edelbrock problems

[Pop's C-10]

weed eater spark plugs..Accel makes a a short plug..don't know if they really work or not.

[CSGAS]

Yeah, that's an unexpected one. The good news is that plugs are cheap to get. Even the Accel shorty plugs for headers are not so bad.

There's no telling what the lawn mower plugs may have been doing in there, running colder or hotter or if they even were sealing properly. What brand and numbers are on them?

For that matter do you know what heads are on your engine? We can determine which shorty plugs you would need, unless you are firmly set on changing back to manifolds and the downpipes that will go with them (you won't need the whole exhaust, just the downpipes)

[86shortchevy]

im ordering some hedman headers. tried the accel plugs and they were too long, i couldnt even get the plugs threaded in. i called the PO about it he said its the only thing that would fit, i guess he didnt want to look for headers that would work. Im expecting the truck to run a whole lot better once i get this squared away.. the old plugs were about half the size of normal ones.

and i dont know what heads are on it. I do know the plugs are angled though if that helps determine anything

[Pop's C-10]

Are they angled like this

[86shortchevy]

they angle towards each other in pairs. \ / \ / \ /



like this ^^^

[CSGAS]

While you have the headers completely off, or some other convenient time, try putting in the plugs you do have (you mentioned an Accel plug). Make sure they still go in and seat right before the new headers are in the way again.

The WeedEater/Lawn Mower plug SHOULD have still had 14mm x 1.25 threads but that's no guarantee nothing's odd, especially since that's not the only spec involved. IF anything is damaged, you can get a thread chaser in there while the plug holes are easy to reach.

The lawn mower plug is also at least a contributor to your cap-eating issue. It might be a good idea, depending on how many miles were put on while the roughness came back, to have another cap on hand just in case this new one was damaged; but more likely the additional cap can serve as a spare or just "in stock" for the next tune-up sometime later (insurance).

[86shortchevy]

alright guys update time:

i am re-using the old headers, the passenger side works just fine with the accel header plugs, that side is completely together and ready to go.

the drivers side had one tube that ran almost directly through the spark plug, so i cut it completely off and im taking it to a muffler shop to get it re-done. every other plug except that one has plenty of room. i screwed in all the plugs and re-installed the headers with the one tube cut out and it fit great. getting it done tomorrow.

now for something new.. every weed eater plug that i pulled out was wet with what looked like oil. is this a sign of worn rings?

[Pop's C-10]

wet with fuel or oil...tha way it was running i'm guess it was fuel..

[86shortchevy]

thats what i was thinking. ill just have to check the new plugs and see if it happens again. it doesn't ever smoke at all so im sure its fine.

[CSGAS]

The wetness still came from incomplete combustion.

Take a look at the reach/length of the correct plugs from the seating surface. Now look at the same area on the weed eater plugs. The weed eater plugs likely weren't even in the combustion chamber. The only air/fuel mixture that was getting lit up, was the little bit reaching up the thread area to the electrode.

I see where you took the tube out of your headers. I imagine it was one that ran up and over the center pair of tubes then down, and that's where it really got in the way? Should be an easy fix.

Looks like you should have a lot more progress for a lot less trouble this way. I think you'll be happy with the results of these few fixes. Of course, it will involve tuning the carb from baseline again, but you'll know you're making progress this time.

[86shortchevy]

it actually ran under the two middle tubes. where its even more in the way

[86shortchevy]

new headers are on. drove it today. ran good. it has trouble starting still if it sits for about 30-45 minutes. if i turn it off then crank it right back up its easy. i also noticed some gas around various spots on the carb. floats to high?

[CSGAS]

Very likely, also check for garbage between the needle/seat causing flooding (most common, irritating problem I've had with any carb and the "reformulated" gasolines, but that's me) and of course any loosened top screws/torn gaskets with all the times it's been apart. Sounds like great progress!

[Pop's C-10]

You can pulll tha valve cover off & get tha casting #'s off them & that'll let you know what kind they are.

[motornut]

Originally Posted by 86shortchevy

new headers are on. drove it today. ran good. it has trouble starting still if it sits for about 30-45 minutes. if i turn it off then crank it right back up its easy. i also noticed some gas around various spots on the carb. floats to high?

watch the area at the "rod" ,going threw the carb,connected to the pedal.
on stock Rochester carbs I've seen gas suddenly appear on either side of the carb,
not sure if worn (throttle plates?)would your eddy leak like that?

[86shortchevy]

i was also told a carb spacer might help. could the fuel be boiling?

[CSGAS]

I doubt you've had a chance, in TN, for the fuel to get hot enough to boil yet.

Carb spacer may help with tuning--but that's later. It won't affect the mechanical conditions (seepage/leakage)

How bad are the signs? Does it stay wet at the seam where the top meets the main body? Is it coming from anywhere else?

It's very important to know when the leaking/seeping is occurring, especially if the floats are set according to specs. Also, could you post a pic of your hose routing to the charcoal canister?

[86shortchevy]

heres all my vaccum lines.

