Stalling

just a quick question to the experts here, in the last couple of days the mighty bimmer has developed a problem. Today has been the first time it has let me down since I got it, after stopping to give way the car stuttered and died and would not start, I pushed it out of traffic and sat wondering how to get it home to fix the problem but after 10 min or so it started and seemed to run ok although I feathered the throttle and kept the take offs slow. It feels like no fuel getting through could this just be a case of a blocked fuel filter, I changed air and oil filters not long ago but didn't change the fuel filter(s) does any one know how many and where they are in a 1995 525i Australian build since this is where I will start to look for the problem? Even if this is not the cause it can't hurt to change filters at any time but could this be the cause of the problem, I run 98 ron fuel and the car goes well and this only seems to happen after breaking when I try to take off.

Change the fuel filters, your problem leads right there. You should have at least 1 if not 2 behind the right side rear wheel. When I changed mine (with no issues) they dumped what looked like mud out of them.

that is easy to check with the VIN in realoem. 525i should have 1 fuel filter
Fuel supply/single filter BMW 5' E34, 525i (M50)

Thanks for the info, since the stalling just happened today I haven't looked yet to find the filter but I will check behind the right rear wheel tomorrow. The car has been great untill this so I hope it is just the filter,I was not sure if it had one near the tank and another in line before the fuel rail for the injectors but filter was my first thought as the car seemed to run out of fuel and no other warnings came up in the dash and with seperate coil packs if spark was an issue I would expect to see warnings from the management system, can only hope it is that simple.

Rarely ever the fuel filter... I have never seen a clogged fuel filter.

If your crank position sensor is original... I'd check on the resistance... most of the time, it will check out ok.... So you need to check that while the engine is hot... the condition where your stalls.

It is most likely the crank position sensor... when it happens... pour water on the sensor and your car should start right back up... definitely the CPS.

Yes, I agree with the crank position sensor. I had a similar experience and it was difficult to determine if it was electrical or fuel related.
My sensor became intermittent and would fail sporadically, heat was not a factor.

Thanks I will check the CPS but I will start with the cheap and easy option as well, it can't hurt. I looked at the filter today and it looks like it has been there a long time so it should be changed, the car runs well along roads at speed and only stalls after breaking for corners ( I could try not slowing down) and then trying to take off but like you said I have not heard of a totally blocked filter although it could just be restricting fuel flow and is the cheapest starting point. Parts cost heaps where I am so I will order a CPS on line and try the filter while I am waiting.

200k is a lot of miles on an original filter. Back in the old days the fuel filters were much smaller and they would clog at much less miles. Then again it was a rarity that a car would make it to 100k

No local aftermarket filters so will get one from BMW dealer for $66 tomorrow, he says he has one in stock and he also agrees it is the place to start looking for the problem. This is still the cheapest place to start at this stage, there is a gauze filter on the bottom of the pickup in the tank but I won't go there unless I have to, could have picked up some crappy fuel as both the servo's near me are owned by supermarkets and they get the cheapest stuff they can. The only other thing that changed is I started parking the car with the nose facing downhill in a steep driveway because I still havn't solved the blocked sunroof drain at the back and it has been raining a bit, it was after doing this that the problem started (dosen't mean it is the cause of it) anyway I will start at the filter and work from there.

Have you checked under the power distribution box (under the back seat) for water ingress? This can cause annoying electrical troubles.

Quote:

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Originally Posted by genphreak

Have you checked under the power distribution box (under the back seat) for water ingress? This can cause annoying electrical troubles.

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+1 the leaky sunroof gave that one away!

Ok here is the latest info, changed the filter today and while fuel flowed out the input side it glugged out the other side and looked cloudy but after a drive to the shop all was well and the car pulled great all the way it died on the way home but unlike last time it cut out it tried time and again to start even manageing a rough idle for a couple of minutes before stopping again. I gave it quite a while to cool down in case it was heat related and again it tried to start over and over, firing after a few seconds only to run rough for a while failing to rev at all and then stopping. This went on for almost two hours and I finally called a tow truck who said they would be about 20 min or so, while I waited I tried again and after rumbling away suddenly almost with a click it settled and ran without a hitch so I risked it and drove off and although it burped a couple of times I got home safe. The strange thing is I went out 20 min later and tried, it started and ran with no hint there was anything wrong at all, I will check under the seat tomorrow but it is looking more like a sensor gremlin . I looked where I thought the crank sensor was but could see nothing I thought it was on the exhaust side I think behind where the aircon pump is can someone tell mhere to find it and the connector so I can check if this is the problem (stage two)

It's located behind the thermostat housing.
The plug end is difficult to get to.



https://encrypted-tbn3.google.com/im...Yo6dpkW-vV66pQ

Definitely CPS... no doubt. Get a bright flashlight and you can see it.

I don't know, but does this sound like the MAF symptoms? Seems like I've seen a few guys that had this kind of intermittent problem that turned out to be the MAF.

