Poor running - any thoughts????

born

Member
 wirral, Merseyside
Hi
Just pressed my '03 3.0 E85 back into daily service after a 6 month period of inactivity. All seemed ok, but a bit rough running on start up initially. After a day of pootling about the rough running is way worse and I can hear a suspicious induction noise from the intake area.

The car also didn't pull cleanly through the rev range from cold and didn't want to rev past 4k. It got lots better when hot, but still not running perfectly. I decided to give it some love and have refreshed it with plugs & coil packs, intake rubbers and crank case breather valve and all 4 associated pipes.

I fitted all of this today and it went pretty well - bit fiddly but all good. I found a bloody big split in the rubber boot onto the throttle body and a few dodgy cracks in some of the breather pipes, so felt pretty sure I had found the issue.

I took it for a test drive and it appears to have made bugger all difference! Poor tick over from cold, stalling at slow speeds (very annoying in an smg equipped car), not revving easily beyond 4k and miss firing like a pig under load. Things improved once it was very warm, but still pretty bad at low rpm (again making manoeuvring a bag of laughs in an smg car).

Any one had experiences like this? There still seems to be a bit of induction noise, but I have always found the plastic manifolds make lots of noise. No change in rpm when squirting easy start around the intake pipe work and manifold and dont have a smoke tester (I wish!). Thinking maf, but not sure why things would improve as it gets warmer. Into temp sensors, cam sensors, lambda probes etc???!!!

Suggestions please?
 
Have you filled up with fresh petrol yet?
Disa valve??
https://www.youtube.com/watch?v=djmEK8h9IbY
 
The first thing I did was brim the tank with fresh fuel and I have fitted a new disa valve late last year.
Stumped!
 
Maybe just a case of rechecking every thing on the inlet manifold side of things? Perhaps something's not located correctly. Check the other forums also.
 
It's a sad world where an Italian tune up won't cure such things. Maybe I'm on the wrong forum, but have you checked the points (I'm going off for a lie down in a darkened room)
:D
 
Perhaps points and condenser will be the cure.....

In the good old days it really was those things and fixing stuff was much easier!!!

Contemplating junking the entire induction set up now jenvy are making throttle body manifolds for it! Perhaps a little rash though.
 
Hi born

My previous car had coil packs on the spark plugs. I had similar issues to yours. Ended up being the ignition amplifier module that sends the spark from the ecu to each coil pack.

I diagnosed the cylinder by disconnecting the coil pack cables one by one with the engine running, so the dodgy cylinder showed as not making any difference to the poor running, with all other cylinders there was a noticeable change in running. Being older and wiser - I wouldn't do this now as it leads to unburnt fuel reaching the catalyst which can damage it. A code reader saves the hassle / risk.

A new coil pack proved to be no use, so I did a continuity test across the ignition amplifier module which confirmed that the amplifier module was playing up on the diagnosed cylinder. The ignition amplifier was a simple plug and play change.

The caveat being this was not on a zed, but should be similar set up on a modern coil pack set up. Hope it helps fwiw. Good luck on the fix!
 
More info specific to BMW:
http://prodcds.bmwuniversity.com/library/bmw/Technician/Core%20Courses/ST055%20Engine%20Electronics/05_Ignition%20Management.pdf

The issue I had was with the equivalent of the ignition power transistor.
 
Thanks for the suggestion.
No codes present on my reader, so planning trip to indy (bm Wirral) for some advice and to scan some live data to see what's going on.
I wish cars loved me as much as i love them!
 
Management light came on this morning on my way to BM Wirral - Chris scanned the car and found a code for MAF issues, so new MAF on order and will be fitted tomorrow!

Lets see what happens then!!??
 
born said:
Management light came on this morning on my way to BM Wirral - Chris scanned the car and found a code for MAF issues, so new MAF on order and will be fitted tomorrow!

Lets see what happens then!!??
BM Wirral? I never knew this place existed. Any good?
Always handy to know of these sorts of places. I've tended to stick to Autotech Liverpool when I worked over there and last time my old E46 needed something I went to Trenics in Deeside.
 
Car in to BM Wirral for new MAF and all fixed and perfect. Chris (owner of BW Wirral) was superb and got me a great deal on an o.e. spec unit and fitted it in seconds. Codes cleared and off with a clean bill of health.

Can't recommend them enough - https://www.facebook.com/bmwspecialist
 
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