620 electronic ignition questions?

[machowgn]

Hello All,

I recently installed a dizzy in my 74 620 pickup truck, thanks for all the help

from heinz & frank and everyone else on the correct way to install the dist,

However here is the latest issue, everything is great untill the L-18 warms up

then it pops like it's missing? any suggestions? also i have a question about the water line comming off the lower radiator hose/heater hose that routes itself to the intake manifold? would that cause any problems? if it was leaking

internally? I don't belive mine is but just curious what that does? thanks,

Machowgn.

[datzenmike]

Water actually flows out of the head and along under both intake runners and out beside the carb and down to the inlet to the block. The purpose it to warm the intake to help vaporise the fuel.

 

It actually pops? Do you have a good new cap/rotor/wires? You have a hotter spark so old coil or plug wires might not be able to handle this. Check the valve lash.

[banzai510(hainz)]

tell us what exactly you did?

evertything

what you changed or didnt change in the truck

 

coil? ballast? ect.. and what was in there.

 

why would it leak water? was the intake changed

[Pacific coast Datsun]

Id replace the plugs & re gap them to .044. You now have a hotter spark like Mike mentioned. Popping or missing sounds like a timing issue.

[ggzilla]

Timing problem. Use a timing light (disconnect the vacuum hose while checking).

[Guest jaimesix]

I had a problem with a distributor that took me a long time to realize. The dizzy had dist shaft play. While driving, the movement of the shaft would make the car miss, even stop the engine momentarily.

 

Like Banzai says, better to list everything that was changed and everything that remained connected ignition wise.

 

Try it simple, try a timming light and properly disconecting the dist vac hose at the distributor as mentioned by Ggzilla . If it does not help, start writting down the list of parts.

 

Jaime.________________________________________________________

[banzai510(hainz)]

The dizzy had dist shaft play??

 

more likey on a point dizzyI had this happen and LOT of POPPING!!!!, Not as noticable on a EI type

[Guest jaimesix]

The dizzy had dist shaft play??

 

more likey on a point dizzyI had this happen and LOT of POPPING!!!!, Not as noticable on a EI type

 

 

Yes, it happened on my RHD postal jeep. It had electronic ignition. I replaced the factory distributor for a rebuilt one a few mos after getting the jeep, while tunning it. ( mistake, if it ain't broke, do not fix it.)

 

For years I wondered what the heck was happening.....it would stop upon driving over a hump....die while at high speed on freeways upon a bump.....( restarting it immedialte was fine ) I was puzzled.:confused:

 

Changed cables, plugs , caps , rotors.....ECU....needlessly.

 

Later when I got my cyl head out for a perf rebuild ( clifford 6 into 2 into one headers....MSD ignition...MSD distributor...Weber carbs....etc..) the problem was gone. But I realized the problem was gone upon changing the distributor.

 

Carefull dissassembly of the distributor found excesive play on the shaft ( vertical play )

 

If there is vertical play, the shafet moves, and the spark misses.

 

I guess it is not common, but happens. Cheap dist rebuild though...( Kragen's )

 

:cool:

 

Jaime._________________________________________________________

[machowgn]

Thanks for all the tips, heres is what I found: I used a new msd blaster 2 coil

new 7mm plug wires, new plugs, gapped at.041" I bought a " new " suppoedly

matchbox type dizzy. I installed the dist, with # 1 cylinder at 0 on the crank mark, compression stroke, # 2 cam lobe striaght up. fired up the motor, tried

to adjust the timing 12-15 deg. advanced, once the motor was warmed up started to miss, no matter where I put the dist. I even tried loosening the 8 mill. bolt for for more advance, still no good. I scoped the motor, found at Idle the rpm's read around 4000? I then tookoff the dist cap and inspected the shaft for end play, and sure enough, it moved around pretty good, Now

I compared that dist. with a spare dizzy I purchased from frank, thanks again!

also with the the help of Heinze over the phone I was able to track this down. I did do one other check. With the motor running I pulled off plug wires, one at a time, now I had done a compression check of this L-18 beforehand, and it has only has 67k on it, not bad for a 74 4x4 conversion truck! 180 psi thru all

cylinders! When I removed the plug wires from cylinders # 1 & # 4 hardly no change in idle, the other two made significant changes in the rpm's. Now I think I can probably look into valve backlash when the engine is cold in the morning I'll adjust them and see what happens, anybody have any thouhgts on this? thanks.