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Discussion Starter #1
Well a few weeks back I got a CEL for rich fuel mixture that went away and came back twice. Now it is back to stay and the car is noticeably driving very badly.

Today I was boosting into the red (2001 9-3 base, no mods), but it felt like I was barely boosting at all. I floored her in 3rd out of frustration to see what would happen and BANG, followed by engine failure! It took a bit to realize what had happened but the air delivery pipe just behind the plastic engine cover had popped off and cracked the plastic cover in the process. Ok so no biggie, I put it back on and clamped it down real tight. I was actually happy about it, thinking that it must have been somewhat loose all along, and thus i was losing some of that pressure and getting bad performance and was running rich from the lack of air. Well that was wrong...

Now it is boosting normally but I dont feel the power at the peak of the powerband. The engine revs normally, the turbo gauge goes up to its normal postion in the yellow, but I am not accelerating very well at all, and acceleration kind of yo-yo's up and down, instead of a nice smooth power curve.. If I then floor it and try to get more power out of it, acceleration will ramp up then back off sharply followed by some strange rapid clacking noise :eek:!

If i drive like a grandma everything seems to be ok except when on my way home from this testing, at a stop light it started idling very very hard as if it was going to die, then resumed normalcy, then went rough again, then normal, then fine until I got home.

Any ideas? If not hopefully i can have it looked at by a professional tomorrow. I really need the car right now though. At the moment I am keeping her grounded :(.
 

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Discussion Starter #2
update

well i had the codes read at Autozone. I had 4 codes in there total, the exact numbers I cannot tell you. I had the guy clear them out too soon not thinking.

codes were:
rich fuel mixture
Ignition system fault x2
MAF or VAF sensor (never heard of VAF)

I had them cleared out so I can see what pops up next. I am sure some of those were the direct result of my air delivery pipe jumping off while driving 50mph. I also noticed the bolts holding the DI down were very loose and out maybe 1/3rd the way. I used some threadlocker on them. The ignition codes scare me, the nuts were loose, but the DI pretty much suctions itself on there fairly tight to begin with.

I am running autolites instead of NGK's (too lazy to order stuff), and I will be swapping them out asap. The car still runs terrible though after securing the DI and air delivery pipe. at idle the engine seems to pulse vibrations up and down, not the steady slight cowl vibration I am used to. Accelerating any more than a grandma scares me and I feel like the engine might die, it hesitates and has very poor acceleration when pushed, definately telling me not to push that pedal down hard at all (.

From my guess I might have a bad DI, crappy plugs and a possible bad MAF. or the MAF code is possibly just from the delivery pipe flying off? I have had a rich fuel mixture code intermittent for about 6 weeks total now though and its here to stay this time i think.

any advice?
 

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Discussion Starter #3
update2

I just took the 9-3 out for about 45 minutes on the back roads so i could test out acceleration. No CEL has come back since they were cleared earlier today. Driving is still bad. If I accelerate moderately hard the turbo needle goes up normally, the RPM's go up normally, but the car jumps forward and eases off then jumps forward and eases off all through the power band in each gear. The guages show nrmalcy, but meanwhile I am pushed forward against my shoulder harness then shoved back in my seat at about 1 second intervals. no CEL yet :cry:

Pedal to the floor at peak boost I sometimes head a fluttering/clacking noise from somewhere in the engine bay...
 

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If I accelerate moderately hard the turbo needle goes up normally, the RPM's go up normally, but the car jumps forward and eases off then jumps forward and eases off all through the power band in each gear. The guages show nrmalcy, but meanwhile I am pushed forward against my shoulder harness then shoved back in my seat at about 1 second intervals.
BPC valve: This sounds like overboost/fuel-cut in rapid succession. On my car, this was caused by a dirty BPC solenoid valve, the one that controls the turbo waste gate.

Once diagnosed, a mechanic blew it out with compressed air, reinstalled it, test drove the car, gave me instructions to clean it out once a year, all in less than one hour. I asked about a new valve, and his comment was basically that I could either plan on a can of dry air once per year, or a new part for $200 about as often, my choice.

Charge Air Bypass Valve: Some of your other symptoms sound like a leak in the vacuum line which operates the diaphram in the turbo bypass valve. This is a long hose exposed to a lot of engine heat (I replaced mine twice so far).

If the hose does not hold vacuum, the boost pressure has no place to go when the throttle plate slams shut while shifting gears, it builds up in the so-called "charge-air" pipe, and the back pressure acts as a brake on the compressor fan of the turbo. The turbo slows down, and when the transmission drops into gear and the ecu calls for boost because the throttle opens again, you have no power, because it takes some time for the turbo to spin up to the speed required to make pressure...

