PCV problems

hankmeister

New Member
5+ Year Member
Hi all, first post here, looking for some help.

Had some problems with my '90 Civic. As background, I bought it used about a year ago. Has 186,000 miles plus on it. After purchase, I'd get a CEL once i awhile. Then it got worse and worse, and one morning the car wouldn't start at all. Had to get it towed to the local mechanic, where it promptly started and ran fine.

So, the problem slowly came back...CEL would come on, at various speeds/weather conditions, but usually when I would take my foot off the gas and be coasting.

SO - one morning a radiator hose blew, froze the water pump, and broke the timing belt. When the local mechanic replaced all the necessary stuff, the CEL was back with a vengance. In his troubeshooting, he found the PCV clogged. He cleaned it out, and it's worked fine for about 3 months now.

So, it started again. Random CEL. I had the mechanic show me where the PCV valve is, and I swapped it out with a new one. Now, I get the light almost immediately after start. Car seems to run fairly well, just a bit of a flat spot when shifting from 1st to 2nd (4 speed manual).

The hose coming up from the breather box to the PCV valve seems to be fairly dried out...tried trimming some of the worst off, but I'm thinking I may still have a vacuum leak there, causing the check engine light? If so, where's a good place to p/u a replacement hose? A quick search of the net doesn't turn up a lot as far as PCV accessories, other than the valve itself.

Whew...long winded, but wanted to give a good background of what's going on. Hope somebody can help!

best
Hank
 
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RonJ

Banned
I don't understand your complete focus on the PCV valve. Pull the carpet back and tell us what trouble codes are blinking from the LED on the ECU:



When done, clear the codes from the ECU and drive the car to see what codes repeat.
 


hankmeister

New Member
5+ Year Member
Ooops, forgot about that...I believe it was/is 7 & 16, dealing with fuel injection and I forget what else. The mechanic at the garage had double checked those also, and was working on troubleshooting those when he found the clogged PCV valve.

At the time, cleaning that out seemed to do the trick...plus due to the fact that after putting in a new one today with the rotted hose, and getting an immediate (within 5 seconds of engine start, something it never did before) CEL, it seems to be a prime culprit.

Let me go double check, and post what codes I've got currently.

best
Hank
 
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RonJ

Banned
After you have written down the codes, remove the Hazard fuse in the main relay box for a few minutes to clear the ECU. Then drive the car to see which codes repeat. Only repeated codes should be pursued.
 


hankmeister

New Member
5+ Year Member
Right now the only code I'm getting is 7. By the "hazard" fuse, you mean the fuse for the warning/hazard lights under the left side of the steering column, correct? I've also read somewhere I can also disconnect the battery for a couple of minutes to clear it?

thanks
Hank
 

hankmeister

New Member
5+ Year Member
One more piece of info...when I start the car, if I keep the idle up from the get-go, the CEL doesn't click on. HOwever, if I let the idle go down to normal (high vacuum state) on pops the light.

I'm going to r2 the PCV hose tomorrow, see what that does for me....

best
Hank
 

RonJ

Banned
One more piece of info...when I start the car, if I keep the idle up from the get-go, the CEL doesn't click on. HOwever, if I let the idle go down to normal (high vacuum state) on pops the light.

I'm going to r2 the PCV hose tomorrow, see what that does for me....

best
Hank
CEL code 7 tells you to spend more time troubleshooting the throttle angle sensor (TPS) on the throttle body than the PCV hose.

The hazard fuse is located in the main fuse box under the hood.
 

Ken @ strumholl

New Member
5+ Year Member
Cel 7

I had a problem with the CEL7 and found that the sensor can not be replace without drilling out screws. My mechanic cleaned the sensor through the throttle body and that problem has not returned after 2 years.
I also recently noticed a dried out pcv hose and can't seem to find a replacement online. Anyone know what to use for that?
 

hankmeister

New Member
5+ Year Member
HI Ken, thanks for the feedback. I had no luck searching for PCV line online either.

My CEL has gone back into remission...hasn't been on for a couple days (knock wood) even though I haven't gotten around to changing the hose.

I'll definitely get with my mechanic about the Throttle angle. Thanks for the tip!

best
Hank
 

hankmeister

New Member
5+ Year Member
Quick follow up

Just a quick follow up...after rem'ing/repl'ing the PCV, and getting the hose taken care of, I don't seem to be having any more CEL's. Just want to say thanks to those who offered up help, and I'm sure sooner or later I'll be back asking for your assistance again.

Thanks much,
Hank
 

RonJ

Banned
Your PCV valve and hose may have needed to be replaced, but this would not have thrown code 7.
 


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