HEI

'86CJ

More info: 86 cj7 4.2 I was talking to a fellow jeeper and he said " If you don't like the Motorcraft ignition system you can change it" So I did some research and next think you know I now hav a HEI didtributor in my jeep. It works great except for two things the valves rattle on acceleration and when cranking the first revolution of the engine on the sounds like the battery is low. Futher research tells me that it's in the vaccuum advance. Does any one know about this or have info on hwo to cure it? Timing is set at 9 Deg BTD plugs are gapped at .045" vaccuum advance is plugged.

Mudrat

<t>More info: 
86 cj7 4.2 
I was talking to a fellow jeeper and he said " If you don't like the Motorcraft ignition system you can change it" So I did some research and next think you know I now hav a HEI didtributor in my jeep. It works great except for two things the valves rattle on acceleration and when cranking the first revolution of the engine on the sounds like the battery is low. 
Futher research tells me that it's in the vaccuum advance. 
Does any one know about this or have info on hwo to cure it? 
Timing is set at 9 Deg BTD 
plugs are gapped at .045" 
vaccuum advance is plugged. 
86 - 
I have an 85 4.2 with HEI, pretty much acts the same, first turn sounds bad only when it's cold. Then it catches and runs like a top, I'm around 10-11 BTDC, but she purrs nice ;-)

I'm also ported and polished, with Clifford intake/headers and Webber 38 ;-) 
Pat</t>

'86CJ

Thanks for the reply I'll try pushing the timing to 11 BTDC. What about your plugs what brand and # ? what's your plug gap? what kind of wires are you running? I running a set of HEI wires pre-cut to fit '81 Fairmontand a set of champion plugs, just stock stuff. Is your vaccuum advance pluggged? I guess that I'm grasping at straws I've tried alot of different things nothing seems to want to fix my vale-ping on acceleration. I'm running stock everything (the factory computer and wiring are removed)except the carb which is a Redline. Regards Lee

Mudrat

<t>Thanks for the reply 
I'll try pushing the timing to 11 BTDC. 
What about your plugs what brand and # ? what's your plug gap? 
what kind of wires are you running? 
I running a set of HEI wires pre-cut to fit '81 Fairmontand a set of champion plugs, just stock stuff. 
Is your vaccuum advance pluggged? 
I guess that I'm grasping at straws I've tried alot of different things nothing seems to want to fix my vale-ping on acceleration. 
I'm running stock everything (the factory computer and wiring are removed)except the carb which is a Redline. 
Regards 
Lee 
I'll have to go look, Autolite somethings ... at 45?? Whatever was recommended in the article. 
Old MC dizzy just new cup, cap, rotor, etc ... 
Wires are 8mm specials from AutoZone 
Vacuum works - not plugged

Try a higher octane gas for a tank and see if that cures is</t>

'86CJ

Thanks for the info. I'll try super gas I'll may just have to remove some of the lead from my foot! Gas in my is down to $1.95 for regular unleaded. Never thought that I would say that $1.95 was cheap but it's in the conditioning!

Mudrat

<t>Thanks for the info. 
Gas in my is down to $1.95 for regular unleaded. Never thought that I would say that $1.95 was cheap but it's in the conditioning! 
Aint that the truth - we're "down" to $1.98

Pat</t>

Ted Wendel

Try a stronger set of springs on your mechanical advance.

LEVE

More info:
86 cj7 4.2
I was talking to a fellow jeeper and he said " If you don't like the Motorcraft ignition system you can change it" So I did some research and next think you know I now hav a HEI didtributor in my jeep. It works great except for two things the valves rattle on acceleration and when cranking the first revolution of the engine on the sounds like the battery is low.
Futher research tells me that it's in the vaccuum advance.
Does any one know about this or have info on hwo to cure it?
Timing is set at 9 Deg BTD
plugs are gapped at .045"
vaccuum advance is plugged.

If the vacuum advance is a worry, the you can also use a Crane Adjustable Vacuum Advance fro the GM HEI for about $23.

'86CJ

Thanks for the info. I'm down right now (bad trans) but as soon as I get back to running. I will try the adjustable vaccuum advance. Lee