I don't need the opinions about me being a dumbass for missing a shift, i already feel stupid enough. With that said, my basically bone stock 90 CRX Si ran fine with no CELs until right after i messed up a shift.

Now i'm reading code 1 after a few minutes of driving, and i have an irratic idle. if i unplug the TPS, the idle problem goes away. I'm thinking IACV or IM gasket?? any ideas?? besides throwing rods and dropping valves, what normally happens when an engine is revved that high? thanks in advance

Shawn

 

There is no way you hit 11K in your almost stock car.

 

First, you did not rev the engine to 11000 RPM. Had you done that you would have most likely destroyed the engine.
Second, the code you are getting is O2 sensor which is not related to the TPS.
Get a new O2 sensor from an auto parts store and replace the one in your car.

Reset the ECU and see what happens.

 

fuel shut off for the stock crx si is at about 7200 rpm and the tach only reads to 8000. How did you come up with 11000, just wondering

 

Sure you can go past the rev limit...if you mis a shift on the downshift say going from 3rd to 2nd instead of 4th the motor will go past the rev limiter as you are actually making it spin past the rev limiter so it is actually spinning say 9000rpm even though there is no fuel.


How do you know its going 9000 even though your tach only says 8000?...you can feel it in your wallet


[Modified by 89civicdx, 6:10 AM 3/8/2003]

 

i've pegged my tach needle by going from first, 7200 rpm, 2nd, 7200 rpm, then accidentily shifted back to first.. only harm done was a flipped alt. belt.. hahahaa. that sucked... so don't feel bad you missed a shift, i'm worse... oh yeah, i messed up my tranny pretty good.. but the car still ran for like 6 months untill my beee series swap..

 

this is correct. yes, i did rev my engine to 11,000. im not an idiot, i know it sounds crazy. i was at redline in 3rd when i shifted into 2nd. no fuel at 11,000 and i thought my rods were gonna come through the firewall. but they didn't. don't call me BS on this one, because it isn't.

with that said, i got a bosch oem replacement O2 sensor today, problem solved with the code 1. still has an irratic idle. today i took off the IM and cleaned the injectors, IM, TB, and replaced the vaccum lines.

i think maybe the EACV is bad. not throwing a code anymore, and i am almost damn sure i don't have any vacuum leaks. what else could cause an irratic idle? goes from 1000-1500 over and over. if i disconnect the TPS, it idles fine.

also replaced the oil pan gasket today, and the spoon plugs were clean. i figured they'd have damn chunks of bearings on them. i guess i got a super-engine.

 

Erratic idle is caused by bent valves. I did the same as you once, on the race track. Came off the last corner onto the front straight, out of second. Tried for 3rd. Messed up shift linkage got me 1st. Tach needle on an Autometer 10,000 rpm tach disappeared into the area that is painted black for the light bulb (12,000 rpm). The car ran fine. Drove it back to the pits. But it would not idle. Had to hold the engine at 1,800 to 2,000 for it to keep running. Still made great power though.

This motor was a carbed 1.5 litre 1986 Civic 12 valve. We bent the 4 exhaust valves.

 

sounds like fun. im glad theres at least 1 person who believes me. so you think i bent the valves, huh? did it mess up your valve seats? or did you just replace the 4 valves and call it a day? wouldnt bent valves cause excessive valvetrain noise that i would hear? oh wel..........

edit- the irratic idle is only after it warms up. i was gonna bypass the coolant lines on the EACV and see what happens. if it stops doing it, ill just replace the EACV. if it doesn't help, ill replace the valves/head. thanks a lot for the info


[Modified by 22lbGS-R, 9:40 PM 3/9/2003]

 

if you have an erratic idle, you should do a compression test. If you fail, then you must have some bent valves... not good. good luck

 

man that would suck if you bent some valves that would mean alot of work,

 

thats a very good plan, a compression test will save you a lot of time/money/effort on a new set of valves and give you a very quick and precise estimate of the damage to the valves and seats as well as the piston rings, but even though you're idle isn't gone, I'm afraid the possiblilty for bent valves is too great, the heat generated by the speed of both the valvetrain and the piston movement would weaken the metal tremendously and for one thing your vavles I'm sure are not meant to handle that speed and so valve float would leave your valves hanging out in the cylinder and those pistons are moving so fast there is such a tiny window for the valves, so I say hope for the best but expect the worst and do the compression test for sure!


