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I'm begging... please help me trouble shoot this

I do have a pretty good ear for it, although it has been a while. My first car i got when i was 14 and I spent all my time experimenting with it until it ran as good as it possibly could. I had a points distributor in that car though, and spent many nights making fine adjustments to the point gap and then seeing what difference it made. I put about 400 miles on that car before i ever got my license, all at night, and all to my neighbors annoyance. :D

Rene
 
Several people have suggested a vaccume leak, I really really don't want to accept that because I just put some $15 gaskets on there and filled her up with coolant. I don't see how I would have a vaccume leak, I put a thin bead of RVT around all the ports, and an RVT bead at either end of the manifold.

Would a vaccume guage detect a vaccume leak? If so, what would it be reading?
thanks,
James
 
I'm still a little confused on the vaccume advance. We've established that idle and low RPMs are currently BETTER when the dizzy is hooked to the FULL vaccume source.. So does a vaccume advance literally "advance" the timing, or does the vaccume advance "retard" the timing progressively? If it advances the timing, then i suppose I definitely need to advance my timing (turn the dizzy counter clockwise), right?
I'm gonna finish a bit of homework and go outside and see what I can do.
thanks,
James
 
Just be sure that your vacuum advance is disconnected (and the hose plugged) when you're setting your base timing.

If you set the timing with the vacuum advance hooked up, then that's your problem right there.
 
cool, that's what I was thinking. So I'm gonna leave her hooked to ported vaccume and advance that sob untill I hear pinging :wink1:
 
goldwing2000 said:
Just be sure that your vacuum advance is disconnected (and the hose plugged) when you're setting your base timing.

If you set the timing with the vacuum advance hooked up, then that's your problem right there.
Click to expand...

I was replying to Paul with that last post. I always set the timing with the carb plugged and the dizzy unhooked.
thanks,
James
 
read this I found to tell ya in simple terms why you want it on a ported source to advance at light loads under cruise conditions :

VACUUM ADVANCE AND WHY YOU WANT IT FOR YOUR CAR

An often-asked question from many callers relates to whether they really need a vacuum advance mechanism on their distributor. I think this question stems from their observation that many "high performance" distributors do not incorporate vacuum advance and the resulting implication is that it is not desirable or necessary for a "good" ignition. There are a handful of applications where vacuum advance is not of significant benefit:
1) Pure racing engines
2) Severe duty very large trucks
3) Constant speed and load applications (airplanes, generators, pumps)

Other than the above, for normal automotive applications the vacuum advance will benefit the engine as follows.
1) Improved idle cooling
2) Improved idle quality
3) Improved fuel economy
4) Improved throttle response
5) Improved drivability
6) Enables improved spark knock control under full throttle accelerations
7) Enables leaner fuel jetting at light load to further improve fuel economy.

The basic reason for all these improvements is that the vacuum advance mechanism allows the distributor to supply a more optimum spark timing proportional to the load and speed output. Without the vacuum advance the distributor can only vary spark timing in proportion to speed and ignores its need for approximately 20 additional degrees of spark timing ("advance") at light loads: (idle and cruise conditions)

The basic reason for the change in optimum timing at light loads is that when operating at light loads, the mixture is leaner for fuel economy and less dense because of light load. These conditions cause the charge to burn slower, and thus, to reach peak pressure at optimum point in the cycle, the spark must be initiated earlier. Failure to do this will result in "retarded" spark timing and all the aforementioned losses.

All engines are different, and have different spark timing requirements, but they are all the same in that as load is decreased, additional spark timing is required for optimum combustion.

Do yourself a favor - 1) make sure your distributor has a vacuum spark system and 2) experiment to find out what your engine "likes" for timing at idle, light load, and heavy load. Then change the vacuum can to achieve a result closer to the optimum.
​
 
78Suburban said:
I was replying to Paul with that last post. I always set the timing with the carb plugged and the dizzy unhooked.
thanks,
James
Click to expand...

Just making sure... ;)
 
Despite the name vaccum advance, applying vaccum to the canister actually retards the timing, it does not advance it.

Then, when your engine is under load, and therfor has far less vaccum, and needs more timing, the vac canister will disengage, and advance your timing.

This is why GM runs their dizzies off ported vaccum, so they are not retarding the timing at an idle, like they would with a straight manifold vaccum source.
 
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yeah, I was thinking that I read somewhere it retards the timing? so is my timing actually too advanced initially, and I need to retard it a bit more?? I'm soo confused.. I think I'm just gonna go out and start screwing around with it and hope nothing goes kaboom in my face...
thanks,
James
 
advanced to 14, ran badly, retarded some, and now #1 PLUG WIRE DOES NOT EVEN LIGHT UP THE TIMING LIGHT!!!the others will, but not #1.. :mad:
 
I've gone insane....

swapped in a different plug wire , but #1 cylinder still DOES NOT even light up the timing light.. the others will. For kicks and giggles, I threw the inductive timing light on #6, and it was reading right at 5*BTDC.. I don't know what the timing really is right now, cause the light won't even flash on #1.. and the engine runs with a miss... #1 plug also looks a wee bit fould to me
1deadcylinderfouldcrapplug.jpg


like the electrodes are freakin coal.. I hate my life.. what in the world is killing #1? should I try to swap back in my other dizzy? I just don't understand... any tips for cleaning the fouled plug... any ideas on why this motor won't run correctly?
thanks,
James

PS: I just pulled #6 plug wire, since I knew it was firing.. its RICH too.....the q jet on the truck before this made them look the exact same way (a different set of plugs).. I know my choke is disenguaged on the e brock, cause its manual.. and I've only run it like 10 minutes and they are this FOUL!!!! why?
 
I put a screwdriver in #1 plug hole when the tab said 0*TDC.......... and the piston is at top.. so I don't think the marks are off... I just don't understand why it is foulding plugs and missing so badly... I'm really at a loss..
thanks,
James
 
SierraClassic said:
Despite the name vaccum advance, applying vaccum to the canister actually retards the timing, it does not advance it.
Click to expand...

so when there is vacuum applied to the canister it pushes against the pickup causing it to spin clockwise?

the last I knew the vacuum advance was supposed to be hooked up to a manifold vacuum source. but what do I know. :whistle:
 
TTT... I think the vac advance goes to ported vaccume, right???
Any body got any ideas.. is it possible for a timing problem to make fuel not burn correctly and foul all the plugs??
thanks,
James
 
I'll explain this how I understand it. though I may be wrong on this - always possible.
time the engine with the vac. advance disconnected. if it has a stock cam then what stock specifies for timing or if an aftermarket cam go by the manufacturer's specs.

then hook up the vacuum advance to a manifold vacuum source. at idle and high vacuum(low load) the timing will advance. under load/WOT(low vacuum) it will not advance as far the reducing the likelyhood of pinging from too much advance. but there is also a mechanical advance that will advance with rpm up to a certain point.

if the timing is right and it's still burning rich and all the plugs are gapped correctly and firing(i.e good wires/cap/rotor/module/pickup) then it will be the carb.

going back to your "edelbrock swap" was it just a carb or was it a carb and intake? what carb? is the idle mixture set correctly?
 
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