How much has to be removed to change it out and where do I find the part number on real oem? I have looked but don't know which section it is under.

Ok I will try the CPS I just have to find where the plug is I can see the sensor but the wire goes down under the intake manifold and from one diagram plugs in down there (I think) do I have to pull much off to find it, I called a guy in Sydney and he said the part number is 12141730027 but Pelican and Real give me 12141726066 so I think the best action is to remove the old one and get the part number off there first to be safe. Have been quoted $223 from BMW here but will have to wait two weeks as they are on backorder, the guy in Sydney was $195 for aftermarket part and has in stock (at least the part he said it was) or order from US for around $80-$90 including post + waiting time. Once I know the part number I will get from US I think seeing I have to wait to get from dealer anyway.
Three mechanics I have spoken to said they would put money on CPS as problem but if someone can tell me how to test I will try that first to avoid throwing money at ghosts.

Ok I think my car has both crank and cam sensors, should I order both from US plus intake seals and just do the lot in one go to be sure what is what, at least I would know all is right there and check for vacume leaks at the same time. Please any info on how to check would be good and how best to get to the plugs so I know what to order.

Sorry to keep posting the same question but I have the new crank sensor on the way and just want to ask again where the connector sits under the intake, if I know where I am reaching for I can work on taking out only what I need to to reach it. If I cant reach it with my hands the wife might get to do something new, she has small hands but does someone have a picture of it while they were working on the manifold?

Ok I got the CPS out, not too hard just took my time and didn't force anything. I checked the resistance and it was 504 but the car starts and runs well until it has been at operating temperature for a while and then fails so I carefully heated the sensor and checked again, it was 580 and climbing, still not as hot as it would be stuck to the front of the motor, should it change that much as it heats up or should it stay the same? The testing instructions do not say to test only when cold so does that mean it makes no difference and my readings say the sensor is failing with heat. Further to this I tried heating again, the first time it was warm to touch but this time I went a bit further, more to where the engine would get it to, I held it not in but a good 6 inches above a flame until it was too hot to hold but well below where it would melt the plastic part above the sensor the reading was 650 well out of range. I watched the meter drop one point at a time as it began to cool but only time will tell if this was the problem now I wait for the new part.

A good drive will tell you if you solved the problem or not.. CPS is a tricky thing to test regardless of how the manual tells you so. In BMW, it is very very very common to go bad. in older MB of same era or older... not common at all. The new MB has CPS problem at higher mileage... typical symptom will be engine dying when engine is hot... pretty consistent to temperature. In winter... not so much.

Other thing with CPS is that you might notice the engine is running hotter with faulty but functioning CPS. After change, the engine runs cooler. This is observed on my friend's MB.

and check the fusible link(s) for haircracks
BMW E34 Website

fuseable link location pic


my E32 750 has 2 fusible links, not sure how many your model has.

So Ferrett 1962... what is the verdict?

Still waiting for the part, $200 to buy here and even the dealer said it was on back order got it from UK for $37 incl post just waiting for it to get here.

OK so the new part arrived and installed car started fast and seemed to pull better but now cutting out, idle fine then almost stop then jump back to normal. I replaced the CPS and the car started fine, drove around the block and all seemed well untill the car cut out and ran fine again so I headed to the driveway and let it idle and it stopped again, waited five minutes and it started at 700rpm ran for a while and slowly dropped to about 500 to 600 rpm almost stalled and reset to 700 rpm for a while. so I held the throttle about 2000 rpm and the car seemed to do ok but again almost stalled and jumped to 2000 rpm. This is ongoing, the car seems to run well but will not rev above 3000rpm and continues to almost stall and then rev until cutting out, I removed the maf connection and the car revs dropped for a second then acted like before with reving then cutting out them reving again. Strange situation even with a lot of heat the car seemed to run but not right, I have not reset the system by removing the battery for a while so could that help or any other ideas?

Mmm... sounds familiar... let's see if others knows the answer.

Sounds like a plugged cat converter to me... but I may be wrong. It may also be a bad CPS... what brand is it? What is the resistance?

I'd reset the computer just to have it recalibrate the engine.

Just remembered something similar to this... it was the position of the crankshaft position sensor... make sure it is absolutely tight!

And check the clearance between the sensor and the cogs.

Not much adjusting to do, they pretty much bolt in and thats it. I'm old school and still betting on fuel delivery issues, gunk in the tank or something if the filter seemed to be clogged and that helped.

Another thing that would seem similar is a weak ignition, same symptoms as lack of fuel. Plugs/wires/cap/rotor all good? Check that aspect so you can wipe the board of the issue. This is as stupid as my 850 not starting after driving it into the garage.

