there is a vacuum leak.
After that, you can use a smoke machine to locate it.
.........
It could also be fuel related.
Check fuel pressure at the rail. Though they're supposed to be lifetime fuel filters, mine clogged and eventually caused stalling.
Thanks MAC25. what do you mean stripping everything off the intake? Is there a lot of Vac lines used on these motors? I know older motors tended to have a lot of them, but it seems the new motors have less and less vac lines.
The IAC is brand new, is there a way you know of to test it?
Thank you for the info, im definitely going to try the hand or cardboard over the TB for sure, that seems like a quick and easy way to rule out a vac leak or not.
I do have a Bluedriver bluetooth OBD2 reader. It does have live data reader available however i just got it and have not had much time to "play" with it and understand the best way to use it.
I may have to plug it in and check it out. I know the CEL isnt on, and i checked the codes and nothing was active. I cleared the one code i made it have by forgetting to plug in the intake air sensor. LOL
So ive been trying to do a little testing to see if i can find my problem and this is what Ive come up with thus far.
* tested for vac leak while the car was running with MAP gas, i wasn't able to notice a difference in engine speed (however i could be doing this wrong) (i think im going to try to test this again as i was a little under the gun for time)
* Randomly i got a P1457 code - EVAP system leak detection (canister area) - the research ive found leads me to the vent solenoid towards the back of the car. ive read you can test them by putting 12v and ground to the pins to force the valve (which should be normally open) closed. I can def do this, however i am wondering if there is a specific pin that needs 12v and the other ground. I dont want to fry the solenoid. i know most sol dont care what is + and what is - but i want to be sure.
* i cleared the CEL and it hasnt come back yet, but i figured i would test the solenoids for the purge valve by the throttle body and the one under the car and see if i can hear them click.
* i picked up a bunch of Vac line caps to cap off some vac lines to test if ive got a leak if the MAP gas and break fluid test doesnt turn anything up. From what i can gather there is only about 4-5 vac ports on the car?
* I randomly while looking around the car noticed that the exhaust manifold has a small crack just below the o2 sensor. Do you think there would be any problem with me busting out the welder and fixing that little problem? Also would that potentially cause my issues?
OK, i got a chance to look at the car a tad today. This last week it popped a P1457 (evap control system leakage (evap canister area)) I cleared the code feeling it was likely more from me monkeying around with the car a bit and i have not seen the light return.
Here is what i have currently
-the car wants to idle at about 3k with no AC on
-1800 with the AC on
-about 1200 with the AC on and in Rev.
This seems a lot like a vac leak to me, i pulled the air cleaner and put my hand over the throttle body and i was able to stall out the car. This doesn't really surprise me since im not thinking my vac leak is bad enough to keep the car running by itself.
However while i was messing with the car I decided to try using carb cleaner to test for Vac leaks, while spraying all around the IAC, the purge valve, and all around the throttle body and MAP, i started spraying around the injectors and as i got close to the timing belt area on the side of the intake where it meets the head i found a spot where if i spray carb cleaner im actually able to get the car to struggle to stay running by spraying that area. I believe that is my source of the leak, i tested this with the air cleaner off and thinking that maybe i was pulling vapors in to the TB i put the air cleaner back together and sprayed it again in the location and found that i was again able to cause the engine to struggle.
What are your guys thoughts? Is there anything else in that area that could be causing my issue? Im thinking i am going to get a full Non EGR intake gasket set from Felpro (my LX doesnt have a EGR) and replace all the gaskets probably the injector orings and since the PCV is so cheap i may pick one up too and swap it out.
What are your guys thoughts? do you think im on the right track?
I would check to make sure the intake bolts are not loose in that area, set torque wrench to 15ftpounds.
The plastic intake uses 4 rubber gaskets (o-ring): to seal to the injector base plate which uses a coated metal gasket to seal to the engine. Be sure to remove any stuck on coating left behind on the plate/head before replacing.
I have horribly large hands for fiddling with those intakes, and what should take 5 minutes seems to take me 45 for that center lower nut.. Highly suggest having an assortment of small tools. Offset wrench, ratcheting wrench ect.
Thanks Slumpertcivic, I would assume its not an issue to re-torque the Oring style gaskets but will i run into any issues with the coated Metal gasket by re-torquing it? Yeah i have heard that the bottom bolts are a bit of a pain to get to. I have a good assortment of tools im hoping i have all i need to get to them.
I think i am going to try to tackle this project this weekend. I got my new gaskets in (felpro), new injector Orings, and a new PCV valve since im in there. One question i have is that Felpro has gone to a solid metal gasket from the head to the injector plate. My understanding is that the old gaskets were coated apparently. Im a little concerned about this as i am replacing the gasket now due to a intake vac leak. Do you guys feel there is any reason to use copper spray to give the gasket a fighting chance or do you think 17ftlbs on a steel non-coated gasket is adequate?
My kit was only the one gasket, it didnt come with two its Fel-Pro MS96390
It is defiantly an intake gasket, i actually called FelPro and asked them to look it up. Numbers stamped in the gasket are correct, its a Non-EGR gasket, no small holes, but from what Felpro says its the direction most automakers are going with their gaskets. I just wanna make sure this thing seals up so i was contemplating putting the copper spray on it to give it a tad more sealing ability.
