95 525i shutters and loses power at 2500 rpms to 3000 rpms

[caqueenslace]

Hey Pros,
Done a lot of research on your site trying to find the answer. We had multiplee issuess idle problems and such and check engine light. We have lamda code and o2 sensor code.

The car was having an idle problem for awhile and starving for fuel.
Finally one day when accellerating it would shutter starting at 2500 /2800 rpms up to 3000 rpms.

We also had oil in the plugs and a blown gasket.

We replaced the gasket, several coil boots, plugs.

Also new MAF, New fuel pump, new O2 sensor, new fuel filter and I think some other stuff as well.

Got rid of the idle issue and can tell has more power however it still shutters on accelleration once you reach 2500/2800 rpms to 3000 rpm.

It some times acts like it clears out but when you continue to accelerate it goes back into the shuttle.

Often cannot go 65 and if you can get it to clear out it breaks down agan at 75.

Any idea what next? New coils? Could it be the injectors?

Also we clean out the cats too, not more cats.

Let us know.

Thanks,
Denise and Al
;)

[caqueenslace]

No one has anything for us on this issue???
**************************************

Hey Pros,
Done a lot of research on your site trying to find the answer. We had multiplee issuess idle problems and such and check engine light. We have lamda code and o2 sensor code.

The car was having an idle problem for awhile and starving for fuel.
Finally one day when accellerating it would shutter starting at 2500 /2800 rpms up to 3000 rpms.

We also had oil in the plugs and a blown gasket.

We replaced the gasket, several coil boots, plugs.

Also new MAF, New fuel pump, new O2 sensor, new fuel filter and I think some other stuff as well.

Got rid of the idle issue and can tell has more power however it still shutters on accelleration once you reach 2500/2800 rpms to 3000 rpm.

It some times acts like it clears out but when you continue to accelerate it goes back into the shuttle.

Often cannot go 65 and if you can get it to clear out it breaks down agan at 75.

Any idea what next? New coils? Could it be the injectors?

Also we clean out the cats too, not more cats.

Let us know.

Thanks,
Denise and Al
;)

[caqueenslace]

We replaced the complete coils, boots, spark plugs/seals, and the value gasket again.
Reset the computer still missing when it accelerates.

It idles beautiful so it doesn't appear to be an injector issue.

[caqueenslace]

Just pulled the muffler, still doing it. Do we need to unhook the battery to reset the computer after we took this muffler off. After we replaced the coils, we rest battery and drove it. Will the computer still recognize the fix if it is the muffler?

Anybody out there?

I'm miss my car :(

[whiskychaser]

Thought I replied to this so if this is a duplicate my apologies. You will know that oil on plugs means worn valve guides or rings/bores. Any blue smoke? Lambda and O2 sensor are the same depending on which side of the Atlantic you live arent they? What fuel pressure have you got when engine off/running? What inlet vacuum have you got? Have you got any codes now?Is your throttle cable adjusted? - even with all the above you should still be able to get more than 75 mph. Are your brakes running hot?

[caqueenslace]

Thanks for responding!! Appreciate it.

I might have phrased that wrong, no oil on plugs!! had oil in plug holes from gasket blown. Fixed that.

No blue smoke. No check engine light so we should should not have codes. We cleared up the Lamda and o2 sensor codes.

This is what we replaced with brand new parts.

Fuel pump
Fuel filter
O2 sensor
Mass Air Flow
6 coils w/ boots
cats
bosch plugs w/seals
valve gasket
pulled muffler off didn't work

Have fuel pressure but we have not tested it with the car off. should we with the new fuel pump installed?

Have not tested the inlet vacum, will do this.
No codes unless one may show without a check engine light on?
Have not checked the throttle cable adjustment. Was perfect but will check that too.

The car runs perfect at idle and light tippin but hard acceration acts like the timing is off.
How do you check the timing on this car? What advances the timing do you know??

Its got brand new brakes and rotors and they are not running hot.

This is intermitent too. You can get it to 75, 80 but goes through the shutter, sometimes clears out sometimes does not. Runs awesome when clears out. But can't get it past 80 shutters evertime at 79.

Still thinking worn value guides or rings and bores?
With the valve cover off, top part of the engine looks awesome.

Thank you for responding anything else you can offer would be great. We'll get those tests done and report back by tomorrow. Please check back for us.

THANK YOU!!!

[Jon K]

Have you tried the crank position sensor?

[caqueenslace]

No, not yet, should we?

[632 Regal]

cheap part, make sure the gap is correct to the tight side.

No, not yet, should we?

[caqueenslace]

Got one on the way $47 US. Should have it by Tuesday.

We appreciate all your help guys. It can be so frustrating coming this far with all
we have replacement without it fixing it 100%.

We fixed check engine light. New fuel pump did that after we replaced the MAF and O2 sensor.

Car had a few things going on at onces.

