JAAAG - I helped try and start a friends XJ6 series 2 4.2

[goodwoodweirdo]

Hi guys,

Need some advice, I helped try and start a friends XJ6 series 2 4.2 ’79 vintage….

He’s just spent a fortune having it serviced and set-up. It then ran fine when he parked it up about 2 months ago, now she just won’t start ! its catches on the first turn of the key, then dies as if the fuel pump doesn’t work ! so I checked the following: Fuel pump and fuel supply OK. Tried with easy start, same result. Checked for sparks OK. Checked the pistons fell easily in the carbs OK, added a little extra dashpot oil (did seem empty). Tried with the carb piston tops open and also screwed down. I did find a pipe from under the carbs (green) not connected to a pipe from the engine, however this was a loose fit I tried with it reconnected, not connected, with me blocking the ends (maybe a pressure recirculation system)….

OK so now I’m thinking it’s the choke, I know the garage have replaced the AED once.


However if it is the AED or a air leak, wont the engine at least fire and stay running ? bearing in mind I sprayed a decent amount of easy start into the carbs with pistons up ! and still had the same results… On a carb car is there anything electronic which could cause this ? (btw no alarm)

It’s a typical story of being stored at a relatives house, they want the garage back, the car fills the whole garage and we cant push it out….

Thanks in advance

Matthew

[skeggysteve]

goodwoodweirdo said:

Need some advice,

easy start

Do not use easy start.

...............

On a serious note think logically (sp) have you got fuel, compression, spark, etc.

Just think don't guess, if you were closer I come and help.
Getting an engine started is not that hard just think and check the above.

[Pigeon]

Has it got a ballasted coil? If the ballast resistor was buggered (or the associated wiring/switching) it would fire while the starter was engaged and die when you let go of the key.

[niagra]

2 months laid up, could well be stale fuel

[tr7v8]

If i won't run on Easy start (nowt wrong with it incidentally) then it sounds like you are loosing the spark. I'd suspect ballast resistor or ignition switch. Try running a fused lead from the battery +ve to the +ve of the ignition side of the coil. These are pretty simple generally. The AEDs & the thermoswitch for them does give trouble but if it won't start on easy start then it is unlikely to be that.

If the above doesn't work then you need to start seeing whether you loose the spark or fuel.

[bigblock]

skeggysteve said:

goodwoodweirdo said:

Need some advice,

easy start

Do not use easy start.

...............

On a serious note think logically (sp) have you got fuel, compression, spark, etc.

Just think don't guess, if you were closer I come and help.
Getting an engine started is not that hard just think and check the above.

You could do with following some of your own advice about thinking not guessing. If you read the OPs post properly then you would see he has already checked all of your above suggestions. However I am sure he found your post very helpful and not at all patronising.

[richw_82]

tr7v8 said:

If i won't run on Easy start (nowt wrong with it incidentally) then it sounds like you are loosing the spark. I'd suspect ballast resistor or ignition switch. Try running a fused lead from the battery +ve to the +ve of the ignition side of the coil. These are pretty simple generally. The AEDs & the thermoswitch for them does give trouble but if it won't start on easy start then it is unlikely to be that.

If the above doesn't work then you need to start seeing whether you loose the spark or fuel.

Does it keep running if you keep the key in the start postion? (don't try it for more than a second or so, and don't rev it or its bye bye starter motor.) If so, the ballast resistor or the ignition switch is bust.

Check at the side of the coil (under the carbs) there should be a square ceramic block with two terminals attached to it. Disconnect the leads to the terminals, and connect the leads together. Job done; ballast resistor bypassed. If it still misbehaves look to the ignition switch.

Let us know how you get on!

Rich

[guru_1071]

dont those jags have a fuel pump that only pumps fuel when the car has oil pressure?

if the oil switch is faulty the pump wont kick in and the car dies

this caught a mate of mine out recently - his problem was compounded by the fact that the owner had fiddled with the relay so that the pump would only work when the ignition was off, but as there was no power it wouldnt work!

took some sorting out!

[richw_82]

guru_1071 said:

dont those jags have a fuel pump that only pumps fuel when the car has oil pressure?

if the oil switch is faulty the pump wont kick in and the car dies

this caught a mate of mine out recently - his problem was compounded by the fact that the owner had fiddled with the relay so that the pump would only work when the ignition was off, but as there was no power it wouldnt work!

took some sorting out!

Series 3's definitely had it but I don't know about the series 2. Short of the inertia cut off switch being tripped, usually as soon as you get ignition lights the pump is running. At idle you should get around 30 seconds (maybe a bit more) out of the fuel in the float bowls anyway; which isn't consistent with dying off more or less straight away.

There are ways around the pressure switch; like altering the wiring into the fuel tank switch in the dash, or just earthing the wire off the switch to the engine block.