Running issue 325

Need technical Q/A then you're in the right place

Moderator: martauto

Kemlo
E30 Zone Regular
E30 Zone Regular
Posts: 342
Joined: Tue Sep 25, 2007 11:00 pm
Location: Birstall, West Yorkshire

Post Thu May 16, 2013 9:13 am

Morning all,

Car: 325i prefacelift (87 on an E), manual (was an auto), no engine modifications.

325 has developed a running issue this morning as I drove to work. At the lights it started to hunt for a few seconds before stalling completely. It fired up again, but immediately died again in the same manner. I fired it up again and it struggled a bit, but caught and then I just keep the revs at 1500 to nurse it to work.

It's okay under revs, pick up is fine, no noticeable hesitation under load. It does bog down a tiny bit when you come off the throttle, but I assumed this was normal.

There are no known airleaks, tested recently.

The CO reading was something like 0.7% at the MOT so based on feedback on here I assumed it was running lean. Until now it ran fine, but with a slightly high idle.

My wife reported that under light load cruising at 50 on the motorway it lost power, but it didn't stall (though she's not sure whether the revs dropped or not as she was too worried about being crashed into to notice).

I'll be taking it in to a garage to be looked at, but thought I'd see if you clever chaps had any idea's of some simple checks I could do myself before handing over any cash...

Thanks
Image
Kemlo
E30 Zone Regular
E30 Zone Regular
Posts: 342
Joined: Tue Sep 25, 2007 11:00 pm
Location: Birstall, West Yorkshire

Post Fri May 17, 2013 12:48 pm

Bump.
Image
Rtaylor2208
E30 Zone Addict
E30 Zone Addict
Posts: 3004
Joined: Mon Oct 11, 2010 11:00 pm
Location: Ayr, Ayrshire, Scotland

Post Fri May 17, 2013 12:57 pm

Failing CPS sensor possibly, as the wiring for it travels behind the pulleys and belts and is known to get worn through.
Speedtouch
Old Skooler
Old Skooler
Posts: 14124
Joined: Tue Feb 14, 2006 11:00 pm
Location: Canterbury

Post Fri May 17, 2013 1:53 pm

Sounds like it could be a sticking idle control valve - I'd remove it and use carb or brake cleaner to thoroughly clean it out.
///M aurice
ECU Upgrade EPROM Chips, £40 posted within the UK. Note these are not Zone chips.
viewtopic.php?f=6&t=279421
Rtaylor2208
E30 Zone Addict
E30 Zone Addict
Posts: 3004
Joined: Mon Oct 11, 2010 11:00 pm
Location: Ayr, Ayrshire, Scotland

Post Fri May 17, 2013 1:58 pm

Speedtouch wrote:Sounds like it could be a sticking idle control valve - I'd remove it and use carb or brake cleaner to thoroughly clean it out.
Would the ICV cause the problem described while the car was on the motorway?
Speedtouch
Old Skooler
Old Skooler
Posts: 14124
Joined: Tue Feb 14, 2006 11:00 pm
Location: Canterbury

Post Fri May 17, 2013 2:03 pm

Probably not, but it's worth regularly cleaning them out anyway, particularly if there have been issues with the idle.

I'd also be checking all the relevant earth connections, particularly the engine-to-body earth strap.
Last edited by Speedtouch on Fri May 17, 2013 3:12 pm, edited 1 time in total.
///M aurice
ECU Upgrade EPROM Chips, £40 posted within the UK. Note these are not Zone chips.
viewtopic.php?f=6&t=279421
Grrrmachine
E30 Zone Wiki / Team Member
E30 Zone Wiki / Team Member
Posts: 8043
Joined: Sat Feb 09, 2008 11:00 pm
Location: Warsaw, Poland

Post Fri May 17, 2013 2:36 pm

Could be a number things. Pull the sparks and see if they're sooty black, check the distributor to see if the arm or cap is warm, and pay close attention to what the rev counter does next time it cuts out or hiccups.