Should drive like a dream again once we fix this shutter.

What is that big pipe or should say bomb that goes before the muffler? We couldn't put that back on yesterday when we pulled the muffler. Some pieces are broken on it.

We will right back with results!

THANKS!!

[bloodyvsunday]

in the piping?


The catalac convertor

[paanta]

Weird. After 3000 rpm does it drive fine? Does it pull nicely all the way up the range clear to red line? Is it worse when it's cold or hot? Can it be revved freely through the bad range if the car is in neutral?

If it runs fine above and below that narrow 500 rpm band, it's probably a sensor or something electrical fritzing out rather than one of the bigger bits, since it can get enough fuel and provide enough spark under most circumstances.

Have you checked the silly stuff like the battery/alternator, grounds, etc?

[caqueenslace]

Hey Folks!!!! GREAT news! The crank position sensor fixed it!!!!!!

My husband kept going back to the timing not advancing when you accelerated hard.

Wires were hardend and shrunken up at the ends of the connectors. Drives like a dream again.

Thank You and Take care until next repair.

[caqueenslace]

One more question before we move past this repair. Took it out for the second test drive, second start up and it had a long crank before it started.

Is this related to the crank position sensor?

It did not do this before even when it had the shutter.

Someone noted that the gap needs to be correct but we didn't see any adjustment on it.

Let us know.

Thanks,
Denise and Al

[Jon K]

Hey Folks!!!! GREAT news! The crank position sensor fixed it!!!!!!

My husband kept going back to the timing not advancing when you accelerated hard.

Wires were hardend and shrunken up at the ends of the connectors. Drives like a dream again.

Thank You and Take care until next repair.

Awesome bro - I'm here all week (much to peoples distain ehehehe)

The long cranking may just be coincidental. Is it consistent?

[632 Regal]

Reboot the computer to reset everything and your green again.

[Morgenster]

With all that fuel line work done it might be interesting to also change the FPR.

[russiankid]

It may happen that the CPS needs some adjustment. I know when my brother replaced one on his car, he had to use a washer to raise the CPS up a bit so it wouldn't hit the crank gear.

[genphreak]

I've an '90 M50 (525i) here with the exact same problem. The spare CPS out the back is gonna be used again.

Mine tends to get worse on hot days- in the cold it usually goes like a rocket.

She's been running on premium fuel as I've noticed that more octane tends to help. Incorrect timing sounds like an ideal root cause candiate.

WooHoo! I've been chasing air leaks, changed the coils and was about to do the O2, the FPR and the injectors.... there is noooo substitute for well-shared knowledge! Thanks again all. Can't believe I didn't even check the CPS gap before, doh!...

BTW; No long cranking on mine. She just runs like **** on hot days, then above 3000rpm its like the fuel line unblocks and kapoow! off ya go.

[caqueenslace]

How do you change the gap on the CPS on the tight side?
Does anyone know the measurement suggested for the gap.

We have feeler gages to measure but do not know what it should measure.

[caqueenslace]

One more question guys. The FPR is that the fuel pump relay or fuel pump regulato or fuel pressure regulator or fuel pressure relay.

My husband said could be any of the four but we are not sure if which one you meant.

We have an online catalog but the search found none of these so it is called something else. Go figure.

Any help would be great.

We just unhooked the battery and are going for a test drive now.

We will report back.

[Morgenster]

One more question guys. The FPR is that the fuel pump relay or fuel pump regulato or fuel pressure regulator or fuel pressure relay.

My husband said could be any of the four but we are not sure if which one you meant.

We have an online catalog but the search found none of these so it is called something else. Go figure.

Any help would be great.

We just unhooked the battery and are going for a test drive now.

We will report back.

I meant fuel pressure regulator. It's what keeps fuel pressure high when you accelerate.

[caqueenslace]

Great, that is going on next.

I'm still looking for the gap measurements for the CPS. Still cranking long. And it is varying.

[caqueenslace]

Hi Guys, We are still having the crank issue but it is intermittent. It is as tight as I can get it on the car. There is not gap at this point. Most times it cranks several times before it starts sometimes it starts right up. Never had this problem before we changed the crank position sensor. It's a bosch sensor. Could it be the wrong one? Bought it from FCP Groton online. Also can it be something else? Maybe new fuel pump? I would not think so because until we replaced the crank sensor it started up everytime with no problem. Let us know what you think. The car is running AWESOME otherwise. Once we restarted the computer a few times and put the muffler back on it is running perfect other than the over crank at start up. Thanks again.

[genphreak]

I've just done the CPS and it made no difference. Nticed however that the exhaust joints are leaking, adn last time I got rid of this issue they weren't. When the car's exhaust was replaced (all new resonator, muffler) it ran great. Now the bolts have loosened, so will go under and tighten em back up again and see if I can't make sure they stay tight with some Loctite or something. Would be surprised if this doesn't solve it... how's your exhaust?