Today I decided to try to a bit more to *improve* Alfenia's health. I decided to double check any work that was recently performed by an AR mechanic, as I have zero faith in their abilities
I decided to check the spark plugs as they had been replaced at 60k miles by an AR garage
I removed the top engine cover & the the Spark Plugs HT pack & leads. Opening some of the spark plugs was too easy, they had not been properly tightened. So there could have been a loss of compression.
Large plug type: NGK BR6EKPA x 4
Small plug type: NGK PMR7A x 4
So far so good............
As I inspecting each plug the gap I noticed the gap seemed to be very wide. Measuring each gap they ranged from 37thou to 42 thou, almost 1mm
Each plug look dirty both around the thread, were the burnt compressed air was escaping & the tips were too. I now suspect that these plug were never replaced, or possibly only 2 or 3 of the 8 were. Using a wire bush i cleaned up all surfaces of the plug. I re-adjusted the gap to 30 thou, on all 8 plugs.
I then inspected the hT packs & leads. Each lead read 1.7 kilo ohmns, which is fine. Inside the long leads, that are on flexible leads, there was a build up of brown coloured gunk so i sparyed WD40 into the hole. Using a q-tip/cotton bud i removed all the gunk.
RESULT: Went for a test drive, definite improvement. I even felt an extra surge of power at around 6000 rpm in 1st & 2nd. Previously i always felt Alfenia power was too linear at approx 6000 rpm.
1. Can anyone tell me the correct gap distance for each type of plug?
2. In Ireland where is the cheapest place to buy these plugs, i think they will need to be replace.
3. Has anyone else seen similar issue to mine caused by *crappy* plug leads or in-correctly *gapped* plugs?