M50 Idle Problem

[E30BeemerLad]

For some frustrating reason, the M50 mill in my touring has developed a strange idle problem.

It had only ran briefly before after I had put the head back on last year, as per the video below with no exhaust manifold

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Now, after doing nothing with it for many months (other than jacking the engine on the driver side when wrestling to fit the S50 manifold, it now hunts up & down the revs.

I've taken a wee video clip of that to assist incase the symptoms seem specific of a certain problem.

Had the ICV off and given it a squirt of car cleaner and then some WD40, doesn't really seem to have made a difference. My brother reckons it could be the air meter as when he disconnects it, the idle drops low down but it stops flaring up and down the revs. Before I start buying loads of unnecessary replacement parts, has anyone some words of wisdom?

[youtube][/youtube]

[baptie0]

hi mate

my car has done exactly the same thing in the past,

it stopped doing it by itself so i dont know what causes it.

all i did was check for any air leaks, which it did not have.

sorry, not much help really.

[daimlerman]

I have a s/h MAF that I bought when I was having 'running rich' issues.Let me know if it's any use to you..

[E30BeemerLad]

hi mate

my car has done exactly the same thing in the past,

it stopped doing it by itself so i dont know what causes it.

all i did was check for any air leaks, which it did not have.

sorry, not much help really.

Lot of similarities going on here Jonny

Malcolm, I'll let you know about the air meter, got one lined up already.

[Omi]

Bob has an M50 ICV spare too, if I recall correctly.

[dicko]

My m50 does the same after the battery is disconnected but it clears after 30/40 mins of driving

[secondtimelucky]

What was it you were about to say at the end of your vid eh????

[E30BeemerLad]

What was it you were about to say at the end of your vid eh????

"piece of schit"

[dicko]

How long have you left it running for .

[E30BeemerLad]

not long as I haven't put coolant in it yet, doing that tonight when I get some antifreeze

[punk_sy]

my 520 does this a couple times a month dont know what it is but its fine for another two weeks lol

[daimlerman]

Thinking about this,could it just possibly be a confused blue temp sender?
Try it again when you have coolant in....
You have swapped the brown(temp gauge)sender for a single pole E30 type?

[dicko]

Like i said mine does this for 30/40 mins after battery is removed and gets slowy better as you drive , I had tps problem and fitted a new one but the car still does this with new tps fitted . fill it with coolant drive it for an hour and see how it is then .

[E30BeemerLad]

Thinking about this,could it just possibly be a confused blue temp sender?
Try it again when you have coolant in....
You have swapped the brown(temp gauge)sender for a single pole E30 type?

Not touched the senders malcolm, not sure if the previous chump that had it running on chocolate milk had touched them, probably not as I'm sure it got fitted and promptly did a large amount of diffin around a field before being sold to yours truly.

Never got the coolant or anything done tonight as worked late and had some crap to do around the house, either tomorrow night or weds for defo.

[daimlerman]

Then check your brown sensor before adding coolant just in case!
Pull the wiring plug off,you are looking for one terminal blade,if you find two,you are off to the stealer for an E30 temp gauge sender,and tell them it must be a single pole one!
I found that a deep socket would just fit over the senders to remove/fit them,but take care,if the socket twists sideways it will take the top of the sender...

[E30BeemerLad]

I checked the sender this morning, a 2 pin variety.

Am I going mad or is the brown sensor for the gauge? If so surely this would have no bearing on how the car runs/ ticks over?

If it is not the gauge sensor and is for the ECU then surely the ECU will want to recognise the original sender that was in the E34 originally as engine & ECU are from the same original vehicle?

Have I lost the plot?

[daimlerman]

Yes,brown sender is for the gauge,just suggesting you swap it before filling the system to avoid the probability of air entering later....
Running the engine with no coolant may confuse the signal that the blue sender is signaling to the ECU,so getting coolant in would be good.
Having the correct temp gauge sender(single pole to suit E30 cluster)means that you can monitor cylinder head temp yourself,also good news.

[DanThe]

Generally, when the blue sender fails you will find the engine wont run once warm

[E30BeemerLad]

Well she now idles smoothly, thanks to Bob_S for the ICV, Legend!

Picking up a new brown temp sensor on Saturday morning from my local stealers.