Over revving and other issues

[SpudMurphy]

Tris good luck - you'll be an expert on this soon!!

For what it's worth, and it's only because you mentioned the W pipe - check that the pipe itself is seated ok - mine wasn't and was discovered at attempt #3 to start the engine.

Is Stuart popping down anytime soon?

[TristanC]

Thanks Kev,

I will need to check the W pipe...... I had already forgotten about that actually! Lol

Stuart will be letting me know when he’s available. But with Dad still in hospital, I may not have a great deal of time myself. We will see how it goes.

Tris

[Rissy]

For the "W" horns pipe, it's worth putting new gaskets on every time you open that up. Cereal packet cardboard is an excellent material to make them from (templated from originals) and actually better than the stupidly thin paper gaskets that are supposed to be used there.

[SpudMurphy]

(28 Sep 2018, 08:34)TristanC Wrote: Thanks Kev,

I will need to check the W pipe...... I had already forgotten about that actually! Lol

Stuart will be letting me know when he’s available. But with Dad still in hospital, I may not have a great deal of time myself. We will see how it goes.

Tris

Yes I read elsewhere about your Dad - I hope he takes it easy and relaxes whislt making a full recovery?

When you know if/when Stuart is coming would you let me know please? it would be good to meet up?

[TristanC]

So I discovered a vac leak over the weekend that was increasing the revs all of a sudden over 2,000!
A vac pipe near the CSI has come off. Put it back on and reduced her back to the 1,500 to 2,000 area.

Disconnected the vac pipe that comes off the solenoid to the diaphragm (I think that’s the correct one for the distributor advance?)
Anyway, that made zero difference to the revs.

Today - I’ve not started it, but inspected all the vac lines again, and they are all ok. But as Stu mentioned, it’s a good idea to replace these - so I’ll have to do that.

Then I removed the W pipe to inspect the butterflies and also the springs on them. While I was there, I created new gaskets for the pipe from a cereal packet as per Rissy’s suggestion.

Here are some pics - maybe something will jump out at you guys.... seems ok to me.

W pipe off, butterflies closed


W pipe off, butterflies fully open:


New gaskets made:



And finally, a pic of the AC compressor. This area has the highest concentration of belt rubber.
The pulley turns freely, as does the inner piece (although more resistance there, as expected)
But look at the rusty nature of the pulley...... perhaps this is the reason for the wear on the belt??


Get a load of that rubber!!!

[Nick H]

Tris,
Good work there.
Only thing I noticed. Is the full throttle micro switch working? The reason I say that is the build up of rubber dust around it. I’m not sure what effect on idle it might have if it was stuck on. It’s supposed to enrich the fuel mix at full throttle.

Nick H

[Chris P]

I assume you be replacing the two 'O' rings whist you are in there?

[TristanC]

When I manually click the full throttle switch it brings the revs down.... I guess that’s correct?

Chris P - I’ve not replaced the o-rings, they seem to be making a pretty tight seal. Well at least they made the pipe difficult to pull off and push back on.
No reason why I shouldn’t replace them. They’re cheap enough....

Tris

[Rissy]

(30 Sep 2018, 13:03)TristanC Wrote: So I discovered a vac leak over the weekend that was increasing the revs all of a sudden over 2,000!
A vac pipe near the CSI has come off. Put it back on and reduced her back to the 1,500 to 2,000 area.

Disconnected the vac pipe that comes off the solenoid to the diaphragm (I think that’s the correct one for the distributor advance?)
Anyway, that made zero difference to the revs.

Are you saying your issue is now resolved, or on-going?

When you disconnected the vac pipe to the distributor, did you leave it open at the solenoid valve, or block it off? I only ask because although the valve should only suck on the pipe going to the distributor when the idle switch is disengaged (I *think* that's right!? i can't fully remember which way around it works), if it's faulty (ageing seal or jammed - although to be fair, i've never heard of a solenoid valve going bad) then it may be sucking on it all the time. If it's not connected to the distributor, then in essence, that would provide another vac leak point too. (best to be thorough) - it's difficult to figure out what the problem is with your car from a remote location without access to the vehicle.

Another thought; is the one way valve on the CPR the correct way around? (The black/white plastic valve)

[Nick H]

(01 Oct 2018, 17:17)TristanC Wrote: When I manually click the full throttle switch it brings the revs down.... I guess that’s correct?

