Over revving and other issues

[TristanC]

Sorry Nick - no, I’m confusing myself now!! Sorry

To clarify, with the bung in the revs INCREASE.
Bung out, revs DECREASE.
I.e the opposite that we all would expect.

In fact, with the bung out it almost idles as normal....

Even with the Allen key in place to adjust mixture, it’s almost as if the bung is there and revs increase. (In my unique scenario)

[Nick H]

I am grasping at straws here.

Somewhere there is ether more fuel or more
Air getting into the engine.

CO set to rich?

Have you checked the cold start injector? Could it be faulty
and injecting fuel all the time?

It’s definitely a interesting problem your having.

Nick H

[TristanC]

I thought about the CSV - so disconnected that and restarted with same issue.....

Possibly too rich.... I think that’s what the advice I had was regarding disconnecting the o2 sensor and turning the mixture to reduce idle - due to my previous tampering with the mixture....

I’ll get there!!!
(Took her for a short run yesterday regardless of this and she was great.... and lifted my spirits a little)

[TristanC]

Ok back with the car today.....

Still not quite right and still revving high around 1500

However, having adjusted mixture (again, I know, I know) it started to run a little better. And the covering of the idle screw opening no longer increases revs, but does actually reduce it.
So I’m getting there.

I also have a dwell meter now to help. But while trying to get the dwell between 35 and 45, she doesn’t really like it.... and the mixture has to be adjusted so the dwell is more 55-65.
So there may be something else at play for me, but all the same, she’s running quite well otherwise.
So much so, Mrs Carroll and I took the D out to the beach for a coffee.

The saga continues..... but I’m getting there.

[TristanC]

I’m getting there. She’s pretty much idling nicely as of last night.
This was when she was warm.

I tried this morning and she’s still running and idling, but give a little “gas” and she coughs and splutters a bit. After a few minutes though, that clears up and she accelerates freely.....
Still a mixture issue perhaps?

She always ran perfectly from cold before all this drama - so I can now only put it down to mixture....

[Chris P]

You have changed and disturbed lots of stuff Triss.......any one..or even  two might caused an extra slight issue....2 faults then.

Sorry to sound negative, but  it might not be straight-forward as you are hoping.   For example have you changed the spark plugs..or HT leads etc..? Replacements can sometimes be worse than the originals.  Things don't go 'out of adjustment'. That's all I'm saying.
If it were me I'd convince Richard Hutchinson..or his Welsh equivalent to work his way through ALL possibilities ....but its easier for me as he's in Derby...not sunny Wales.
 Dave Howarth's favourite ( initial ) trick is to put a load of injector cleaner in and belt it down the motorway before he lays a spanner on them!
Good luck......

(mines not even near running yet, but I'm disturbing the absolute bare minimum of stuff before I even stick a battery on it for the first time) .

[TristanC]

I’ve not changed much. I believe the dizzy and plugs were done before I got the car.

All I’ve disturbed really is the mixture.
Yes I screwed up on the idle motor and idle ecu, but they are now replaced.

And I agree - I need someone to help me through this.....

[Chris P]

I wish I could help Tris...but its out-side my area of expertise.

[TristanC]

Thank you Chris

I’ll get there. I’m still going to drive her as the main issues are resolved anyway.

The revs are settled at 800 or so now.... climb a little to 1000.. I can live with that for a little.
She does then start to climb as she warms.... to 1,300 or 1400 or 1500
Doesn’t seem consistent....
I’ve started to suspect the throttle microswitch as of about 10mins ago.....

Basically if I quickly flick the throttle spool so it more or less hits the switch... it seems to drop the revs....
I’d did test it for continuity at the start of my issues and it was fine... so I’m still not sure.
But I’m not going to start messing the screw for the microswitch.... no more fiddling from me!!

And there’s the roughness from dead cold for about 5 mins... oh well.... she starts, drives and took myself and the food last to the beach for a coffee yesterday.

Tris

---

I’ll also add that the idle screw is notchy to turn too..... it wasn’t like that when I first had her..... perhaps some rubber is jammed in there or something.....
I really hope I don’t need to remove the metering head..... sounds scary!

[Chris P]

Its a while since I've had one off. I get the impression that they either work or don't....but it does work in conjunction with the rest of the mechanism.

[TristanC]

Oh ok.

Great pics there too Chris. Nice to see Mr Westerman giving you a hand there

[Chris P]

    I wish I could post photo's like you do Tris...my ignorance of using computers is only matched by my ignorance of complicated car electrics. 

I can do cleaning, wire brushing and touching up flakey chassis coatings and mechanicals.

 I'm looking forward to the next challenge of trying to get it running, hopefully later this week. (It does help having a proper garage and a lift and lots of free time).

Andrew and Matt have been a great help in getting the car up to Derby.   

We are doing a write up with lots of photo's for the Club Mag.

[TristanC]

Sorry I missed the reply for some reason.

When I put photos up, I upload them to an external site then link them in.... the forum has a size restriction that I can never seem to meet
But if you wanted, I could help you with putting pics/vids up when you needed.

Looking forward to your next update with MGJ

[TristanC]

Alrighty.......

I “think” something is sticking..... not sure how/why the idle slowly increases as it warms though.
But here’s what I’ve found.....

If I give the throttle spool a quick flick, the revs drop.
(I had something similar before these issues when it stuck at 1,000.... a quick throttle blip brought it back to 750ish)

This tells me that either the microswitch is a bit dodgy or the throttle plates are a bit sticky?

Thoughts?

Cheers
Tris

[Nick H]

(23 Sep 2018, 18:45)TristanC Wrote: Alrighty.......

I “think” something is sticking..... not sure how/why the idle slowly increases as it warms though.
But here’s what I’ve found.....

If I give the throttle spool a quick flick, the revs drop.
(I had something similar before these issues when it stuck at 1,000.... a quick throttle blip brought it back to 750ish)

This tells me that either the microswitch is a bit dodgy or the throttle plates are a bit sticky?

Thoughts?

Cheers
Tris

Hi Tris,
          I’d go back to that shreded rubber belt getting somewhere it
should not. Is the throttle cable sticking in the outer sheath. Maybe some
rubber got pulled into the end by the throttle spool.

It could be worth checking the underside of the throttle spool as well.
 Check the shaft that holds the throttle plates. Has anything gummed 
up the shaft as it passes through the throttle body?

I’m thinking a oiled/greased part of the throttle mechanism has attracted some of
the rubber and it’s sticking.

Nick H