Giulietta still runs fine with #1 lead disconnected ??

[Storm_X]

OK i installed bigger cams had nothing but problems. Reinstalled the 10548s and now the car runs better compared to the bigger cams, but there still are a thew problems.
They consist of ; #1 lead gets disconected and it still continues to runs as it did connected?, sluggish acceleration until past 2500rpm, back firing and popping during cruising speed 50kph.

Does anyone know what the problem could be ??

Thanks Chris

[Colin Byrne]

you've probably fouled the no. 1 plug when the lead got disconected and now it won't fire even when the lead is reconnected.  Running on 3 cylinders would explain all your symptoms.  New plug in no.1 and i'm tipping it'll be game on.

[Storm_X]

The lead still gives spark but i think the plugs sh*t its self. New plugs was #1 on my to do list tomorrow.

Thanks and ill see how it goes.

[Storm_X]

just put in 4 brand new plugs and still the same problem. The car feels like its kicks into all 4 at around 2500rpm.
Spark is getting to the #1 plug but #1 spark is very poor compared to the rest, the rotor button and dizzy cap are pretty much brand new in very good condition.

[Duk]

Double check valve clearances.

[Colin Byrne]

dodgy no.1 lead? try swapping leads over and see if the problem follows the lead

[vin sharp]

Back to basics; just check that your plug leads are in correct order out of the cap 1, 3, 4, 2....
#1 being the one the rotor points towhen the front camshaft lobes point to the outer edges of the head at TDC.

[Frank Musco]

Give the old girl a compression test. Take you 10 minutes and then low compression is taken out of the equation, and you know it's not too serious. I suggest this because it sounds like it comes good after 2500rpm where the cylinder has enough flow to overcome low compression. Also could relate it to a slightly blocked carby for N.o 1, so as airflow increases the blockage is overcome??

Could be a crack in dizzy cap around N.o 1? Sometimes hard to see.

[Evan Bottcher]

I know someone else asked this but... did you redo the valve clearances when you changed the cams?  If they are too tight I'm sure you'd get poor running at low rpm, but would run find at high rpm.  Low compression if valves aren't fully closing.

[Duk]

Everyone's given some good, helpful tips here.

The order of simplest to more involved would be something like:

Check plug leads are going to the correct plugs.
Check plug lead conditions (run the engine at night).
Check distributor cap condition.
Check valve clearances. Riding valves (valves that don't fully close) cause lots of fun, especially at low load.
Compression test only if valve clearances are correct or definitely not riding.

[giulia_veloce]

Check the idle circuit on No 1

Remove idle jet and idle mixture screw and blast in both directions with compressed air.
Get engine running, = operating temp.
Screw and unscrew idle mixure screw and evaluate.
MOST times,fouled spark plugs can be unfouled by jumping the spark from the leed to the plug about 10mm at about 2500 rpm.
You have to start with the basics.
Worth a try.

Robert