2002 FlexFuel Grumpyness

[locovaca]

The tank is pressurized with vacuum from the engine. There should be a rubber hose that runs from the charcoal canister back to the tank along the same trunk as the fuel lines.

 

[Chazz Layne]

The tank is pressurized with vacuum from the engine. There should be a rubber hose that runs from the charcoal canister back to the tank along the same trunk as the fuel lines.

Rubber hose... check. Vacuum present as expected.



My hesitating start issue is gone now since putting the new pump in (today was the first time it had been sitting long enough to know for sure). The really rough getting worse and worse idle is still there though. Now it gives me a flashing check engine light. I'm unable to pull the codes though, as the OBD computer is not responding anymore... not sure if it is busy or fried (not that there's any reason it should be dead). Putting that aside for a moment...

I moved on to checking the PCV valve. The old one still rattles but is very gunky, so since they are cheap I dropped a new on in. I noticed that it is very loose in the rubber grommet, so much so that if the hose that goes into it wasn't pushing down on it then it would probably fall out. Is this normal?

In following the manual's instructions for testing the replacement (Haynes), I started the truck, let it idle, then went to pull the hose going into the PCV valve to check for vacuum... that's when I noticed that not only is there vacuum, there is so much vacuum that is is jamming the PCV valve shut and quite literally collapsing the hose shut. It is on so tight from the vacuum that I can't pull it off of the PCV valve without first shutting off the truck. I have no idea what that means or where I should be looking next...


I'm waiting with the battery disconnected right now, hoping that post-powerloss I might get the computer into a talkative mood.

 

[fixizin]

First, thanks for the heads-up on the apparent f**kw*ds dba "APWarehouse"... luckily they've never popped to the top of any of my searches... yet.

Secondly, to your truck and PCM (computer), while I can believe that something may have damaged a pin, wire, or entire harness comprising your OBD under-dash connector, I doubt your computer would be "mute" on OBD data flow, but still be running all the real-time engine functions.

Have you tested your OBD-II reader on another -II vehicle?

 

[Chazz Layne]

I double checked the harness/plug/pins, it appers ok. My scanner still works fine on my other truck as well. Yep, I've had it working on this truck before... not sure why it can't connect now.

On a wild guess (since air/fuel/oil are all suspect right now) I checked the oil. I had changed the oil/filter as a first attempt at remedy when this problem originally started to no avail, and have driven it very little since then so it hasn't been due for a check... but I decided to look anyhow. The dipstick was bone dry, despite the fact that the engine has been on for about an hour today.

It took 3.5 quarts to get it back up into the safe zone. I am still trying to figure out where in the heck the little truck managed to hide 3.5 quarts of oil. It hasn't been driven around enough to have lost that much on the road without leaving some sign of the leak underneath, there is no puddle/stain/sign in it's parking spot where it always sits, and the exhaust has always been nice and clean... not that it has been driven enough to burn that much oil in the first place.

I started it up again after topping of the oil hoping things would smooth out, and let it run for a good 20 minutes to get everything good and lubed again, but no such luck. The same extremely rough idle is still present, the hose out of the PCV valve is still under so much vacuum it is pinching itself shut, and the computer still refuses to talk to me (though the CEL isn't on anymore).

 

[bronco_lou]

I'm unable to pull the codes though, as the OBD computer is not responding anymore... not sure if it is busy or fried (not that there's any reason it should be dead).

I have a 2000 chev S10, I put my code reader on it and nothing ( worked fine in my pathfinder) come to find out there is a hot wire on the OBDII plugin port, mine had no power. The fuse was blown for the cig lighter, replaced the fuse and the reader worked fine.

Louis

 

[Chazz Layne]

Been busy so I've been ignoring the truck until today. I checked the spark plugs to make sure they were clean (they are), then double-checked the coolant... which is now the color of Denny's decaf coffee. If I'm not mistaken, that means head gasket?

RAAAR!

 

[joecool85]

Yeah, sounds like a head gasket. Although I've not ever heard of losing all your oil into your coolant before...you don't have a black hole somewhere in the engine, do you? That would explain the vacuum and apparent loss of oil.

 

[Chazz Layne]

I finally got done moving and am now able to work on this again. The Ranger had to help out in the move and did just fine loaded up on a 250 mile trek out here. We had to risk it as my other vehicle was already loaded up with the rest of our stuff. Fortunately, it was all highway miles.

The truck continues to run perfect except for the rough idle. I checked everything in detail and we have lost no oil and the oil is still clean. The coolant still looks like Denny's decaf, but on closer inspection it is just dirty - no sign of oil in it.

I was also able to get the codes to read finally and have only two: P0113 for the IAT sensor and P1504 for the IAC valve. I did try to clean the IAC valve but this only caused total failure and really bad idle so I replaced it. The P1504 code is now gone after replacement and the truck idles better but still not quite like it should.

So all that is left is a slightly rough idle and a P0113 IAT code. Would the dead IAT sensor cause this slightly rough idle? It is really not something I want to replace considering the cost (it is part of the MAF on a 2002 3.0L Flex). Also, aside from the slightly rough idle, anything else driving around with a dead IAT might harm besides MPGs and a little power?