Thought before i put the spray on i would inquire on here and see what everyone thought.
Yeah thats the exact one i got. I called Felpro and asked them the same question and they said that the picture was of the old style and they no longer make it that way. The new gasket has "felpro 96449" laser etched in the top of it which is what they told me i would find if it was the correct manifold gasket. The 1star review was because that gasket is for the non-egr 1.7L, and the person buying it needed the EGR version with the small holes drilled in it. The computer will toss a CEL if those holes aren't there and you have a EGR system, it basically blocks it off from what i can tell. LOL my car has no EGR so i should be good.
I think im going to just pull it apart and see what is in there. I may just stick with Felpro (ive always had good luck with them) or i may decide to just go get a OE one or another brand. Not sure, i think first ill get it torn down and see what im working with.
So i tore into the car this weekend and found some issues along the way. I replaced the intake gasket which was a incorrect felpro gasket EGR gasket on a non EGR car (so someone has already been into this car), i found multiple loose bolts along the way, i replaced the 4 rubber intake gaskets, the throttle body gasket, all 8 injector Orings, and the PCV valve. I also found a small rubber vac cap that was cracked which was directly above the PCV port on the intake. I got that replaced and put everything back together torqued.
I performed the relearn on the car after all this and found that my cheap amazon IAC made the car do the idle hunting thing (up and down over and over). I swapped the original IAC back on the car, did another relearn and that hunting idle stopped however it still wants to idle at 1300-2000. It does feel better, but its still not correct.
I am thinking my next step is to do another carb cleaner spray test to verify no more vac leaks at the intake, injectors, throttle body, and around any hoses. If that checks out im thinking i might pull all the vac lines off the intake and plug all of them with caps and see if i can get the idle under control. If so start replacing each line and checking for correct idle till i find which line is causing me the issues and fix. If nothing changes with all Vacs off and capped i might try putting my finger over the IAC port inside the TB and see if that slows the engine idle as a test to see if the IAC is truly controlling. My code reader cannot see the IAC% but i can see other things like throttle pos (which seems good), engine temp (seems good)
Do you guys see anything wrong with my test logic or is there anything else i should check? I am suspecting the IAC, but i dont know the best test to verify. I "think" i have the vac leaks ironed out but my IAC is the original and im not sure its working properly.
Important step of the relearn process is to follow the relearn process precisely.
I fumbled with that myself once, even when I got it right, still had to take my civic for a spin on the freeway before the idle relaxed.
I believe I can see MAP, I will have to double check and verify that. I pulled off the fi fuse and left it off for about 30s. Then I plugged it back in and made sure no fan, no ac, no stereo, no brakes, no throttle and started it and let it idle till the cooling fan came on 3 separate times then I turned it off and started it. Does that seem good? Cars don’t take long to warm up here in AZ as the garage is already 100+, I’ve seen a few different ways to do it but waiting for the fan to come on seems to be the time to turn it off in each method I’ve read.
Ive read that it can take up to a tank of gas to relearn fully but I’m already above where I should be and it doesn’t seem to want to come down any more.
Ok ok I’ll try the finger over the iac port and see what it does. You wouldn’t happen to know what the iac does if you unplug it while it’s running so you? Does it close and kill the motor? I’m trying to figure out the best way to test the iac for operation and see if it’s binding up or something.
** Update**
I got a chance to dig into the car today as it started acting up again. The idle is still about 1200-2000. I took the chance today to spray all around the intake and vac hoses and was not able to change the idle speed. My next step was to pinch the brake booster line with pliers to stop the vac to that system, i pulled the purge valve line and plugged that vac line with a vac plug as well as plugging the line with a 1/4 extension, i pulled the PCV hose line, shoved a sharpie in the hose and put another vac line plug on that port as well. at this point i performed the idle relearn (to no avail, it still idles high) I then took a piece of plastic to cover the IAC port and was able to kill the motor. I then restarted the car and slid the piece of plastic over the port just enough to idle at about 700 and it sat happily idling at that speed. I then released the brake booster clamp (no issues) still idled smoothly at 700. I then added the purge valve (the motor sped up as i introduced the vac leak and slowed back down as i put the vac line back in place), i then did the same the the PCV and still found the car to idle smoothly without any issues until i removed the plastic thing that was covering the IAC port and then the idle returned to its high idle.
I scanned the car as it had a CEL today and i found P1129 and a P1505. I found a loose bolt on the throttle body once i took the air cleaner off. I think the 2 codes i had were a result of a vac leak from that loose bolt (not sure how that bolt got loose, i guess i didnt get it torqued last time or something) I cleared the codes and i took it for a ten min drive or so and nothing has returned. The only thing i can think of when it comes to the idle is to replace the IAC with a new one since i cannot get the idle to come down using the IAC however i can when i physically block some of the IAC port with something.
I know that Honda parts are going to be the best, but does anyone have a recommendation on a replacement brand. Ive been looking at rockauto to see whats available. Looks like airtex\wells is one brand available and Standard motor products are the two i can get. What do you guys think? I got a cheap-o one from amazon for like 20 bucks but as expected it was junk and made the idle surge so i swapped the original back on the car.
