Johnny_law

I need some advise where to look to fix an issue that became apparent after a weeping power steering hose replacement (Thanks Overboosted28 for a well documented DIY). I believe my symptoms may possibly not be associated with the P/S hose replacement.

I have to give you a bit a history to get you up to speed on where I am. About a month ago I had a get together and a drive on a gorgeous Saturday morning. After about 100 miles on a semi-spirited drive, I was mildly shifting from 2nd to 3rd and noticed a strange stumble or oddity. In my mind I thought that wasn't normal. It lasted less than a second. About 10min later I had a check engine light. I pulled off and stopped at a local auto parts store nearby and borrowed their code reader. It read OBDii code 1140 "Load Detection".

I cleared the code and drove home never going on boost from that point. Probably a 30 mile drive on a freeway. Anyway the car ran fine but I thought I heard a bit of a sucking sound when I had the window open. So I suspected a loose boost hose connection. Car was idling just fine at the time.

When I got home I checked the connections at the intercooler and the turbos. Everything was tight. I removed the intercooler and then proceeded to remove the rear bumper as I hadn't done that yet and also anticipated replacing the P/S hose. No worries about leaning against the bumper and/or spilling pentosin on it either.

One thing led to another with the kids going back to school so the car sat on my lift with towels covering the throttle body and the top of the boost hoses.

So Saturday I replaced the P/S hose. In order to do that I had to disconnect the fuel filter and I did remove the plug boot next to the passenger side boost hose as I had to remove the hose for access.

When I buttoned everything back up I placed the passenger boost hose back first then wedged the plug boot back into the socket. It's a tight fit, but done. I've done this before. After everything was back together, I fired up the car and it started and quickly died. Huh? So I though maybe air from the fuel filter was giving me some problems. So tried again. Same thing over and over. So I figured it couldn't be fuel, so I thought that the plug wire maybe wasn't snapped on the plug. So I removed the passenger boost hose and reset the plug wire on the sparkplug. I then got some dishwashing soap and reinstalled the boost hose. At this point I started the car without the intercooler and all was great. It idled just fine.

So I put everything back together again and once again the car will start for a second then stall. Huh? So I loosened the 3 bolts holding the intercooler to the throttle body and the two bolts holding the intercooler to the fan shroud and wedged a piece of wood to leave a bit of a gap between the intercooler and the throttle body. I started the car and everything was fine. As soon as the intercooler seals to the throttle body it would starve of air and die. Huh?

So I removed the intercooler again and started the car. As it was idling, I cupped my hands over the top of the boost hoses and the car stalled. Not knowing how air is controlled between idle and boosted. Now I'm suspecting a loose hose or a bad valve but really don't know where or what to look at. Everything behind the engine I can see (and that is not much) or feel (via braille) seems hooked up. All connectors to the Idle control valve, MAP and the intercooler when installed are connected.

Any advise on where to concentrate my efforts. I did search but didn't see anything.

Thanks in advance,

Johnny

OverBoosted28

Are you sure the plug on the ISV, & intercooler temp sensor are both plugged in completely? Make sure nothing is interfering with the throttle butterfly. Strange that it'll run fine w/o intercooler but stalls once you install it. Don't think fuel delivery is your problem. Possible vacuum hose got disconnected during the work. It'll be something simple once you find it. Unfortunately, there's a mess of hoses that can easily come loose, down behind everything. Look at the PET and see what lines go where and try to chase them (via braille) to make sure they're all connected. Good luck.

Johnny_law

Thanks Overboosted28,

Yes I am sure all electrical connections are connected and secure. Everything is clean. It probably is something simple. My only concern is the Check Engine light came on even though it seemed to run fine.

If I understood the air flow in these machines It might make it easier to diagnose.

I know that air is always passing by MAF through the air filter. But under idle does the airflow always run through the turbocharger-intercooler or does it by-pass it through the hoses connected to the throttle body via the idle control valve. Obviously under boost air is being inducted into the throttle body via the intercooler. If I am correct that air flow is different between idle and on boost what changes that?

It seems that there is a suction on the boost hoses when idling without the intercooler. Seems odd to me.

OverBoosted28

My understanding (which may or may not be correct) is that all of the air that goes into the engine still passes completely through the same system. Airbox, MAF, plenum/air tubes to turbos, intercooler hoses, intercooler, throttle body, intake runners then cylinders. It acts as a NA car w/o any boost. The only bypass should be excess boost being "blown off" to avoid slowing the incoming charged air. With my old ISV hose blowing off on boost tells me that the ISV just regulates the idle to its needed ratio when on boost or under vacuum. Your system is pretty much always under vacuum when it's not under boost. Not sure if there's ever ambient pressure. I really think vacuum is leaking somewhere.

Study this and see if you can chase all of these connections down, to assure there tight.

Basal Skull

that's really odd. I wouldn't expect the car to idle 'fine' without the intercooler. I've done it in the past and it would barely run.

Johnny_law

Interesting. My plan of attack today is to print out the PET and mark every connection I can verify by Braille. Then disconnect the battery and reset the ECU.

If that doesn't do it, then remove and clean the IiCV idle control valve.

If that fails O guess it is time to call the flatbed...

Arrghhh!

OverBoosted28

Here's some more detail of the small vacuum lines

OverBoosted28

Don't see it being an issue you can't resolve. Another thought, use some electronic cleaner and spray all connections (male/female) that you messed with. I also put dielectric grease on just about every connection to assure contact. Wish I was close to help

Johnny_law

Good news, I found a loose hose. It is 32 on the PET but the end buried in the engine.

Now to get it reconnected. I suspect it won't be easy.

Johnny

OverBoosted28

32 on the pass blow off valve? All of my hoses that connect the blow offs and the isv were toast. The ends would not tighten. The rubber was basically compressed, hard and non-compliant. Check my post on these. I yanked all of them and went to parts store and matched with thick heater type hoses. Took a little work, but have not blown another hoses since.

OverBoosted28

Also, the 3 ends that connect at the base of the plenum have short brass nipples they attach to. It's smooth brass with a tiny lip. The old hose doesn't want to stay on.

OverBoosted28

Found the pics. Look at the ends of the old hoses
ATTACH]875669[/ATTACH]

OverBoosted28

OverBoosted28

Johnny_law

Well looks like I need to order another little hose. It is beginning to deteriorate at the end near the engine.

I'll try to reconnect so I get good at replacing. I needed to remove the MAF housing which gives me a bit of room, but getting the clamp on in the right place will be difficult.

Any words of wisdom?

Johnny