316i running issue, help?

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

Moderator: martauto

bigwinn
E30 Zone Squatter
E30 Zone Squatter
Posts: 1832
Joined: Wed May 05, 2010 11:00 pm
Location: Lincolnshire/Leicestershire border

Post Sat Feb 04, 2012 3:41 pm

Afternoon

Managed to get the car home, but developed a running fault.

Best way to describe it is a slight hesitation on acceleration, nothing on deceleration, but quite a misfire on idle at speed, eg when coasting at 60.

It's just juddering, it's not a bang or otherwise.

Fault came out of nowhere, no signs of it coming. Idles ok at standstill.

It's a 90 316i auto

Where to look first?

Stu
Bronzit gone- she lives on
'89 325i auto touring: Malachite Green

Now, I'm no gynecologist, but I know a tw4t when I see one...
Rtaylor2208
E30 Zone Addict
E30 Zone Addict
Posts: 3004
Joined: Mon Oct 11, 2010 11:00 pm
Location: Ayr, Ayrshire, Scotland

Post Sat Feb 04, 2012 3:52 pm

Id check the leads first to make sure they all look in good condition. Try wiggling them when idle and see if the problem comes back. Nice and easy one to start off with.
bigwinn
E30 Zone Squatter
E30 Zone Squatter
Posts: 1832
Joined: Wed May 05, 2010 11:00 pm
Location: Lincolnshire/Leicestershire border

Post Sat Feb 04, 2012 3:55 pm

Will do, although were new not that long ago....

Stu
Bronzit gone- she lives on
'89 325i auto touring: Malachite Green

Now, I'm no gynecologist, but I know a tw4t when I see one...
Rtaylor2208
E30 Zone Addict
E30 Zone Addict
Posts: 3004
Joined: Mon Oct 11, 2010 11:00 pm
Location: Ayr, Ayrshire, Scotland

Post Sat Feb 04, 2012 5:13 pm

It could be a mixture issue as well, but thats more difficult to test for, post back on how you get on.
bigwinn
E30 Zone Squatter
E30 Zone Squatter
Posts: 1832
Joined: Wed May 05, 2010 11:00 pm
Location: Lincolnshire/Leicestershire border

Post Sun Feb 05, 2012 6:25 am

Ht leads and associated cap/dizzy look ok

Where next to look.

I'm confused as it came on so quickly and out of nowhere...?

On past motors, stuff like this is due to a hairline crack on the dizzy cap or similar....

Thoughts?
Bronzit gone- she lives on
'89 325i auto touring: Malachite Green

Now, I'm no gynecologist, but I know a tw4t when I see one...
User avatar
Brianmoooore
E30 Zone Team Member
E30 Zone Team Member
Posts: 49360
Joined: Mon Jan 10, 2005 11:00 pm

Post Sun Feb 05, 2012 10:10 am

Check out the big air pipe between the air meter and the engine.
bigwinn
E30 Zone Squatter
E30 Zone Squatter
Posts: 1832
Joined: Wed May 05, 2010 11:00 pm
Location: Lincolnshire/Leicestershire border

Post Sun Feb 05, 2012 6:35 pm

Can't see any obvious cracks

Would that indicate the issues described?
Bronzit gone- she lives on
'89 325i auto touring: Malachite Green

Now, I'm no gynecologist, but I know a tw4t when I see one...
bigwinn
E30 Zone Squatter
E30 Zone Squatter
Posts: 1832
Joined: Wed May 05, 2010 11:00 pm
Location: Lincolnshire/Leicestershire border

Post Mon Feb 06, 2012 1:27 pm

Tightened all pipes/air hoses etc

issue is intermittent, eg it runs fine then lumpy and stalling

emissions smell 'different' too

fuel pump fine, sparks look fine

could this be anything to do with crank position sensor?

Stu
Bronzit gone- she lives on
'89 325i auto touring: Malachite Green

Now, I'm no gynecologist, but I know a tw4t when I see one...
bigwinn
E30 Zone Squatter
E30 Zone Squatter
Posts: 1832
Joined: Wed May 05, 2010 11:00 pm
Location: Lincolnshire/Leicestershire border

Post Sat Feb 11, 2012 4:44 pm

Fixed...

Was air leak

Thanks all
Bronzit gone- she lives on
'89 325i auto touring: Malachite Green

Now, I'm no gynecologist, but I know a tw4t when I see one...
User avatar
Brianmoooore
E30 Zone Team Member
E30 Zone Team Member
Posts: 49360
Joined: Mon Jan 10, 2005 11:00 pm

Post Sat Feb 11, 2012 7:55 pm

bigwinn wrote:Fixed...

Was air leak

Thanks all
Whereabouts?
bigwinn
E30 Zone Squatter
E30 Zone Squatter
Posts: 1832
Joined: Wed May 05, 2010 11:00 pm
Location: Lincolnshire/Leicestershire border

Post Sat Feb 11, 2012 8:07 pm

tightened all jubliee clips, the worst was a breather from the back of the inlet boot,

prior to doing this it happened, after all tightened no issues, just did 20 miles on it and not a missed beat

I am going to change the CPS- are they different between models?

Stu
Bronzit gone- she lives on
'89 325i auto touring: Malachite Green

Now, I'm no gynecologist, but I know a tw4t when I see one...