[ElCamino70SS]

Hi everyone!
I'm about to take my camino project for its first spin around the block.
Ive dropped a 396 in it and a th400, some custom suspension and some new interiors. I've had the car for almost 3 years now and never driven it...!

I'm really close now but I've been having some problems lately with the engine not running on all cylinders.
I set the timing the other week at 16 idle, 36 total and it ran great!

Then when I started it up again for a testdrive and it ran really bad.
Checked all the plugs with this kind of tool that you put on the cable.
I found out that cylinder 1 had a really weak spark!
I swapped the spark plug and the cable and it didn't do any good.
So I guess it has to be the distributor then..?

Took of the distributor cap and found grey spots on the brass surfaces and thought that I had found the problem.
Got most of grey surface of with some sandpaper and put it together again, but still having the same problem! Weak power on cyl 1!!
By the way it's one of these electronic distributors...

Anyone got clue?
Should I just buy a new distributor?

 

[Tom Mobley]

take out the #1 spark plug and inspect it. compare it to one of the good ones. look for wet or black deposites, check the gap, inspect it carefully for cracked porcelin on the exterior part.

 

[JWagner]

Does it miss at idle? If so, use a squirt bottle to wet the exhaust manifold at each port to see which is the cold one. This will narrow the search a bit.

 

[ElCamino70SS]

Yeah it misses at idle, but im pretty sure its cylinder 1 that doesn't fire properly.

I've tried to change both the spark plug and the cable.

If I end up buying a new distributor, will just the cheapest "summit" one do the job or should I go with a more expensive MSD or something?
The one I have now is a GM electronic one, says Delco Remy on the cap.

 

[swcash]

A faulty distributor will usually affect all of the cylinders. If the cap, wire and plug to that cylinder check out ok, Try a compression check.
When you witness the weak spark, are you holding the spark plug wire to the spark plug or to the engine block?
If the spark is ok to the block, but weak to one cylinder plug, the problem lies with the plug or something internal to that cylinder.
Squido

 

[ElCamino70SS]

A faulty distributor will usually affect all of the cylinders. If the cap, wire and plug to that cylinder check out ok, Try a compression check.
When you witness the weak spark, are you holding the spark plug wire to the spark plug or to the engine block?
If the spark is ok to the block, but weak to one cylinder plug, the problem lies with the plug or something internal to that cylinder.
Squido

I checked the cable with a tool that you clamp around it.
When running the engine you can tell how much power that goes through the cable. Cyl 1 is weak and not constant.

It can't really be bad compression, cause sometimes it fires up good and runs nice. But then when I start it the next time it has the same problem again. Black smoke and backfires on throttle.

Any thoughts are apreciated!

 

[bones454]

It can't really be bad compression, cause sometimes it fires up good and runs nice. But then when I start it the next time it has the same problem again. Black smoke and backfires on throttle.

Any thoughts are apreciated!

black smoke is too much fuel...you sure your carb isn't the issue here, like the needle and seat sticking???

 

[ElCamino70SS]

black smoke is too much fuel...you sure your carb isn't the issue here, like the needle and seat sticking???

I can't be 100 percent sure, but it shouldn't be the carb because its like a thing that comes and goes. 1/10 starts it runs ok, but 9/10 it runs bad.

But maybe i should have I closer look at the carb 'cause its flooding sometimes.
I know its been used with a electronic fuel pump by the previous owner. When bought it i installed a mechanic pump.
That might need adjustment of the fuel levels in the carb...?

 

[bones454]

But maybe i should have I closer look at the carb 'cause its flooding sometimes.

a new piece of the puzzle we haven't heard, IMO...here's your problem :yes:

 

[ElCamino70SS]

a new piece of the puzzle we haven't heard, IMO...here's your problem :yes:

Do you think so, even though it sometimes run all right??

I will have to try to adjust them during the week and se if it helps!

 

[rkd]

Suggestions:

Use a timing light on the plug wires to help spot one that is not firing.

