Hello,

finally think i got my timming right over the weekend went out for an run and DOH cylinder 1 stopped firing
if it didnt weigh as much as a small modern car it would have been in the bin


I have done the following:

Change the plug and lead / tested the current plug and both have a strong spark

Stuck my thumb in the plug hole and turned the engine by hand, there seems to be compression and fuel

Checked for free movement on the carb and checked the idle all fine

Anyone any suggestions?

It is a pinto with FR32 cam and R1 carbs

Cheers

Paul

Just go through the usual checks - work methodically.

Proper compression test,
swapping plugs/leads to see if the problem moves,
check dizzy cap etc
Clean carbs,
etc etc

Cheers

mark

could the dizzy cap have a break in the terminal that feeds that cylinder?

So i assume there is no spark at all but the lead and plug is proven to be OK. It was running ok after resetting the timing and then went off a while later. On the ingition side i guess that rules out the dizzy, coil, rotor arm etc if the other 3 get a spark. What ign system are you running? Ive had a dicky cap before, worth a try for the cost of them.

If i put it on the manifold it quite happily sparks away so dont think its the dizzy.

Running a lumination competition ignition which uses the optical sensor in the dizzy

So the plug sparks away out of the cylinder but perhaps not when refitted.


Are you sure the carbs are operating fully? I know this sounds daft, but the first run out when i put mine on and it sounded very flat (like a Subaru). I took the air filter off and noticed 2 of the carb pistons werent operating up and down when i revved it. It turned out that i hadnt seated the vacuum tops correctly. If your carbs are the same (piston fitted with vac operated diaphragm), i had to seat the diaphragm in the groove with a small amount of rubber grease (red stuff) before fitting the tops. Its been good ever since.

I know you say fuel is getting in but it was on mine as well, just not enough.

I will have a look. I took the diaphram out and refitted last night and still did the same. I Think the slide does move up and down when i rev it but may be worth taking to bits again and check everything is seating.

Would it be worth dropping the float bowl off and checking the filter from the fuel rail? I cant imagine this been blocked as i would have expected one of the middle carbs to get any crap from the inlet as this is where the fuel enters.

Mine sounded very flat and when i had a look (stuck my hand in) the exhaust running for the first cylinder wasnt even warm but the others were red hot

I found it a right bugger to get the diaphragm to seat on 2 of the carbs and then get the bowl ontop. This si why i resorted to using the red rubber grease to ensure they were seated first before placing the top on (vaseline may also work). the rubbers were just too small for the groove. Twice i placed the top on, screwed it down then pushed the pistons up (as you know they fall down themselves). They seemed to be great but as soon as i fired the engine up they seemed to unseat. After using the grease method they have been great.

Sorry - didnt observe change in exhaust tube temp but suspect it would be as you describe.


I may be way off the mark but worth a free check.

found the problem today took the float bowl off the affending carb and the mixture tube was sitting in the bottom screwed it back in and all sorted