Chris P - I’ve not replaced the o-rings, they seem to be making a pretty tight seal. Well at least they made the pipe difficult to pull off and push back on.
No reason why I shouldn’t replace them. They’re cheap enough....

Tris

Tris,
      When I get a chance I'll check the full throttle switch on my car and see what happens. I'll report back.

I have had another thought on your issue. Have you checked the electrical connections behind the coil cover? It may be worth unplugging them spraying electrical contact cleaner on the connections and plugging them back in.


 The reason I mention this is there is a Idle speed thermistor that is installed in the 'Y' pipe situated below the intake manifold in the area known as "The valley of death" The wiring for this runs through those electrical connections behind the coil cover. I'm not sure which connector it goes to off the top of my head nor where it goes from there (ECU or Idle computer??? not sure).
 Maybe the plug has come off the thermistor or its failed or the other option is a dodgy connection behind the coil cover. 


It should be possible to check the thermistor with a multi meter if you can identify the wiring at the connectors or ECU/Idle computer without having to strip out the intake manifold.


Nick H

[Rissy]

(02 Oct 2018, 12:06)Nick H Wrote:  The reason I mention this is there is a Idle speed thermistor that is installed in the 'Y' pipe situated below the intake manifold in the area known as "The valley of death" The wiring for this runs through those electrical connections behind the coil cover. I'm not sure which connector it goes to off the top of my head nor where it goes from there (ECU or Idle computer??? not sure).
 Maybe the plug has come off the thermistor or its failed or the other option is a dodgy connection behind the coil cover. 

It should be possible to check the thermistor with a multi meter if you can identify the wiring at the connectors or ECU/Idle computer without having to strip out the intake manifold.


Nick H

Idle speed thermister is connected to pins 9 and 11 of the idle speed ECU. These two wires go through the bottom right hand side bulkhead connector (Black/Slate wire to top right connector and Black/Yellow wire to second bottom right connector)

The resistance for this should increase the colder it is, and with a cold engine at this time of year, should probably read in the region of 20kohms. Obviously, as the engine temperature warms up, this reading should drop away.

[TristanC]

Rissy - sorry no the issue is still there. But I experienced higher revs again and that was due to a loose vac pipe.

The distributor vac pipe - I just disconnected, and it was left open.

I’m not sure on the CPR - where should I check?

Nick - I’ve not checked the connections behind the coil cover recently - but I did clean them all up as one of my first jobs when I received the car. But I will check the resistance as pointed out, next time I’m looking at this.

[Rissy]

I'll admit i'm clutching at straws for giving more suggestions with this one, because i'm not even sure of the effect of having the CPR one way valve the wrong way, but it's the black and white plastic cylindrical shaped duber right by the CPR. You should see two pipes coming off each side of the CPR and these should be linked together via the valve i'm discussing, as well as leading off towards the VOD for the thermal Control Valve. The one i'm asking you to check should have the white side facing the rear windscreen (towards forwards of the car).

[TristanC]

Thanks Rissy - I know the one you mean now.
That hasn’t been disconnected before or after the issue raised its head.

I’m highly suspecting a vacuum leak that I can’t see..... I.e one of the 3 vac connections under the intake manifold :o
If one of the pipes popped off from the CSI, then it could have just as easily happened where I can’t see it... darn it.

[Rissy]

(03 Oct 2018, 13:03)TristanC Wrote: I’m highly suspecting a vacuum leak that I can’t see..... I.e one of the 3 vac connections under the intake manifold :o
If one of the pipes popped off from the CSI, then it could have just as easily happened where I can’t see it... darn it.

That IS entirely possible.  I sometimes forget that thermal control valve since my car isn't utilising it.  Mine is completely disconnected.

If there IS a disconnection or leak on that, or towards/away from it, then I'd have expected it to have given you top end performance issues perhaps, as it would effect the vacuum pull on the distributor for the advance function, meaning the solenoid would be switching.....nothing.  Potentially.  it would also effect the CPR performance.


You know, Aldi currently have inspection cameras in on offer.  £39.99.  I bought one the other week.  Nice piece of kit.  Doesn't do video, only photos, but for the money, it's quite nice.

That would make such a visual inspection a bit easier for you...