bushrider

i am the new owner of A 1979 toyota pick up 4x4, the truck has ran but has been verry irratic, it will be fine for a while then start cutting out and stalling, i changed the cap and rotor, wires, new plugs which i gapped, changed the coil out and it has a gm module that you would find in a v8 distributer which i also changed, set the timing, put a brand new webber carb on it , i have checked for vacume leaks over and over. the truck will sit their and idle fine, everything is great , rev it up and it revs fine, its only when the rev comes back down to a idle that evrything cuts out for about a second then goes back to its idle, i havent been able to figure this out and its getting expensive.

if i have a timing light hooked to the #1 cyliner or any cylinder for that matter when the engine has its miss the timing light stops flashing the light which makes me think it electrical.has anyone ever had this problem? is there a brain box or a igniter that could possibly couse this? any way to test them?

1stgenboy

The fact that the timing light cuts out tells you clearly that the problem exists in the ignition sysytem. Check for proper grounding. I know when I was having problems with my ignition system everything tested OK even when it was not working. I picked up a known good dizzy and no more problems.

1stgenboy

bushrider

yes, i beleave it is ignition related, i have cleaned all grounds all ready. by dizzy you mean distributer? i have takin mine off and checked everything over, i do not see anything wrong with it, the mechanical advance is working fine. do you think changing the pick up in the distributer will do anything for me?

also there is a module on the fender wall , it looks like it has resently been replaced. do you think this could be cousing my problem?

1stgenboy

Either could be your problem. If you have a volt ohm meter there are a few simple tests for both the distributor and the ignitor in the books. I think there are links to online manuals at the top of the forum.

1stgenboy

bushrider

well i found the problem, theres a short in key ignition, also in the wire going from the key switch to the coil,i ran a jumper wire from the pos post on the battery to the pos of the coil and everything works great, problem goes away. thanks for the help though!

myyota

Its common for the electrical part of the ignition switch to go bad and cause no start issues or other electrical problems like your having. Replacing the electrical part of the ignition switch will more than likely fix your problem.