Is the Intake Man Cover ever responsible ...

[Jehu]

Part #3 , for a loss over overall power? Feeling less kick when hitting the gaspedla and trying to cover any and all bases I am myself able to check and possibly replace before I bring her in to the Indy. saw this in another thread but the symptom IIRC was described as misfiring and hesitation.. I have had several isolated instances of this but the more persistant and pervasive condition is the gas pedal hitting the floor with less response. Used to launch or lay rubber but while it doesn't really bog ( unless i'm in much to high a gear) it's just not as responsive... I assume I could replace such things as this, the throttle body gasket, the intake manifold gaskets and of course O2 Sensors, spark plugs, and coil boots if neccesary with no problem. Am I overlooking some potential issue that I might also myself be able to fix? What are the chances i have blocked cats or the muffler is clogged or obstructed?

http://home.comcast.net/~cpkver8/images/3.png

[jofusfarr]

Get some carb cleaner or engine starting fluid...spray it, while idling, around the base of the intake manifold, the back plate, and at the throttle body joint. Additionally, spray around the hoses that come from the TB - to the brake booster and the charcoal canister. Spray all over and listen.

(If you need to know what to hear for, spray some near the intake filter assembly, right headlight. You'll hear the difference)

If idle changes, you've an air leak of some kind. Isolate it further by using the spray.

If you can't find a leak, check fuel pressure to start.

Hesitation and misfire = fuel/air problems...

Report back and I'll help you figure it out (I've a 540iA, myself)

[RallyD]

Jehu
inspect the intake hose that runs from airbox to throttle. Mine looked fine but was split around the bellows and was allowing unmetered air to enter the engine. This caused sluggish response and was an easy fix. Because this potential leak is in front of the throttle there wouldn't be any issues with idle.

Typically the computer ignores o2 sensor signals under WOT conditions.
Ever change the fuel filter?

When looking for leaks on my turbo car I remove the air filter and connect a pvc plastic pipe cap to the intake pipe. The pvc cap has an air compressor fitting that allows me to pressurize the intake manifold and find leaks by ear or with some soapy water in spray bottle.
looks something like this http://img213.imageshack.us/img213/5405/boostietest7ag.jpg

[Jehu]

Jehu
inspect the intake hose that runs from airbox to throttle. Mine looked fine but was split around the bellows and was allowing unmetered air to enter the engine. This caused sluggish response and was an easy fix. Because this potential leak is in front of the throttle there wouldn't be any issues with idle.

Typically the computer ignores o2 sensor signals under WOT conditions.
Ever change the fuel filter?

When looking for leaks on my turbo car I remove the air filter and connect a pvc plastic pipe cap to the intake pipe. The pvc cap has an air compressor fitting that allows me to pressurize the intake manifold and find leaks by ear or with some soapy water in spray bottle.
looks something like this http://img213.imageshack.us/img213/5405/boostietest7ag.jpg

I changed the fuel filters last week,no change.
I will inspect the bellows more closely.

I have been thinking i can hear some sort of air rushing sound from under the hood which i don't recall hearing all along so thanks for the ideas!

[Jehu]

Get some carb cleaner or engine starting fluid...spray it, while idling, around the base of the intake manifold, the back plate, and at the throttle body joint. Additionally, spray around the hoses that come from the TB - to the brake booster and the charcoal canister. Spray all over and listen.

(If you need to know what to hear for, spray some near the intake filter assembly, right headlight. You'll hear the difference)

If idle changes, you've an air leak of some kind. Isolate it further by using the spray.

If you can't find a leak, check fuel pressure to start.

Hesitation and misfire = fuel/air problems...

Report back and I'll help you figure it out (I've a 540iA, myself)

Thanks for the insight. I'll see what i can find.

[Jehu]

Maybe this will illustrate my issue


http://home.comcast.net/~cpkver8/images/PICT0002a.MOV

[ahlem]

I'd vote for fuel pressure or dirty injectors. Is the Fuel pump original?

[Jehu]

I'd vote for fuel pressure or dirty injectors. Is the Fuel pump original?

As far as I know the fuel pump is original. 234,xxx on the Odo.. I have used various fuel injector cleaners fairly frequently from Red Line, Lucas Oil and just today a Can of Sea Foam... Can the fuel pressure be easily tested?

[MBXB]

When was your last Inspection II?

[Jehu]

When was your last Inspection II?

LOL...bwaahaha... are you kidding?? Who does those on old cars like these?// I don't have the kind of disposable income to spend $ 700 or whatever just to find problems.. that's why I come here,lol... please my chest is hurting ...lol... Inspection II... you're killing me...

[MBXB]

LOL Just thought I'd ask...
I concur with the other guys.. check for intake leaks; check any rubber hose that goes to/from the intake manifold.

There's a small hose (#6)
http://www.realoem.com/bmw/showparts.do?model=HE53&mospid=47410&btnr=13_0385&hg=13&fg=15
It goes from vacuum to the fuel pressure regulator.

[Jehu]

LOL Just thought I'd ask...
I concur with the other guys.. check for intake leaks; check any rubber hose that goes to/from the intake manifold.

There's a small hose (#6)
http://www.realoem.com/bmw/showparts.do?model=HE53&mospid=47410&btnr=13_0385&hg=13&fg=15
It goes from vacuum to the fuel pressure regulator.

Thanks very much for the ideas.. I do appreciate any help.

As for #6 ,would I not be smelling gasoline if that were either off or cracked and leaking? or is the positive pressure so much and constant no fuel ever reaches it.

[MBXB]

It's a vacuum between the PVC plate and the fuel pressure regulator, so you wouldnt smell any gas.


http://inlinethumb46.webshots.com/41645/2815242630047009931S600x600Q85.jpg



Thanks very much for the ideas.. I do appreciate any help.

As for #6 ,would I not be smelling gasoline if that were either off or cracked and leaking? or is the positive pressure so much and constant no fuel ever reaches it.

[Jehu]

OK. While I have your attention mind telling me what size Torx drive I need to remove the Intake man if i want to do that? I'm actually seeing slightly better MPG after a can of Sea Foam in the Tank yesterday which is encouraging. Maybe this weekened I'll be able to look at things closely.

[MBXB]

http://www.bimmernut.com/forum/showthread.php?t=1142