535I engine missing after tune up

[1990535IM]

1990 535I 150K miles - was running good no miss - slight off idle hesitation.

Tune performed includes:

Spark plugs - Bosch Platinium 2
New BMW distributor Cap and rotor
New rubber from air cleaner all the back to intake 2 large tubes replaced and small tube to Valve cover.(vaccum line reconnected)
Adjusted Valves found 3 exhaust valves to be tight adjusted to .012

Problem 1:
Broke a inductive pickup off one of the distributor wires (3rd plug wire on distributor cap not sure what spark plug or if it goes to the ignition coil) - I have since glued this back together not sure what it is for?? Did not change the problem. - plus this could be the problem.

Point of this post:

Car runs much better except for a miss under hard aceleration mostly between 3 to 4 k RPM. This is intermittant and if I acelerate slowly does not occur.

So any sugestions on:

1 - Inductive pickup wire I broke - what it does??

2 - Problem with my car

3 -Bosch Platinuim 2 spark plugs??

I have been trolling this site for a while so look forward to interacting with this group.

Thanks in advance!!!:D

[Martin in Bellevue]

The inductive pickup goes over the spark plug wire to cylinder #6. This "sensor" directs the dme to split injector duty between 2 banks of 3 each. The 1.3 motronic on the 535's allows for 3 injectors to fire at a time, instead of earlier versions firing all 6 injectors together. This prolly won't cause a noticeable problem in driving.
Get the correct Bosch silber spark plugs for the m30. M30's don't like platinum plugs. This is likely yer problem.

[Scott H]

always stick with specified plugs on the M30


The inductive pickup goes over the spark plug wire to cylinder #6. This "sensor" directs the dme to split injector duty between 2 banks of 3 each. The 1.3 motronic on the 535's allows for 3 injectors to fire at a time, instead of earlier versions firing all 6 injectors together. This prolly won't cause a noticeable problem in driving.
Get the correct Bosch silber spark plugs for the m30. M30's don't like platinum plugs. This is likely yer problem.

[Martin in Bellevue]

always stick with specified plugs on the M30

Oh great, another DITTO post.
Damn good help there, scotty.

[Scott H]

"You have been banned for the following reason:
needs a valium - and to leave work

Date the ban will be lifted: 12-01-2005"

Just b/c we're not all playing with fuel management and ignition stuff doesn't me we don't have something to offer.



Oh great, another DITTO post.
Damn good help there, scotty.

[Martin in Bellevue]

"You have been banned for the following reason:
needs a valium - and to leave work

Date the ban will be lifted: 12-01-2005"

Just b/c we're not all playing with fuel management and ignition stuff doesn't me we don't have something to offer.
You did seem to run out of midol today.:)

[Kalevera]

Bosch W8LCR


best, whit

[Alexlind123]

Its always nice to hear more than one opinion, even if they are the same. The PO installed platinum plugs in my car, and now with two people saying that the m30 doesnt like them, i will buy regular bocsh plugs.

[1990535IM]

Yes this will be my first step -- Thanks all



Bosch W8LCR


best, whit

[1990535IM]

Thanks - for info on inductive pickup - plus - replace your plugs again - Will do ASAP

[athflying79]

I used Bosch Platinum's with the 4 prongs...don't remember what they are called. Anyway, my car was idling like crap and hesitated when cold. I did the plugs, rotor, and cap....it runs much better now. Since I did it all at once, I can't contribute it to one thing or the other, but I haven't had any problem with the plugs. Next time around, I will go with regular plugs simply for the price difference.

[Robert K]

If I remember correctly, Bruno's site says the the 3.5 liter motor also likes the plug gaps opened up to .034 - .036. It has been found that the slightly wider gap promotes a better idle. If you decide to adjust the valves, I believe a slight change to a wider clearance has also been found to help idle. If memory serves me well, the stock clearance is .012 cold. The advice is to set them at .013. Hope someone can back me up on this because it wasn't listed on Bruno's site.

Grace and peace,

Robert K
1991 535i

[GS535i]

Do Bosch actually supply a silver electrode version of the W8LCR ( ie W8LSR, if they follow the same nomenclature)? I have used the 'silber' with superior results in both 16v and 32v 928s ( the 16v ones have 12 years on them! - and are still perfect).
I do have the Bosch +4s in the 535i, and they are fine - the M30 never hesitates idle to redline..... but a single silver electrode would be the first choice.

[1990535IM]

OK - I replaced the Bosch Platinium 2's with

W8LPR part # 6234 - not the W8LCR as posted - any spark plug experts out there know the difference??

Gapped at .030

I got my car back - No more miss!!! Plus the off idle hestiation is gone - rotor and cap were in bad shape.

Live and learn!!!!

Thanks all for the responses.

PS - Martin and Scott quit your bickering - !!!

[Kalevera]

Idle might be a little rough at .030; I run them around.

LPRs are platinum, versus the copper LCRs.

best, whit

[genphreak]

Its always nice to hear more than one opinion, even if they are the same. The PO installed platinum plugs in my car, and now with two people saying that the m30 doesnt like them, I will buy regular bocsh plugs.Platiunums are supposed to last for ages... (according to Bosch) , I had to get mine, its all the shop had. My M30 has done 5k with them and runs fine (but I believe my consumption is high)... I only get 16mpg (15l/100km) around town, 23.5mpg (10l/100km) [that's US gallons, not English btw] on the highway. (cries) C'est la vie!

[Paul in NZ]

I only get 16mpg (15l/100km) around town, 23.5mpg (10l/100km) [that's US gallons, not English btw] on the highway. (cries) C'est la vie!

sounds about right to me