There is gas wetness around the acc pump, choke linkage, and throttle linkage. i might just buy a new carb hah.

[Pop's C-10]

Get a rebuild kis & jus replace tha gasket...

[85_C10_Sleeper]

your best friend when tuning carbs is a vacuum gauge. Get your timing set to "factory spec" first, and then go from there.

http://www.centuryperformance.com/tu...e-spg-148.html

[CSGAS]

Don't be so sure that another carb will solve any of the remaining problems.

The pictures you posted show the vacuum lines to the carb, but I don't see the pix of the charcoal canister. On an 85/86 this should be in the pocket of the fenderwell near the core support just behind the driver's side headlight.

This canister handles the expansion of fumes and gasoline from your fuel tank. That is, when the fuel gets warm it expands a little. When there is air in the partially filled tank, the air holds fumes which expand even more than liquid gasoline when warmed.

On older trucks like mine the fuel cap was vented, allowing these fumes to just plain escape into the atmosphere when expansion occurred. Having a vent on the tank instead of in the cap would have caused problems for anyone in the cabin, since that's where our older trucks have the tank!

When I picked up my truck, someone had a cheaper, passenger car cap on it. That cap was sealed, with the expectation of a normal car having a vented tank. After running the truck for a while the sealed tank was harder to draw gas from than the ump could overcome; similarly, when at rest the expansion created so much pressure that the gas flowed through the line, past the mechanical pump (easy to do on factory-style ones) and knocked the needle off the seat to (over)fill the float area. The spring that holds the needle in place does not need much pressure to overcome it--remember stock pumps provide a max of 6 psi.

So until I found the problem and vented the cap, I had a system pressurizing itself in warm weather.

In your later truck, the charcoal canister is intended to recover the gas fumes from the air when it expands. One hose should run to the canister from the tank, for the loaded fumes. Another should run from the canister to the filler neck, to return recovered condensed fuel after filtering. A third hose should run to the carb, so any air that even might have a hint of fumes in it still, passes through the carb to get burned. I don't see the last hose running to your carb.

A vast majority of people dispose of the charcoal canister when modifying a truck. It doesn't stand up to time well, and the Ethanol content in today's gas makes things worse. What I did suspect was that the hose routing was wrong or the hoses/canister had gone bad. What I think now is that there is no canister in the truck, AND the hoses that used to go to it may be blocked or worse, plugged back into each other in a way that is sealing your tank up just like mine was.

Changing a carb won't fix that.

[oldblue1968chevy]

When I go to fill MY truck up and take the gas cap off the in cab tank it 'loosens up' and burps alot of gas smelling air out

could this cause a problem in the way it runs?

[86shortchevy]

is it the round little ball with a couple vaccuum ports on it? if so mine is completely disconnected. its back against the firewall on the DS though.

[CSGAS]

oldblue-sounds like it, but I don't know enough about your situation to know for sure...on my truck I confirmed the problem by pulling the fuel hose off the carb on a hot day, with a glass jar nearby to catch the fuel as it pushed out.

86shortchevy-the round ball is a vacuum reservoir for your power brakes and any other vacuum operated accessories (heater/vent controls, etc). The tuning standards used in the 70's 80's made a few engineers nervous about if the manifold would make enough vacuum to run the accessories by itself and still operate the brake booster safely.

Your brake booster is currently run to the port that I was originally describing for the return port--except I was wrong. Something bothered me about the long runs of hose I was describing so I did some double checking and I confused a few hoses withe their purposes in later, FI cars and trucks.

The second hose, instead of going to the filler neck, comes from a vent port on the carb bowl of the stock carb. I actually have an extra stock 85/86 Chevy truck Q-Jet on my shelf here and looked at it, and don't see the port that should be used--but it's supposed to be there. The third hose, that I thought went back to the carb, goes to an air cleaner housing fitting in 85/86; but for the same purpose, to draw the fumes from the canister.

What this means to you is, there should be no way to reroute the hoses into each other to seal the system like I thought.

If you do not see a black thing next to your core support that looks like a coffee can with 3 ports on the "lid" then someone's done away with your canister. The two hoses connected to the carb and air cleaner can be removed without affecting the operation of the vehicle (only the ability to pass smog checks is hurt, because the float bowl is venting to plain air again).

The first hose, I'm now going to bet, was plugged to stop fuel from dripping out. Look for a hose, coming from the gas tank to the engine compartment, that someone jury-rigged shut. Maybe a bolt inserted in the end, a clamp over-tightened down, something. It could even have been cut shorter to "clean" things up, so look by the firewall below that vacuum reservoir or even by the frame rail on the driver's side. I doubt anyone capped it off at the tank because that involves reaching under the bed.

IF you find this, the easy way to find out if my theory (it's still a theory for now) is correct, is to wait for a day when it will warm up, and pull whatever's plugging the hose when you find it. If I'm right, fuel will drip out again, and you'll find a way to vent the hose as a solution.

If you do find a charcoal canister properly hooked up to the tank, then you at least have not spent any money and moving on to the next possibility won't be so frustrating.