When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I'm currently at work and since I have loads of down time, I decided I was going to remove the PCV valve and use some compressed air to give it a cleaning. As I was removing the hose from the valve itself, the other end of the hose broke off of where it's attached (I think it's attached to the EGR) due to dry rot.
Couple things;
I have a slight hesitation that I was trying to fix by removing the PCV and now that I come to think of it, this hose may have been broken the whole time. I did try to start the car after breaking the hose and it fired right up as usual (haven't driven it since my shift isn't over yet) but I'm hoping I'm able to make it home without issue.
My question is this....does anyone know whether a broken or disconnected PCV would cause the famous hesitation issues we've all been chasing? Are there any adverse effects to this hose not being properly connected? As usual, my hesitation happens under light - medium throttle, usually after the car has been driving for atleast 10-20 minutes. Car idles PERFECTLY 100% of the time and runs LIKE A CHAMP on cold startup. Power at the slightest touch of the throttle.
Things I'm changing soon: Driveshaft center support bearing (could this be causing the hesitation???? I already know it's bad)
Transmission mount (or maybe this???)
Also, does anyone have a part number for the hose?? Nvm, evidently AutoZone sells PCV hose by the foot.
Edit 2: Drove home fine. It hiccuped a few times closer towards the end of the drive as usual. Going to replace this hose in the morning and probably try to get a replacement pcv valve.
yes it lets in unmetered air into the engine with a cracked hose, same with leaky valvecovergaskets. the ecu tries to adjust and causes random hesitations.. just replace with normal pcv hose, its probably like a 3/8" but take it with you and get some new worm clams for both sides.
reset the ecu first, pull the efi fuse and give it a chance to re-learn. its possible you just have other leaks/issues.
unplugging maf puts it in open loop where it ignores everything but rpm and coolant sensor, so that doesn't mean your maf is bad.
how about the year of the car.... assuming its a sc400. how many miles?? have you ever changed the o2 sensors?
the fact that it happens when warm makes me think o2 sensors are super old and lazy now.
there is also a hose on the other valvecover that goes to the intake piping, make sure its good also or it lets in unmetered air. what about valvecover gaskets.. any oil dripping down?
I bought a remanufactured ECU from Darryl Geller a few months back and replaced the EFI fuse just a few months before that.
It's a 95 SC400. 169xxx. I've never changed the O2 sensors. No oil leaks from the valve cover gaskets. But this is the current state of the intake piping. Had a nail in there before but I don't think it was doing as good a job.
I went ahead and reset the ECU. I'll take it for a drive.
Car continued to drive extremely well last night. Not a single hiccup.
This morning, it fired right up and proceeded to go from 1st to 2nd to 3rd gear without slipping like it usually does. Normally in the morning once I get up to 3rd gear once, it drives normal. This time it was normal from jump street. I don't know but unplugging the MAF has this thing running wonderfully. I have a used/new to me MAF on the way so we'll see.
I received the MAF this morning and plugged it in. Nothing. Same crappy running and now I get a check engine light on with it plugged in (which I wasn't getting before with my old one plugged in). Now if I drive it a few seconds the check engine light will go off and stays off for the most part. But then it comes back on again when I turn the A/C off. I'm getting codes 24 and 31 whether I have the MAF plugged in or not. But when I unplug, the car goes back to driving fine. I've even noticed I've gotten better gas mileage the past few days having it disconnected...
Any insight??
Also, is this supposed to look like this? I don't know if it's off or what but it's something I just notice
d.
your replacement used maf is more shot than your original. pic looks ok except you have a leak somewhere maybe power steering or water pump hard to tell its too zoomed in.
your replacement used maf is more shot than your original. pic looks ok except you have a leak somewhere maybe power steering or water pump hard to tell its too zoomed in.
So that white dot and the 0 aren't supposed to line up? The leak is more than likely the power steering pump. I have to refill that bad boy atleast once a week, week/half.
no thats just a white dot, there is a line on the pulley that lines up when you turn it to line up, it doesn't just stay lined up it spins around you know.
09-16-15, 06:16 PM
So My PCV Valve Hose Broke
that I was trying to fix by removing the PCV and now that I come to think of it, this hose may have been broken the whole time. I did try to start the car after breaking the hose and it fired right up as usual (haven't driven it since my shift isn't over yet) but I'm hoping I'm able to make it home without issue.
