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Misfiring
Posted: Fri May 06, 2016 8:18 pm
by Mad Mart
I started XJX up this evening, as I'm supposed to be taking it down to the sprayers tomorrow, for some final fettling & MoT test. After a long crank (about 10 seconds) it burst into life. Haven't started it for a couple of weeks so that's not bad. I had the engine running for about 20 minutes and then switched it off because I wanted to take Dolly off it's dollies. Once XJX was on the floor (for the first time in a long while) I went to start it up again. Strangely the engine didn't want to fire and started backfiring through the exhaust. When I eventually got it to start it was only running on 2-3 cylinders so, obviously, didn't stay running for long. I know it's fairly low on fuel so I checked the float chambers but they both contained fuel. The only thing I can think of is the leccy ignition I installed (Powerspark from Simonbbc). I can't put points back in as I don't have an original dizzy cap.
Re: Misfiring
Posted: Fri May 06, 2016 8:42 pm
by Mahesh
Check spark plugs, in case the electrode has broken.
Re: Misfiring
Posted: Fri May 06, 2016 9:45 pm
by tony g
Why cant you use the same cap and rotor youre using already, but with points? I had a failed unit from them which was replaced
Tony
Re: Misfiring
Posted: Fri May 06, 2016 10:04 pm
by soe8m
Change the plugs.
Jeroen
Re: Misfiring
Posted: Sat May 07, 2016 4:27 pm
by Mad Mart
I changed the plugs but that made no difference. Thanks to Tony I then reverted to using points which has done the trick. I then proceeded to drive it to the sprayers. I had driven a couple of miles when it just gradually died & didn't want to start again. Check fuel, sure enough, no fuel in float chambers. I few people stopped to ask if they could help but I said I need a tow and didn't have a rope. One guy said "I'll pop home and get a rope and if you're still here when I get back...". A couple of minutes later a young guy pulled up in a Skoda VRS and he hade a rope and was willing to tow me to my destination, about a mile away. As I went to get in my car the other guy turned up behind me with his rope.

After thanking him we made off for the spray shop. XJX is now at the sprayers but I didn't have time to whip the pump off as the sprayer had to get home. The saga continues.
I was rather pleased at how many people stopped to ask if they could help.
Re: Misfiring
Posted: Sat May 07, 2016 6:47 pm
by Jon Tilson
Pin hole in one of the fuel line rubbers?
Jonners
Re: Misfiring
Posted: Sat May 07, 2016 7:32 pm
by Mad Mart
Possibly Jonners. I'll check the pump first just in case it has broken like the last one did.
Re: Misfiring
Posted: Sun May 08, 2016 6:40 pm
by Richard the old one
I had a pin hole in the metal petrol pipe, which cause a similar problem and this took me some time to find.
Re: Misfiring
Posted: Tue May 10, 2016 3:38 pm
by Mad Mart
Sorted. When I went to see Jon yesterday, he said there was a pool of petrol on the floor under XJX when he came in in the morning. He showed me roughly where it was and I found the problem straight away. It was a jubilee clip on the join under the passenger side which was loose. After a fair bit of cranking it started.

Re: Misfiring
Posted: Tue May 10, 2016 4:36 pm
by dursley92
Had a very similar experience when I took my car to the paint shop and that turned out to be the rubber hose inlet on the fuel pump had cracked. It was not very old and looked OK until you took it off and examined it closely. The car died on the way home but only because it had run out of petrol. The gauge was not working at the time just to confuse things.
Must be something to do with going to a paint shop?
Re: Misfiring
Posted: Tue May 10, 2016 7:29 pm
by Carledo
It's a well known fact that cars go wrong/break down/run badly after being in the paint shop.
Its because they are left standing for long periods and only fired up to move 10 feet - on full choke - then switched off before warm. Even moderns don't like this treatment! Plugs get fouled and bores get washed, but it has ever been thus and I suspect it will not change.
Steve