Messages

1

Mk IV, Superblower, CRS and other Continuation Cars Forum / Re: MKIV Engine Problems

« on: June 20, 2019, 17:10:27 »

.
Martyn

Many Cobra Owners experience problem with too high a CO2 reading,  but usually get a pass if they let the Cats get really hot, the CO2 readings reduce and mot pass certificate given.

That is assuming you are running Cats and a stock exhaust system.
worth going throgh Barries suggestions, then if still negative

Alternative is find a different Mot station  who appreciates older cars especially AC's and the like.
Cheers
Keith

Keith,
Thanks for your post.
No Cats on this baby !
I did get my certificate, they are very Classic friendly.
Best wishes.
Martyn.

2

Mk IV, Superblower, CRS and other Continuation Cars Forum / Re: MKIV Engine Problems

« on: June 20, 2019, 16:23:46 »

Float bowl levels too high ? Secondaries not opening correctly ? Where is all that current going ? You should not need a relay for the ignition load. Is the cooler fan relay stuck on and running full time ? Could a ballast resistor be missing from an 8 volt coil system ? That level of current is more than capable of setting the poor thing on fire so caution is advised.....
Let us know what you find.
Barrie

Barrie,
Thanks for the suggestions.
We've looked at the whole carb setup and engine man has had the thing apart a few times, ultrasonically cleaned and properly set up.
The current issue is decidedly a problem and as said one of the fuse carriers was showing signs of overheating / melting.  I've had an issue with a blade fuse melting part of the fusebox in the past so more investigation required wiring wise I suspect.
I will let you all know when we get to the bottom of it.
Many thanks.

3

Mk IV, Superblower, CRS and other Continuation Cars Forum / Re: MKIV Engine Problems

« on: June 20, 2019, 16:17:27 »

I wouldn't start tearing the engine apart for high CO emissions.  The engine is running rich.  Double pumpers are not noted as emissions friendly carbs.  I would really have a good look at that and lean it out.  I would also check out the complete ignition system and timing.

One of my friends had a hell of a time getting his completely stock MkIV (no double pumper) to pass California emissions.  I'll ask him what he had to go through.
Good luck
Bert
Danville, California

Thanks Bert,
I think the ignition system needs a good look at.
Engine man has tried some tweaks with the carburettor settings and leaning it out had no particular effect in terms of the performance issues above 4000 rpm and horsepower output.  He tried a different coil but no success there either.
I guess we'll just have to prove the individual elements and tick these things off one by one.
The mystery continues …….

4

Mk IV, Superblower, CRS and other Continuation Cars Forum / Re: MKIV Engine Problems

« on: June 15, 2019, 10:02:10 »

MJF,
Yes, completely fresh 99 octane fuel.

5

Mk IV, Superblower, CRS and other Continuation Cars Forum / MKIV Engine Problems

« on: June 14, 2019, 14:21:37 »

Hi, I'm not sure if anyone will be able to help, but all comments/suggestions gratefully received.
I'm also not particularly mechanically experienced so do bear with the description etc.
I have two concurrent problems with my MK IV (AK1259), whether they are related in any way, I'm not sure.

The car failed its recent MoT on CO output. I've had it to my local engine specialist to have the carb (4 barrel Holley 650 double pumper) cleaned / adjusted which is something it seems to need every couple of years. I understand this is due to the additives in higher octane fuels and the car getting very little use over the winter months. I've noticed over recent runs that the engine note is rather 'woofley' when cruising along in higher gears, in contrast to the previous 'bark' under acceleration.
On the rolling road we found output peaked at about 240bhp some 130/140 bhp less than peak achieved a few years ago and very unresponsive beyond about 3800/4000rpm.
Compression and leak down test of all 8 cylinders was good and within expected parameters.  Plugs were okay. Slight oil leak from the rear of one of the rocker covers noted. The engine runs quietly with nothing giving concern in terms of 'noise'. This is also confirmed by microphone / headphone examination with the engine running at load.  Engine man suggests this means it's unlikely to be a problem with cam lobes. Exhaust manifold downpipes not up to expected temperatures on a laser thermometer. Exhaust tested and no surprises there.

We've also discovered some issues with the wiring. This is causing concern with fuse holders melting and far too much current (17 Amps ?) on ignition circuit. Seems that it's wired through the ignition key and not routed through a relay.

Likely next steps will involve inlet manifold removal to inspect rockers / internals and possible partial re-wire.  All sounding reassuringly expensive ! 

Has anyone experienced similar problems ?
Thanks.

6

Mk IV, Superblower, CRS and other Continuation Cars Forum / Mk IV Heater Core

« on: August 07, 2012, 14:53:09 »

BBK, I had the heater removed from my MkIV (AK 1259) a couple of years ago while I was having some engine work done.  I never took to the Ford heater switchgear that AC used and to be honest there's so much heat soak from the engine that I'd never found the heater that necessary or useful.
   
   I think I still have the box of 'bits' lying around in the garage somewhere.  I'll have a look and let you know.
   
   Not being as technical as most of you, could you provide a photo of what you're trying to replace so I know exactly what I'm looking for ?

quote:Originally posted by BBK
   
As a continuation of my saga on getting my AK 1216 road ready, my mechanic advised that my heater core was bypassed a while back and he has taken it out of the car.  Unfortunately, it is shot and not repairable.  He knows the part number but has been unable to locate a new core stateside, and has contacted Hawk Cars and AC Heritage in England per my direction to source this part and is awaiting word from them due to the time difference.  I am hoping that the forum can advise if Hawk and ACH are the proper source for the Mk IV heater core or if there are any other sources you know of.  Also, if a member has by chance, a spare heater core that is in good shape lying about that they wish to sell, please let me know as I would be interested!  Thanks to all.
   
   My mechanic is scrambling to complete the work prior to the Monterey Historic races in a couple of weeks. I have my ticket and corral pass!  The gentleman organizing the corral at the races advised yesterday that there will be 30 original AC/Shelby Cobras in the corral and a total of 175 cars there (Shelby Mustangs, continuation and replica Cobras).  I willtake plenty of pictures and plan to post some after the event!
   
   
   

7

Mk IV, Superblower, CRS and other Continuation Cars Forum / Mk IV Heater Core

« on: August 07, 2012, 14:42:11 »

quote:Originally posted by BBK
   
As a continuation of my saga on getting my AK 1216 road ready, my mechanic advised that my heater core was bypassed a while back and he has taken it out of the car.  Unfortunately, it is shot and not repairable.  He knows the part number but has been unable to locate a new core stateside, and has contacted Hawk Cars and AC Heritage in England per my direction to source this part and is awaiting word from them due to the time difference.  I am hoping that the forum can advise if Hawk and ACH are the proper source for the Mk IV heater core or if there are any other sources you know of.  Also, if a member has by chance, a spare heater core that is in good shape lying about that they wish to sell, please let me know as I would be interested!  Thanks to all.
   
   My mechanic is scrambling to complete the work prior to the Monterey Historic races in a couple of weeks. I have my ticket and corral pass!  The gentleman organizing the corral at the races advised yesterday that there will be 30 original AC/Shelby Cobras in the corral and a total of 175 cars there (Shelby Mustangs, continuation and replica Cobras).  I willtake plenty of pictures and plan to post some after the event!