[Modified by hondavtecfanatic, 5:06 AM 3/10/2003]

 

Well by god, i reckon i'll buy a leakdown/compression tester from the Snap-On guy today. (i'm not that redneck, BTW) I've been wanting to buy one, just looking for a reason. Now i have one

 

I heard the same scenario one too many times!
a leak down/compression test will give you the answers you need!
Cylinder 1 and 3 will most likely have lower compression than 2 and 4..it's a Honda!
You also may have had a little blow-by and simply burned a valve which also may cause a "rough" idle.....Good Luck...Happy Hunting!

 

I heard the same scenario one too many times!
a leak down/compression test will give you the answers you need!
Cylinder 1 and 3 will most likely have lower compression than 2 and 4..it's a Honda!
You also may have had a little blow-by and simply burned a valve which also may cause a "rough" idle.....Good Luck...Happy Hunting!

 

i'm not trying to make you mad.. i believe you over-revved your engine.. but how do you know you went to 11k? autometer 12k tach? just wondering why you're stuck on 11k. hehehe

 

I just did a little math. i figured that 7300 rpm in 3rd was around 11,000 in second. im not totally sure, and i really don't care. the 11,000 isn't my problem,the irratic idle is. all i saw was my tach needle smack the bottom of the gauge bezel. i'm not trying to sound like a badass by saying my engine went to 11,000, because it's ****** stock. maybe it hit 7400, does that make you happy??

anyhow, i revved it way past 9500-10,000 and now it has problems. when it happened, i ducked for flying rods/valves/chunks of pistons, but it continued to run fine. when i took out the old(original) O2 sensor, the little ceramic probe in the tip was in about 7 pieces.

If i had just completed a severe build on my engine and it held up to that high of a rev, i'd be like, "**** yeah", but when this happened i almost **** my pants. I'm not looking for any props for having an engine that revved that high and lived, all the props go to honda. most cars don't even operate after 180,000 miles, and mine just hit motorcycle territory. Another reason i'll always drive one.

but back to the problem. i'm gonna order a new EACV from honda today, and if that doesn't fix it, oh well, at least my EACV will be new. I'm also getting a Snap-On Compression/LeakDown Tester when i get to work. I'll let you guys know the results later. Thanks
Shawn

 

You are splitting hairs there buddy. So what if it only went to 10,500. Maybe it went to 12,500! Big deal. All he knows for sure is that he over revved the crap out of it. Get a life!

 

werd!
i can't wait til after work when i can do a comp. test on her. it runs better since i pulled the IM and cleaned it than even before i over-revved it. i'm really thinking i didn't bend any valves. runs great, and no ticking/knocking. damn honda, this engine should be splattered all over I59...... I'll never have a reason to do a swap.

 

i know!! geese. like i said in my original post, i just wanted to know how he got the number!! i don't care and i hope nothing is wrong with your car, but i just wanted to know!! haha.

 

Ok man, tomorrow i will drive my kaa at different speeds in 2nd, and figure out exactly what speed my engine was revved up to. just to make you happy. i missed the Snap-On guy today, not even sure if he showed up. I'll figure this damn thing out sooner or later. Oh well
I think this damn thread has turned into more of a headache than my car.

 

You said it does the irratic idle after the car warms up right? If so that sound like the iacv to me

 

I think that since the car is warming up, the mixture is rich, and the IACV keeps the idle high to get the motor warmed up. Once the motor is up to operating temp, the IACV does next to nothing (just keeps the idle steady when the A/C comes on, or lights or wipers or interior fan, rad fan, etc...). With the possibility that bent valves are too much for the IACV. Just my opinion, and I hope I'm wrong, but the compression test will be the proof.

 

well, when the throttle is closed, i'm pretty sure that the EACV (Electronic Air Control Valve, the old-school Idle Air Control Valve) is what keeps the idle steady (air has to come from somewhere). I'm really thinkin that this is what is bad, but yeah, the compression/leakdown test will tell the truth.

 

Okay guys- the hater results are in. my car does exactly 8.5 mph per 1000rpm in 2nd gear (17 @ 2000, 34 @ 4000, 51 @ 6000, i am basing these #s on readings from my stock gauges). I was doing exactly 90 at fuel cut in 3rd when i "downshifted". my engine hit exactly 10,600 rpm. sorry to dissappoint you for lying. i figured more ~11,000. hate me for lying to you. i'm a horrible person. O'Doyle rules!! i mean, Honda Rules!! Honda Rules!!