So after last night tried to start today and started ran for a bit and stopped and would not go, I pulled the negative off the battery for 30 min or so and it started again for a short time and stopped now just no go at all, checked new sensor and and got 703 so it seems it might be a dud, refitted old sonsor but still no start will crank over just not start it seems whatever was failing has gone I am starting to think it might be the fuel pump so I will start checks on that starting with the relay. I will not be beaten by this I will find and fix the problem, no more parts, I did not mind the couple of things I changed but no more without a lot of tests. I can't get to a place that can read codes so I will do it the old way check and check, mine is a 95 with seperate coil packs and I don't see all them going at once so if it is spark it must be the triger that makes them work is the problem but for now research forum for fuel pump and go from there.

The word is anything but the expensive sensors (CPS) at the dealer are junk. you can buy 4 and 3 will not work, so do think of that angle. Just cause you got new dont mean they work is what I have read.

Run a small wire from the pump up to your volt meter where you can see it to count that out. Stupid **** always catches me off guard.

Get fuel pressure gauge to test the fuel pump... easy test from engine compartment. You do need that T adapter and extra hose and clamps to do the connection.

I know there is no adjustment on the CPS... but I do recall one time on this forum... someone installed it and it was hitting the cogs... thus destroying the CPS... don't know how that happens.

The general consensus on the CPS is that if it looks like the orignal... all metal housing, then it is probably ok... but if it is plastic housing and a round sensor tip... this is junk.

Since you usually get what you pay for. After spending over $200 the sensor should be good.
This problem really did sound like it would have been the CPS.
Just wondering if there are any error codes that come up.

No error code because he disconnect the batteries.

Well after some testing I believe the fuel pump is the problem, tried to start this morning and no go so did bypass for fuel pump and the pump kicked for a second and stopped tried to start and the car started for a second and cut out also no more sound from the pump. I did check for power at the fuse with and without the bypass and had power through fuse so I checked at the plug for the pump as per service book again with and without bypass and had power to terminal 5 with the bypass but not without so it looks like the pump. Any other tests I can do before I try to find a pump I don't have to sell a kidney to pay for? Just looked on ebay, does anyone know what TREperformance pumps are like. Called the dealer and they will have to order from Germany and they want $555.67 for one but I will pull mine out first to make sure I get the right part OEM lists it but I want to make sure, dealer says two weeks but I can get it from USA quicker can someone advise me of a good brand to go for.

Can't you order from USA? Like Rockauto.com or bmaparts.com?

In USA... there are cheap chinese fuel pumps for like $35.

That $555 is the complete assembly with fuel level sensor... you can just replace the fuel pump alone and reuse the rest of the assembly.

I know I can just replace the motor from the pump but I will pull it out first to check part number before ordering and to check the frame it sits in is not damaged, I was just wondering about the cheap pumps and if they are reliable or total crap. Any ideas on a brand with a good record from people in the states, there are a number on ebay claiming to be good ( as you would expect) but are there any I should avoid?

Ok so I pulled the fuel pump (not as much fun as it sounds). This morning I tried to start again with no go so I again ran the bypass for the pump and the car started, ran and stopped three times then nothing, so after removing the pump I connected power to it and it worked but sounded strained and pumped the last of the fuel in it in spurts, when empty it ran smooth and quiet only for a few seconds because I know it should not run for long dry. After this I connected the wires from the sender to it again plugged in the harness and reconnected the battery, ran the bypass for the relay and the pump ran non stop again only for a short time (don't want to stuff it if it is ok). Could it be that it works but can't build preasure? is it ok to sit the bottom into a water bucket and see how well it goes or will that cause problems, I am not sure how they work and don't want to waste money on something that is not broken.

For your safety... I'd say stop playing with the fuel pump... don't want flash fire or explosion from sparking. If you goes back a couple of years ago... china fuel pumps are crap... even though some of them do offer lifetime warranty... which means nothing because it cost you money to send it in to them and a car that is not running.

Most of the problem with the China fuel pump is the failure of checkvalves... and also the fuel pump pressure. Nowdays, if you buy a brand name one... it should be okay...

Again with BMW's, it is also very common for the fuel pump to go bad too... fuel pump and CPS are the two things that goes bad all the time as the car get older. Since you said the car ran better with new CPS, it is no doubt that the old CPS is not good. Now you just need to get the fuel pump and move on.

I was very carefull with testing the pump and don't need to do more with it, got new pump here in OZ and it is already on it's way express. Mine was a pierburg pump and the new one is a direct replacement with no mods needed, should be overnight delivery so I hope it will be here tomorrow morning then I need a couple of clamps and it should be good to go crazy At least with getting from Australia I don't have to wait for it to get from USA or other.

TrePerformance are excellent, but have an external inline check valve handy when you do the install. Out of two I've installed, I needed the check on one. The TrePerformance pumps are fine, but the install is fiddly as you have to solder the wires and set the in-tank pump height after fitting it in the pump cage.

An OE one wit the full cage is a simple install as all that comes with it, not just the pump.