DIC & Plugs: As for the DI cassette and plugs, the rubber boots that go over the plugs have to be greased with dialectric grease, and fit tight. Some of my rough running issues were fixed this winter when we found completely dry boots at the DIC. I ran a couple tanks with an injector cleaner and regapped at the same time.
 

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How much grease should you put on? And do u put in the rubber things or on the plug? How often do you guys change your plug. Is bpc valve the one close to the radiator?
 

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Discussion Starter #7
giving it all a try

Well the DIC boots are nice and greased with dielectric, and i put a dab on the end of each plug where they meet the boots.

I will clean out the BPC with compressed air and replace the vac line and see what happens! Still have til monday before i can even call a garage to look at it, so will try what I can. If this doesnt work I will see if I can get my hands on some NGK plugs. It has autolites at the moment, but I can't imagine they would cause such severe problems. From my understanding they may not detect knock right because of blah blah blah ...you have to use NGK cuz I said so.

Still wondering what caused the air delivery pipe to build up so much pressure it burst off.
 

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Squoosh! said:
Still wondering what caused the air delivery pipe to build up so much pressure it burst off.
When you accelerate, and then take you foot off the gas, like you normally would when you shift, the throttle plate slams shut while the turbo is still spinning and making boost. Vacuum develops UNDER the throttle plate because the engine is still sucking air. Pressure builds ABOVE the plate until the bypass valve opens, or the turbo compressor slows down.

The vac line to the bypass valve goes from positive pressure to vacuum (it is attached to a cavity in the throttle body which is UNDER the throttle plate, and connects to the intake manifold - NOT directly to the throttle barrel) The vacuum in the hose opens the bypass valve and relieves the pressure build up between the compressor and the throttle plate...

...what I was suggesting above was that IF the bypass valve was not doing its job for whatever reason (bad valve or cracked vac line, or something else), pressure would spike in the delivery pipe. The plastic pipe is not designed to hold that!

On the ng900 one of the IC hoses would probably blow off first, but in your case, it turned out to be the delivery pipe.

To see this you would need a boost pressure gauge attached above, not below the throttle plate.
 

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Discussion Starter #9 (Edited)
ok how do i tell if it is broken?

Ok i replaced the plugs and the vac lines, and I have the BPC valve off now. How do I tell if this thing is broken or not? It takes a lot of effort to push the diaphraghm back, I cant believe it requires so much pressure.

I dont see anything that needs blowing out really. It is completely clean inside. I can't imagine my inatke or IC being very dirty.

You were talking about the BPC. This is the turbo bypass valve I am holding in my hand here, a thing commonly replaced by forge products. Are we talking about the same thing?
 

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Two different things. "charge air bypass valve", see p/n 4441895, "boost pressure control valve", p/n 7485576. See pics on saabsite.com or Europarts, search by part number if linking the pics below does not work.

The bypass valve can be tested by applying vacuum (suction), to the nipple that the vacuum hose attaches to. It should just start to open at 4-6 inches Hg pressure, and full open at 16-18 inches (for the stock one)



The BPC, below, was cleaned just by blowing compressed air into the three ports, carefully. The mechanic used shop air, but said a can of dry air from any office supply should work. I do not know how to test it, there may be a procedure in the WIS.

 

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Discussion Starter #11
neato

ah great!

Not by my car at the moment but I think that doohickey in the second picture has 3 hoses which connect to or are near the MAF just right of the air filter? Bleh I will go check in the dark and try to yoink it out and hit it with a hammer a few times or something =) j/k !

Thanks for the help, lets see if this is the puppy that peed on the rug.
 

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Discussion Starter #12
hmm what i described i pulled and cleaned but it wasnt dirty, it looks slightly different than the picture though, guess the scavenger hunt continues!
 

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Discussion Starter #13
hmm did'nt work, was worth a shot

replaced some of the vac lines, replaced plugs, regreased booties, cleaned BPV and BPC. Seems to run better but power is still lacking, hesitation pulsing isnt there anymore, just not getting much boost. THis is especially noticeable in 3rd 4th and most of all 5th. flooring it in 5th at 70mph doesnt feel much stronger than a chevy cavelier.
 

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Did you actually blow out the BPC? I would have bet on that fixing part of the problem, but maybe the "hesitation pulsing" and the lack of power are two different things.

No leaks from the vacuum lines or the hose from the throttle body to the evap canister purge valve, or the hose to the FPR which is mostly hidden?

I am assuming you have new plugs, some concentrated injector cleaner has been run in the gas, premium gas in the tank, and so on... and you are back to looking for something causing a rich fuel mixture?
 

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Discussion Starter #15 (Edited)
yeah I did blow out the BPC. Maybe the air can did not have enough pressure in it but nada came out of it. It was completely clean. My BPC looks slightly diffeent than the one in the picture, but that is just due to a diff engine model. On the Saabsite mine also only costs 60 dollars where yours costs 200... ouch.

