The Chazzer

Hey fellas,
This CRV just can't seem to run right for me for very long. The idle has been messed up for a while now - when I had it in the shop for the burnt valve they told me the idle air control valve needed to be replaced - they had cleaned it but the idle still was bouncy.

So I went and spent the $200 on a new IAC valve, put it in (very easy), and the idle still bounces between 1000 - 1500 rpms.

When the CEL was reset, it stayed off a little while, but when I was sitting at a light idling normally, the idle will suddenly go up to 1500 and bounce around between 1450-1550rpms - it sounds like it's at the rev limiter the way it bounces, CEL comes back on, code is for the IAC valve. I've done this 3 times since changing the IAC valve.

When the AC is on, it generally will stay at about 900rpms and doesn't bounce.

When at idle and it's bouncing, I can hold the brake and let the clutch out to the friction point to bring the idle down. When I release the clutch slowly, the idle will remain normal and won't bounce again until I drive or hit the throttle. Then it bounces again.

I don't know where to check, but it seems like I have a vacuum leak somewhere, but I can't hear anything and don't really know where to check.

My inspection is coming up and I gotta get this thing fixed. Help? Thanks.

The Chazzer

any ideas?

LDForget

vaccume leak.

The Chazzer

Qfactor

RPMS???? thats it.

The Chazzer

OK HERE'S THE QUESTION PUT MORE SIMPLY

Many of you guys know these engines REALLY well. There has to be one or two vacuum lines that tend to crack...or a common problem that affects idle that's NOT the IAC valve.

I'm going to my shop this weekend to try and get this sorted out - it'd really help if someone had some pointers for me before I go.

The Chazzer

nobody, eh?

I bought 5 feet of vacuum line yesterday, I'm going to replace all the vacuum lines I can find, but I need pointers in case there's anything hidden or not obvious.

pointers needed.

Qfactor

check the air assist thermo valve is located on the intake manifold is black in color and one hose goes to the air intake, do this when completely warm up disconnect the hose from the intake that goes the black valve, put your finger on it if, there is vacuum then there is your problem valve not closing as it should, you can replace it or cap it off.

el crapitan

i think you're talking about the fitv. if so, there shouldn't be any vacuum lines running to or from it. it should be bolted directly to the throttlebody. there will be a port inside the throttlebody where bypass air is received by the engine on cold starts.
with the engine at operating temp, remove the intake boot. inside the throttlebody there will be 2 ports. the upper one is for iac. the lower is fitv. engine warm, the fitv port should have very little vacuum. it will have some, but not much. if you cover the port with your finger, and idle smooths out, problem is fitv.
while checking fitv operation, take this opportunity to service the iac port. engine running, use an intake cleaner and spray, with the nozzle tube, liberally into the upper port. snap the throttle a few times while spraying. repeat that a few times. because of the restriction at the end of the port where it meets the iacv, it is inherent to clogging with carbon. this is actually the correct procedure for iac cleaning. the valve never even needs to be removed and the port gets cleaned as well.

another thing you want to check is that the idle is adjusted correctly. an incorrectly set idle will cause the ecm to command the iacv open and closed constantly, causing idle fluctuations. to check; engine warm, disconnect the iacv. idle should be at roughly 500rpm. if not, adjust the idle screw until it is. once 500rpm is reached, reconnect the iacv, clear the code, and idle for 10 minutes to allow any relearn.

also, little known fact: a vacuum leak will not cause a fluctuating idle. if a vacuum leak is detected, the iacv is commanded closed a certain number of counts until target idle of roughly 750rpm is reached. you can actually go outside, start the car, disconnect a vacuum line of your choice, and the idle will sit perfectly still where it normally was.

The Chazzer

what about the fuel pressure regulator? when I unplugged the vacuum line from the intake manifold the EXACT same idle fluctuation occurred but worse than normal. unrelated?

I didn't know about the fast idle thermo valve (had to google it just now) - but if it can cause this sort of problem, it'd definitely worth checking.

does the fitv need to be cleaned like the iac?

will spraying TB cleaner into the iac port hurt my brand new iac valve in any way? s**ts $200, I don't wanna ruin it.

el crapitan

by removing the vac line from the FPR, you're simulating fuel pressure at WOT (no vacuum). it only seems accurate that the problem should be magnified when doing so.
however, that's not to say that it couldn't be the problem.
to test the FPR, you'll need a gauge. install it at the fuel filter. start the vehicle and let it get to operating temp. fuel pressure should be roughly 30-35psi. now, disconnect the vac line at the FPR. fuel pressure should now raise approx. 10psi. if not, either vac line or FPR are at fault. with the vac line removed, snap the throttle 3 times, observing fuel pressure while doing so. fuel pressure should drop by no more than 2psi. any more than that and you have a flow problem. either tired pump or restriction (ie, filter).
that right there is a true dynamic fuel pressure AND flow test.

there are tutorials in the integra forum on servicing the fitv. super easy.
and no, tb cleaner should be just fine. long as it's not soaking in it

The Chazzer

okso, I finally got back over to my shop to test the FITV.

From what I can tell, it doesn't have a FITV. You mentioned an upper port inside the TB for the IACV, and a lower port below it for the FITV. There is no lower port. I looked and felt underneath the TB and did not find a FITV.

Am I retarded or am I just looking in the wrong place, or did I get bad advice? I'm starting to get pissed off.

el crapitan

if you only have one port, you dont have a fitv. some 1st gens have them, some dont. mine does. maybe because its canadian. not sure.
did you service the iac port precisely how id suggested? checked/adjusted idle as per procedure?

The Chazzer

I did clean the port with TB cleaner, cleaned some of the carbon out of the inside of the TB too - didn't help one bit.

I discussed the problem with my service-tech friend - he asked me about the PCV valve. I told him it had passed the blow-test.
He took it out of the valve cover and plugged it with his finger, the idle immediately stabilized. We repeated this 3 times, it worked every time.
I went and spent $2.50 on a PCV valve, put it in...so far so good. We'll see.

It's weird that it passed the blow test but still was apparently faulty.

The Chazzer

yep, it's fixed. all that for a f--king PCV valve that took 30 seconds to change


next up: lowering springs
(one of the front struts/springs is all fubar, so I might as well lower it)

Planning on Tokiko or SenSen front shocks, H&R lowering springs, stock rear shocks.

The Chazzer

so my clutch decided to take a ****
fml