4reboy

Hey everyone, long time no post. The other day I began experiencing a big problem with my car. After getting off the freeway and coming to a stop my car began to sound weird and shake at idle. Also while cruising after that it seemed as if my car was inconsistently accelerating, like on and off very rapidly. I checked it all out today and here is what I found:

Cylinders 1, 3, 6, and 7 are not firing. I pulled the plugs while it was running and the engine would not stutter or anything. However, there IS spark as seen by the arc from the cap to the plug wire when held close. I therefore thought it was a fuel delivery problem so I changed the pump to carb filter, but that didn't help at all. Then I realized that the cylinders that are not firing is EVERY OTHER cylinder in the firing order.

1-3-7-2-6-5-4-8

I also pulled the plug for cylinder 1, thinking maybe it was bad, but it looked perfectly healthy.

My engine is a fairly stock 351w with a 650cfm edelbrock carb and pertronix ignition module.

What can the problem be? I'm now thinking that my pertronix module is bad, but I'm not sure if that makes sense because I'm still getting spark coming out of the cap on all cylinders. However, it could still be messed up and sparking at the wrong timing.

Any suggestions?

frdnut

Are you running a dual plane intake?..If so are all of those cylinders together in one plane?..If so you must be having a carb problem on that side.

4reboy

I have an edelbrock performer intake, and I believe it's dual plane? based on this picture it looks like the left side of the carb would be leading to cylinders 1, 4, 6, and 7, where my problems are.



So is it just clogged or something? I've never taken apart the carb before, just removed it on and off many times. What all is involved, what needs to be cleaned, and with what products? Also, would I need a new upper gasket since I will have to take apart the top portion of the carb?

I hope that's all the problem is, I should be able to handle it, just need some instructions

Starfury

I agree, it does sound like a carb issue. Sounds like the left side is having fuel delivery problems. I'd take it off, pull it apart, clean it, and put it back together. But before you tear anything apart, try to verify the problem is fuel delivery. If you can, open up the valve on a propane torch into that side of the carb and see if the engine smooths out. If you don't have a torch, try a little starter fluid spray. If the misfires go away, it's a fuel issue and you need to clean out the carb.

If you really need an Edelbrock top gasket, I've got a couple in my garage. I bought a 5-pack a while ago and have a couple left. You might be better off picking up a rebuild kit, though. I believe we have one on the shelf at work.

Disassembly is cake, just don't lose any of the parts. The only special tools you'll need are a couple torx bits. If you get lost, give me a call and I'll run you through it.

Get yourself a can of spray carb cleaner along with a container of carb dip. After disassembling everything, let the carb and individual metal parts soak in the carb dip overnight. Pull them out and spray the small passages with the carb cleaner, then let everything dry. Reassemble with new gaskets and parts and you'll be set to go.

4reboy

Thanks for the tips Tad. I just pulled the carb apart and put it back together but the problem is still there. However, I think I may have taken a cheap way out and that could be why it is still clogged.

I just removed the air horn and took all the venturi's out, cleaned it all with carb cleaner real good, and reassembled. I never took the lower half on the carb off of my intake. I think that could have been my mistake as it didn't occur to me that the clog could be in the bottom part of the carb. I may pick up that rebuild kit if you think the clog could be in the other part of the carb. If that's the case I will take the whole thing off and use the carb dip stuff.

I'm almost positive it is a carb issue, I have spark coming out of the cap into the plug wires, and I doubt all four plugs or plug wires went bad at once. It is either my pertonix ignition module (but I doubt that since if that went out it probably wouldn't run at all) or the left side of my carb is clogged.

Starfury

Guarantee it's something having to do with the left side of the carb/intake. You won't get all of those cylinders dying with an ignition issue.

If the carb's clogged somewhere, it's most likely in the bottom half. That's where all the important passageways are. I think a rebuild is in order. You also need to think about replacing the fuel filter, and checking for rust in the gas tank.

4reboy

I'll pick up a rebuild kit then, but can't get over there until tonight when I can find a car to borrow lol. Does your store have edelbrock kits in stock? I have the thunder series 650cfm.

Replacing the pump to carb filter was the first thing I did, but I should also replace the tank to pump filter (the larger canister type). My tank should be OK, but it's always something to check. It looked new a few year ago when before I put it in, and the car hasn't had long sitting periods.

4reboy

Do I need a full rebuild kit or just the gasket kit? huge price difference... My carb is only 4 years old or less with not too many miles, if just the gasket kit is fine that would help my wallet out a lot

Starfury

I'd imagine just a gasket kit, if you can get away with it. There really aren't that many. The top gasket and then the booster gaskets are the only ones I can think of. I think the rebuild kit comes with needles, accelerator pump rebuild, and a couple replacement small parts. I know we've got a rebuild kit on the shelf, but not sure about a gasket kit.

Pick up a carb base gasket while you're at it. We've got some decent ones, but they're hidden in the back. I know where they are, but some of the other people there may not. The stock replacement gaskets are paper thin and don't work well. I prefer the thicker Mr Gasket ones for better sealing.

If your tank is only a couple years old, it's probably fine. I'd still change the filters, though. You'd be suprised what gets mixed up from the bottom of the tanks at gas stations when they refill from the tanker.

001mustang

I went thru my 1405 after about 6 years; lot of sitting time.

Was able to clean up the metal parts, the needle valve, pump, etc.

There are some small gaskets which I was able to reuse.

You could take carb apart first to see what you need on reassembly.

Problem I found was scaled up small passages. Was very careful to clean every carb oriface.

Been driving car more since 2007(i think) carb rebuild and it works perfect.

Most likely you will only need a few gaskets and can reuse other`gaskets.

Ended up buying individual jets because the jets in the jet/rod kit too small for my tuning needs.