And yep, I always run premium fuel, and toss in a botle of techron about twice a year. Full synthetic oiil changes every 4k.

I havnet taken the car out and pushed it really hard, but a short test drive up and down the freeway showed me that power isnt being delivered in sharp pulses. Its even, just maybe 30% of it is missing.

I don't know where the FPR or evap canister purge valve is to check the hoses... still learning here

Still no CEL has returned btw, gonna keep troubleshooting and drive it the way it is til I get a CEl i spose. Rich fuel mixture is bound to come back.
 

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The fact that everything seems clean is a good sign. Most every hose and valve I looked at on my car had some oil residue or other dirt in it.

The hose from the evap canister purge valve enters the throttle body at an angle, from the direction of the passenger side corner of the engine bay. That hose is not a true vacuum line, bacause it carries gas fumes to the intake to be burned.

The other vacuum lines and PCV hoses hoses are identified and described at the link below, including pics. I used part numbers for the ng900, because that is what I have, so those will not necessarily apply to your car. The FPR hose gave me some trouble, you can't really see it to inspect it until you pull it out.

http://www.geocities.com/ng900set//Vac_hoses/vac_hose.html

Good luck.
 

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Discussion Starter #17
may have found something.

I can't see the item i am looking for in any of the pictures you posted but I found a hose that looks pretty chewed up. It is the top hose coming out of the BPC (marked "R") which snakes downward and attaches to the air intake, this hose also has a splice off of it which goes upward and snakes around the valve cover and attaches I think to the throttle body. Where this hose meets the air intake it is all chewed up and cracked. I can't get a better look at it without burning my face off at the moment. Kind of a difficult place to get access to with a hot engine, the hose may be split up the side. It is crimped at a hard angle and where it meets the intake the sides are split in several places. Hopefully I will get a chance tp pull if off later tonight to see if I can cut and reattach, or figure out where to get a new line.

keep up the good work PMI =P You are saving me lots of money so far, lol thanks =)!
 

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Thx, glad you are getting something useful out of all this, <chuckle>.

Squoosh! said:
I can't see the item i am looking for in any of the pictures you posted but I found a hose that looks pretty chewed up. It is the top hose coming out of the BPC (marked "R") which snakes downward and attaches to the air intake, this hose also has a splice off of it which goes upward and snakes around the valve cover and attaches I think to the throttle body.
I think you are describing two separate lines, connected to the air intake close together, but on my car not branching off, just near each other.

The BPC valve has three hoses, if any one of them has a crack to the point of being open, it will screw up the way the turbo works. You may have found the problem, the wastegate is probably opening too soon, so you are not getting the boost you should be. At the same time, the ecu is supplying fuel as if the boost pressure was there, so... too much fuel for the amount of air getting in... engine running rich.

I think they are 6-mm inside diameter hoses, not 100% sure. The one to the intake can probably just be taped over temporarily, but not for long, because of the heat. They are marked as follows:

W: wastegate
R: air intake pipe
C: turbocharger

Don't mix them up, marking them with a pice of tape can save a lot of trouble (don't even ask ;oops: ).

The other line is part of the crankcase ventilation system. Whent he engine is on boost, the check valve (PCV valve) is closed, and the valve cover is vented using the vacuum made by the turbo in the intake. In other words, the turbo sucks the engine fumes into the intake through that line.
 

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Discussion Starter #19
I am going to have to miniaturize my hands to get to that hose i think. Wish i could post a picture but all i have is a camera phone (.
 

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Discussion Starter #20
Yick !

alrighty tackled those vac lines today. Hose R was indeed the one which was spliced off and snaked around the valve cover to the TB area. The hose which came directly off of R and went down in a sharp elbow bend to a nozzle on the air intake was in fine shape, just not outwardly so.

So thus far, I have replaced all the vac lines that looked worn, replaced the plugs, regreased DI and torqued it down with loctite. I still must be losing vacuum somewhere. Turbo will beleageredly come on to about half in the yellow and today I noticed it actually dips back down and comes back up along with the acceleration surging. Mybe surgeing isnt the right word. I am not gettign any kind of overboost, my boost flat out sucks. I am getting lame boost accompanied by boost loss.

When I accelerate hard turbo needle barely comes hits the end of the white. If I floor it and hold it for a while I can get a bit of yellow accompanied by the dips and boost loss. Another thing I noticed is that as soon as i let up on the throttle just a little bit, all my boost is completely INSTANTLY gone.

Maybe my wastegate is not completely cllsing and opening wider? Just a retarded idea from a novice. Maybe its time to hit the dealer up.
 
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