Over revving and other issues

[igb]

I'm sure you will get there Tris, good you have some help on Saturday and I agree with the logical approach.

Only thing I would add is to check that one of the injectors hasn't come out of the intake manifold. This happened to me when I was having mixture problems. One of the injectors had a broken clip and engine must have back fired into the intake manifold.

It would account for the smell of petrol and it certainly won't start in this condition.

Ian

[Nick H]

Tris,
      I have the base setting procedure for the fuel metering head out in the garage.
I’ll post it on here tomorrow. That will get you in the ballpark for the fuel mixture.

Nick H

[Nick H]

   
Tris,
       Here’s the base setting procedure. You will need to disconnect one of 
the fuel lines to a injector on the top of the metering head so you can see the 
fuel level in the port.

You will need to jumper the RPM relay socket between the connector where pins 30 and 87
on the relay would plug in. So the fuel pump runs continuously while your doing
the setup. 

I received the procedure with my new metering head from
DeLorean Go but I think it originated from KMI injection who are the
experts in K jetronic.

Hope it helps

Nick H

[TristanC]

Thank you Nick.

I appreciate that. I’ll get it printed off in readiness. 

Cheers
Tris

[TristanC]

Just a quick update - I had a chance to try one more time this evening and she fired up!

Ok, so she needed full throttle, and a number of cranks, but she fired.
Didn’t stay running and wanted to cut out.
She ran extremely rough and is possibly missing.

I assume wet plugs from over fuelling the other day......

Anyway - I’m a step forward. At least I can assume the ECU’s are ok.

[TristanC]

Ok everyone, normal service has resumed!

I got to the car before Stu came and she started right up, but very very rough and lumpy.
But she stayed running.
She smelt very rich, so I leaned the mixture and she was getting better and better until she was running smooth.
Ok, the high idle also came back, but at least I was back where I started.

By this time Stu arrived and we tried a few things, including a replacement RPM relay.
Then we tried a spare idle motor Stu had and hey presto!! Back to normal idle.
Literally we were trying things for 15 mins or so and bam!!
Idle motor!! Whoop!

So Stu has kindly let me borrow this one, while I try to clean my original up.

Happy days!!!!

Thanks everyone for the input and support.

I’ve got a few jobs to do before getting back on the road.
(Oil and filter after the fuel flooding, angle drive and I’ve just removed the seats for a local chap to restore.)

Tris

[Nick H]

Nice one guys!   
Glad you got it sorted.

Nick H

[TristanC]

Just another update

It’s idling high again..... so weird.

I cleaned the old idle motor, and a piece of small metal fell out. It still worked when energised with 12v
So just to rule it out 100% I reconnected it.
She wouldn’t even start.
So I put Stuart’s temporary one back on and she idles high back to 1,500 rpm this time....

I’ve rechecked all the vacuum lines, they are all ok. I’ve even just received a brand new idle motor from Germany (£45 from eBay) and that reacts the same as the original idle motor before the cleaning and the same as Stuart’s temporary motor. I.e. high idle.

So it seems I’m back to square one.

Is there something that switches the car to high idle when AC is on? This seems to be the only link to me.
Before we got the car idling by replacing the idle motor, we tried Stuart’s RPM relay, to no avail. But could the swap of RPM relay have reset something? Albeit temporary?

Also, perhaps my idle motor with a missing bit of internal has blown a fuse???? If so do we know what fuse?

Sorry all...... and thank you

Tris

[Chris Williams]

Quote:Is there something that switches the car to high idle when AC is on?

No,  One thing that occurred to me is I wonder if the plunger/piston in the metering head is not moving in it's chamber. I'm struggling to think of other options now.
Chris

[Nick H]

Chris could be on to something here. With the air cleaner removed have a look at the position of the big round disc aka air metering flap.

If the flap has no resistance when you press it down after just switching off the engine then that plunger/piston could be stuck. In your case the plunger would be sticking just at the bottom of its travel. This might make it very difficult to diagnose as the amount of free movement between the leaver and plunger could actually be very small.

But basicly the plunger won’t be pushing down on the leaver attached to the metering flap allowing more fuel and air into the engine than you should have.

Maybe if you give the fuel metering head a light tap with a plastic/rubber mallet when the engine idle is high and see if the idle speed changes?

Be careful if you end up removing the fuel metering head as the plunger can drop out.

Nick H

[TristanC]

The flap does have resistance after turning off - I guess the accumulator is therefore doing its job here too?

But I will definately recheck this at the weekend.

Cheers
Tris

[Rissy]

Another suggestion. Look at the integrity of the throttle arm - linked to the throttle spool. Is there ANY slack in that? There's a small 8mm balljoint on the lower half of the arm where the link arm clicks on to. Is it still tight with no wobble? This was one of my areas of issue. This, along with another few things was meaning the car wasn't returning to the fully rested position at idle. When the throttle spool is at idle position, when it clicks the idle speed microswitch (presuming it IS doing this!?), if you push with your finger at the top of the arm towards the fuel distributor, can you get any movement in this arm at all, possibly then resulting in a drop of revs (or not) even though the idlespeed microswitch might be clicked?

How does the engine perform at idle with the CSI disconnected (disconnecting it BEFORE you start the engine!)?

Be VERY careful if you remove your fuel distributor to allow that plunger to fall out. It must be stressed that if that thing drops and hits anything hard, it's game over for it, and you'll need to buy a replacement. It's a precision piece of engineering with very very small tolerances, so if it gets damaged in the slightest, it wont work any more. Just a warning.

[Nick H]

(29 Aug 2018, 13:03)TristanC Wrote: The flap does have resistance after turning off - I guess the accumulator is therefore doing its job here too?

But I will definately recheck this at the weekend.

Cheers
Tris

Like I said it will likely be sticking at the bottom of it’s range of
movement. In other words it’s not quiet returning to its rest position.
This will be tricky to feel by pushing the flap as I bet we are talking a very small
amount of free play before the leaver hits the plunger.

If you look at K Jet trouble shooting, once you have eliminated the
Idle motor and vacuum/air leaks. Your pretty much left with checking free movement 
of the metering head plunger. 

Nick H

[TristanC]

Hi guys,

Sorry I missed the replies yesterday. Thanks for those.

I’ll have a crack at all the suggestions as soon as I’m back with her. (Stored in my parents until I get her sorted)
Seats are out for a restoration too....

Cheers - and I’ll report back once I have more news

Tris

[TristanC]

Ok.....

Throttle arm didn’t have any wobble. And no extra movement as you mention Rissy.
The Cold start injector didn’t make a difference when disconnected.

Stu came over again to help me (thank you Stu) and he tapped the fuel distributor a few times, but no effect on the idle.

I now have a brand new idle motor and that made zero difference.

Then we tried Stuart’s idle ecu...... and the revs dropped!
So it looks like the idle ecu is the issue. Stu also dialled in the mixture for me. So that’s spot on now too.
It still idles around 1,000 rpm. But it looks like that’s the best we can get at the moment.

But now it looks like I need a rather expensive idle ecu..... unless Rich H is able to rebuild......

Anyway. Good news that it seems we have identified the cause. Strange that the idle motor fixed the revs..... then it didn’t...... and now the idle ecu fixed it......
It baffles me.

Sooooo, idle ecu, here I come!

Thanks everyone.

Tris