Join Date: Nov 2018
Location: March,Cambridgeshire U.K
What am I missing?
Hi all. Problem with the "Eight" a 1986 SU carburettor car. Please bear with me while I try to explain.
Took the car out on Monday for it's inaugural run this year after spending the winter months tinkering and tidying. It has been starting in the garage readily but not having been run anywhere since October last year it seemed a bit lumpy, so off we went and ,after filling up with premium UK fuel, it started and run very well with a 8 mile blast at legal A road speeds seemed to clear what I guess were slightly sooty plugs (newly installed). Made about half a dozen stops and started absolutely fine and after about a 35 mile round trip it was still a little bit lumpy at low speeds. I thought maybe carbs needed balancing so planned a trip to a RR independant specialist to get sme advice. This morning fired the car up and it ran for about 30-40 seconds before stopping and refusing to start at all. Now, the fuel pump was not making a sound so that was the first port of call, using a probe to feed the live side of the pump it ran fine,pump not engine,but not from it's own wire which is dead. Checked fuses all OK, I did check the carb filters after Mondays trip and, whilst needing to be renewed in the short term,they were not blocked, so I loosened a pipe to see if I had fuel flowing,I did but only when I fired the pump with the probe. Had a look to see if any wires had been disturbed and found nothing amiss. Next I thought I will check for a spark and lo and behold nothing, 12v at the LT ignition side of the coil switching via the key but nothing from the HT side,again all fuses OK and the car has a brand new battery and cranks over really well.
My question (s) are:-
Is it possible the spark amplifier has given up? It looks original and is a Lucas part. The car has 82000 miles under it's belt.
Does the amplifier incorporate a fuel cut off ? It seems odd that both ignition and fuel would give up simultaneously after running so well on Monday.
Are there any diagnostics that can be performed on the amplifier to ascertain it's status?
Any pointers or advice would be very welcome, thanks in advance.