engine issue my specialist can't fix ... help!

[Jonny XKE]

My series 1 4.2 which is 1000 miles out of a full nut and bolt rebuild is suffering a fault my local XK specialist Rhave been unable to rectify. Under load the car hesitates badly and misfires. The carbs had muck in them which they originally thought was contamination from the fuel tank but it wasn’t. They put other carbs on and its not the carbs at fault. They now found water condensation coming out of the breather causing contamination in the carbs. They removed the cylinder head and re skimmed to see if that would stop the water in the breather pipe. This didn’t work. So they have disconnected the breather and they said that it would run smoothly until they come up with a solution for the water. After driving it back today from them I was dismayed that the same problem is still there. I'm at a complete loss and so is my sepecialist

[christopher storey]

It may be harsh to say it, but your specialist doesn't sound as though they know what they are doing . Was there a loss of compression ? How much "water" was coming out of the breather so as to justify removal of the cylinder head ? If there was that much, then one would almost certainly have been able to see contamination of the oil ( it goes milky ) . Furthermore, I cannot see how water can get into the carburetters from the breather : it can get into the inlet airstream, but not into the fuel supply, from that source. Also,are the needles correct, and correctly set with the shoulder set flush with the base of the piston ? Are the float levels correct, and are the floats and needle valves in good condition? In addition , bearing in mind the old adage that 99% of SU troubles are in fact down to the ignition system, one would think that any specialist with experience would at least have made checks of the ignition system before embarking on major engine work . . The start of a breakdown in any one of the following components can produce the symptoms you suggest: condenser ; points ( or ignition module if electronic ) ; rotor arm ; coil ; ignition HT leads . Also, any slippage of the ignition timing may have similar consequences

It would be interesting to know what a check with a vacuum gauge on the inlet manifold would reveal - these are an incredibly useful diagnostic tool


PS It also occurs to me that if there is excess water coming via the breather housing, a potential source of this is perforation of the front cover in the area immediately behind the water pump impeller : the metal in this area frequently erodes and becomes porous even if there is no overt hole ( but as I have already said I would expect such a fault to contaminate the oil visibly )

[mgcjag]

Hi Whats your name........totally agree with the comments made by Christopher above......I would be seriously concerned about your Specialist........are you competent to work on the car yourself or would reccomendations for a proper secialist be more suited... Steve

[Gfhug]

I heartily agree with Christopher and Steve. A brief search for Rhave didn't show any "XK" specialists, maybe I missed finding them. I suggest you tell us which part of the country you live and then, perhaps, one of our more knowledgeable owners could have a look at the car and/or suggest a recognised specialist who is close enough to help.

Geoff

[Heuer]

Could be the inlet manifold has become porous or ruptured. The cylinder head can also become porous. Is there excessive water coming out of the exhaust? By excessive I mean dripping from the tail pipe. You need a engine specialist!

Take it up to Angus Moss in Letchworth if you are based in London.

[Jonny XKE]

No loss of copression
Not much water around a thimble every 10 or 20 miles
The oil isn't milky at all and there are no signs there.
The SU's were professionally set up 1000 miles ago
Everything on the car is new or restored.
I think you are right I need to change specialist. My feeling is ignition/ timing, although I'm not technical

[Jonny XKE]

Hi Whats your name........totally agree with the comments made by Christopher above......I would be seriously concerned about your Specialist........are you competent to work on the car yourself or would reccomendations for a proper secialist be more suited... Steve

recommendation would be good .. Near Exeter but will travel

[Gfhug]

Jonny, unlike other forums there is no need to use the quote function, you'll notice others don't. It can be useful if you are referring to a much earlier post, but even then you can edit it down to just a sentence or two.
It takes up valuable server space.

John Burton of the Jaguar Driver's Club is in the south, maybe you could contact him via the club?

Geoff

[mgcjag]

Sorry i dont have a reccomendation for that area....any one in the area that can help.....Steve

[Jonny XKE]

OK thanks for all the comments. Very helpful. I do wonder whether it needs to be a XKE specialist. Its an engine after all .. there is a local classic car garage who do race classics and have an excellent reputation but not specifically XKE's. I'm wondering whether to ask him to do a diagnosis on it.

[Heuer]

I do wonder whether it needs to be a XKE specialist. Its an engine after all ..

John Burton is in the Hampshire area. T: 02380 644179

[Jonny XKE]

Thank you...

By the way it has a Mega jolt electronic ignition system and Mangoletsi cable throttle conversion .. I wonder if this is anything to do with it as they said that they werent familiar with it

[christopher storey]

If your local racing connection has a rolling road and/or an analyser like the old Suntester or similar machine, then they are probably your best bet . You really need to get the ignition analysed as a start and an oscilloscope based tester is probably the best for that , and even if they do not have one of the complete old style machines, , a laptop based oscilloscope and a cheap vacuum gauge will give invaluable information. as will an infrared exhaust gas analyser , and most people who do tuning now have these

PS a thimbleful of condensate every few minutes is nothing to worry about ; I cannot really see how the mangoletsi could cause a misfire , but the megajolt may well be a candidate as a cause

[Heuer]

Ahh - Megajolt - now you tell us! Superb system but have you made sure to fit BPR5 'resistor' spark plugs. If you have standard plugs there is a high probability of a misfire.

The reasons/research that went on into this can be read around about this post in the Megajolt support thread:
viewtopic.php?p=22140#p22140

If they are not resistor plugs it will only cost you about £12 and 10 minutes work to see if it resolves the problem.

[Jonny XKE]

Thanks Christopher .. someone else said that may be the case.

The garage is http://www.tiptongarage.co.uk/

They have a rolling road

[Jonny XKE]

David .. I hope you are right. I have just spoken to the garage and they fitted normal spark plugs. Now trying to get a new set before my trip in it to France tomorrow night!

[Heuer]

They should be easy to find at a motor factor or Amazon can deliver tomorrow. They are add on items so you need to buy something else to take the order over £20.

[Jonny XKE]

You are a star David .. ordered just now and will be with me tomorrow by 1pm ready for my trip. I will be so pleased if it is the reason, but equally annoyed as I have had all this work done for no reason. Will let you know how I get on. Thanks again

[Heuer]

Good luck.

Make a note of this web site before your trip: https://www.google.com/maps/d/viewer?mi ... 999805&z=6

A brilliant Interactive touring map that not only lists restaurants, hotels, places to visit but also specialist classic car garages in case you get into trouble. It was created by an E-Type owner and Forum member Hubert. Also the Forum will help out if things go awry. Enjoy your trip.

[Jonny XKE]

Thats brilliant thanks a lot.