If it has sat for 3 years, the plug wires could have faded and all this new action has caused some failures.

The black smoke sounds like a carb issue. I would go through the steps of setting the float levels and then the idle. Same for the carb gaskets, if they sat for 3 years they could now be leaking. At least tighten the bowl screws etc. I have had several 4160 vac secondary Holleys that would leak fuel into the secondary bores from the metering plate gasket. The gasket under the metering plate that screws on the back of the main body with the 6 clutch head screws get tired and saturated with gas. The older carbs had a big void in the body. The gaskets would leak, the void fills with gas, and then it leaks its way into the secondary, dripping out the idle ports. Gives a rich, smoky idle, and stalling. Tightening the screws helps for a week or so.

Other things- the float levels, the power valve, and acc pump diaphram. I also have had the vac secondary diaphram leak, which will cause a lot of erratic running probs, but not usually a too rich condition.

 

[pnugene]

If your test tool shows a weaker spark on No. 1, go ahead and replace the distributor cap and rotor, not the whole distributor. Depending on humidity, sometimes a tiny crack in the cap will cause a weak spark and sometimes not. Let us know what you find out.

 

[ElCamino70SS]

Thanks for all your answers, I will definitely look over my carb!
Where is the best place to get holley parts?

For the moment it doesen't even want to idle. So for the right now I cant check the floater levels. But im pretty sure I have electrical problem as well. Seems like cyl 1,5 and 7 doesen't run now...!:sad:
This drives me crazy...

How can a crack in the cap affect the sparks?
Since the cap doesn't have a seal at the bottom one would think that it shouldn't make such a big difference...??
I haven't seen any cracks in the cap though, Im just curious.

 

[Elcoman]

Look down the throat of the carb and see if fuel is leaking from the boosters. I bet it is.

 

[ElCamino70SS]

Look down the throat of the carb and see if fuel is leaking from the boosters. I bet it is.

Yeah they are, immediately after i shut off the engine...
And that would be to high floater levels?
What problems could this cause?

 

[Elcoman]

Yeah they are, immediately after i shut off the engine...
And that would be to high floater levels?
What problems could this cause?

There is your problem, forget about the weak spark.

Take out your needle and seats, check them for debris. Then reinsert them and lower the float level until just a little fuel dribbles out the sight plugs.

 

[ElCamino70SS]

There is your problem, forget about the weak spark.

Take out your needle and seats, check them for debris. Then reinsert them and lower the float level until just a little fuel dribbles out the sight plugs.

Ok will try that right away!

But for the moment it doesn't even want to start and run at idle...
If i force it to start by giving it half throttle when turning the key it starts, bun runs only on 5-6 cylinders...
I need it to idle to set the floaters i guess??

 

[forcd ind]

your plugs are prob fouled now-replace them, but ck the n/s-might not be a bad idea to pull the float bowls and ck for dirt-you may want to have new gaskets on hand when you do this
at least clean the n/s, then reset so fuel just is at the bottom of the site hole-i assume you have a mech pump-you may be able to crank it over w/o the plugs and set the floats that way-if you do this, kill the ign, if the engine was flooded it can spit out fuel and ignite from a plug wire (ask how i know)
i can imagine its not easy to run to the parts store over there and get stuff like we can-good luck

 

[pnugene]

How can a crack in the cap affect the sparks?
Since the cap doesn't have a seal at the bottom one would think that it shouldn't make such a big difference...??
I haven't seen any cracks in the cap though, Im just curious.

A cracked cap allows the spark to leak to another terminal or down the cap to ground via the distributor body. Although it seems you have float problems in the carb. Good luck.

 

[ElCamino70SS]

Thanks for all the help!:beers:

I got it running on all 8 yesterday!
Lowered the floaters and replaced one spark plug!
Today I will buy 8 new and replace them all!

And I was so sure the the problem was located in the distributor......:noway:

Why does the plugs get ruined if they get drenched in fuel by a flooding carb?