Rough running engine and need help

[BigKriss]

I’ve been having some trouble with my car. It starts fine, but about 2/3 of the time it runs rough both at idle and while driving, like there is only 75% of power available or it’s running on 5 cylinders. I’m guessing it’s fuel/spark related fault. While driving it can be fine one moment and rough the next. The gas in the tank is good (refilled it with 98 RON petrol), the fuel filter was changed around 15,000kms ago, I checked all the spark plugs and they look fine.

I’m up to checking the resistance of the spark plugs leads and, I know this sounds easy, but how do you pull the leads off the distributor? I got the top one about 20% off (number 2 cylinder), but it doesn’t move easily and I don’t want to break the connector of the lead. I’m just wary about doing this because I haven’t mucked around with the ignition before.

[Bill R.]

Kris , just give the boot a 90 degree twist to free it up from the cap and then pull the boot straight off. Some are on pretty snugly but they come off . If you really have that much trouble getting them off then remove the fan and fan shroud first, then remove the dist. cap with the wires attached, then take your resistance readings from the terminals on the backside of the cap. Remember the plug wires are solid conductor so they have very little resistance in them, its the ends of the wires that have the resistance in them. 5K in the plug end and 1k in the Dist. end for a total of 6k ohms resistance on each wire.



I’ve been having some trouble with my car. It starts fine, but about 2/3 of the time it runs rough both at idle and while driving, like there is only 75% of power available or it’s running on 5 cylinders. I’m guessing it’s fuel/spark related fault. While driving it can be fine one moment and rough the next. The gas in the tank is good (refilled it with 98 RON petrol), the fuel filter was changed around 15,000kms ago, I checked all the spark plugs and they look fine.

I’m up to checking the resistance of the spark plugs leads and, I know this sounds easy, but how do you pull the leads off the distributor? I got the top one about 20% off (number 2 cylinder), but it doesn’t move easily and I don’t want to break the connector of the lead. I’m just wary about doing this because I haven’t mucked around with the ignition before.

[BillionPa]

i would place my finger at main system voltage. hook a volt meter with some long leads to the batt under the seat and keep it next to you, get a baseline, and see if it goes funky at the same time it starts running rough.

[BigKriss]

Thanks Bill for your comments. BillonPa, are you saying the battery could be ****ed? Because I replaced that yesterday.

[old bob]

As you know I have had some problems with my car's Transmission and was running rough like yours it has turned out to be a spark plug leads distributor cap and rotor now it is running well. Give that a try

[BillionPa]

make sure the new battery is at full charge.

i would suspect not enough current is getting to something in the motronic ignition system. or there could be corrosion on a ground or in the distributor.

when was the last time the pulse generator was replaced?

[BigKriss]

No idea when the pulse generator was replaced and no idea what one is.


make sure the new battery is at full charge.

i would suspect not enough current is getting to something in the motronic ignition system. or there could be corrosion on a ground or in the distributor.

when was the last time the pulse generator was replaced?

[BigKriss]

I didn't touch anything and the car is running fine now, it was running poorly for about 10-14 days, now it's fine again ??? The idle on initially starting the car though is really poor still. I'm getting a new 02 sensor, rotor and cap soon though.

[Podmore]

Let me know where you're getting your dizzy cap from - I was quoted $225 by Adelaide Motors BMW just for the cap, with another $1260 (!!!!) for leads (because they have to be custom made????). Anybody have a source for HT leads at a reasonable price?

[shogun]

Buy all that from www.autohausaz.com and it will be cheaper even if you have to pay for shipping USA to AUS.
Bulk ignition wires or tailor made sets you can buy at Kingsborne
http://www.kingsborne.com/wire.htm

[BillionPa]

note to self: avoid Adelaide Motors BMW like the plague.

[BigKriss]

My car is running fine now. I didn't touch anything. WHy would you deal with the stealer in the first place? What do you mean they have to be custom made? The rotor is usd$18.

The ignition system.
(http://realoem.com/bmw/showparts.do?model=HD22&mospid=47382&btnr=12_0049&hg=12&fg=05)
A Bosch ignition wire set for the 535i is usd$115. Aftermarket is usd$125.
http://bmaparts.com/item.wws?mfr=BOSCH&sku=BSH008979&price=113.40&orpartno=915431&cookieID=1Z80JIC8Y1Z80JPORL&image=http%3A%2F%2Fcatimages2%2Esophio%2Ecom%2Fweb app%2Fwcs%2Fstores%2Fservlet%2Fimc%2Fimages%2Ftn%2 F09506%2Ejpg

Distributor cap

http://bmaparts.com/item.wws?mfr=BOSCH&sku=BSH007470&price=48.50&orpartno=1695423&cookieID=1Z80JIC8Y1Z80JJR4R&image=http%3A%2F%2Fcatimages2%2Esophio%2Ecom%2Fweb app%2Fwcs%2Fstores%2Fservlet%2Fimc%2Fimages%2Ffull %2F03195%2Ejpg

I've read these are the best leads available, (http://www.moroso.com/articles/articledisplay3.asp?article=AboutSpiralCore.html) I wonder if they can be made for my car.


Let me know where you're getting your dizzy cap from - I was quoted $225 by Adelaide Motors BMW just for the cap, with another $1260 (!!!!) for leads (because they have to be custom made????). Anybody have a source for HT leads at a reasonable price?

[BigKriss]

I managed to remove the plugs today off the distributor cap. I twisted them a bit and used screwdriver on the rubber boot to remove the plugs. I then replaced the rotor and cap, the car still seems to run the same (normally).


Kris , just give the boot a 90 degree twist to free it up from the cap and then pull the boot straight off. Some are on pretty snugly but they come off . If you really have that much trouble getting them off then remove the fan and fan shroud first, then remove the dist. cap with the wires attached, then take your resistance readings from the terminals on the backside of the cap. Remember the plug wires are solid conductor so they have very little resistance in them, its the ends of the wires that have the resistance in them. 5K in the plug end and 1k in the Dist. end for a total of 6k ohms resistance on each wire.

[rob101]

Let me know where you're getting your dizzy cap from - I was quoted $225 by Adelaide Motors BMW just for the cap, with another $1260 (!!!!) for leads (because they have to be custom made????). Anybody have a source for HT leads at a reasonable price?
due to the fact that bmw doesn't give a **** about your business nor does anyone else in australia. I recommend you buy from BMA Parts or autohaus arizona as shogun et al have suggested.

[serg]

I’ve been having some trouble with my car. It starts fine, but about 2/3 of the time it runs rough both at idle and while driving, like there is only 75% of power available or it’s running on 5 cylinders. I’m guessing it’s fuel/spark related fault. While driving it can be fine one moment and rough the next. The gas in the tank is good (refilled it with 98 RON petrol), the fuel filter was changed around 15,000kms ago, I checked all the spark plugs and they look fine.

I’m up to checking the resistance of the spark plugs leads and, I know this sounds easy, but how do you pull the leads off the distributor? I got the top one about 20% off (number 2 cylinder), but it doesn’t move easily and I don’t want to break the connector of the lead. I’m just wary about doing this because I haven’t mucked around with the ignition before.
Cold temperature sensor?

[BigKriss]

I don't know. There are no problems with it anymore?


Cold temperature sensor?

[632 Regal]

you fixt it! Congrats!
I don't know. There are no problems with it anymore?

[mangler]

i went through same prob last month. fuel pump.

[BigKriss]

I didn't do anything to change it though. It fixed itself.


you fixt it! Congrats!