HELP! Trouble with Edelbrock carb..car running rough all of a sudden..

Ok..I need help...brand new motor..350..brand new everything...first time it fired up (posted youtube of it a few weeks back) started and ran *****in...only put a few miles on it taking it to the exhaust shop etc..The electric choke wasnt hooked up yet.....parked the car, installed Glenns Rebel Wire wiring harness, hooked up electric choke, lights etc. Fired up the same but seemed to be running rich(black smoke now out the exhaust) ..now ever since, car sometimes has a hard time starting, sometimes starts right up...but the longer it idles, starts running rough, idles high and eventually dies........HELP....it has a new Edelbrock Performer Carb....does it have something to do with the electric choke?? Or was it just a coincidence it started having problems after that? I know it can probably be a number of things, but it is timed right..and like I said before, ran great.(check my thread with video).. give me some things to check please! Any suggestions would be great...thanks guys......

 

check the float valve for dirt....

 

I was going to say, kinda sounds like a float problem, or flooding?

 

Thanks guys...have not checked that yet...

 

Check the fuel pressure, I had a pump go bad and give the same symptoms. put a gauge on it and it idled at 15 psi. I don't know if the pump was made for that high pressure or something went wrong, but it didn't make the carb happy.
Anyway changed the pump and everything is fine.

Frank

 

I was thinking that too...Im running a Edelbrock fuel pump says its output pressure is 6-7 psi and needs no regulator in most cases.. Ive been told that should be ok...but Im tempted to run a stock fuel pump...is 6-7 psi too much?

 

Just in case you might want to try taking the choke cover off and wire it open .

 

6-7 psi should be perfect. How is your gas tank? It is possible it could be picking up rust or dirt from the bottom of the tank. I like the clear gl*** inline fuel filters. Makes it easier to see whats flowing through.

 

or pull the wire off of it... see if disconnecting the choke makes the problem go away...

 

I'll bet it's fuel pressure too. My Elky ran way too rich no matter what I did until I put a regulator on it. Stock GM pump was putting out over 13 psi (that's as high as my gauge would show) when I dialed it down to about 6 lbs. It ran perfect and started as good as a fuel injected car. Love those Edlebrock carbs!

 

sounds like the choke is the issue, i never run a choke and never had any problems in my life. just takes a little bit to warm up to get it to idle but it has never bothered me.

 

Lean your choke up a tad and your problem will go away.

 

Tank is brand new too...we even checked that too to make sure there wasnt blocked...

 

interesting....like I posted...seemed like it was fine before the choke was connected...would that cause the symptoms it was having? Dont understand why having it connected would have such a problem,,,thanks guys...gives me a few things to check tomorrow...anybody else?

 

Make sure you have true "12 Volts " going to the choke with a good ground, if it keeps up lean it out or open it all the way for a test...............

 

I had a problem with a new Edelbrock carb flooding and running rich. A friend said it was the float and we were on the road going to an event, so we pulled it apart. The 2 float halfs were not soldered all the way around and the float was sinking. Edelbrock replaced the carb when I got back from holidays with the car. I was on holidays at the time though so had to pull the carb apart every 3 days and get the gas out of the float, use some sealer that was partly gas resistant for a few days and go. Was a pain, but made it home with it. Pat.

 

This problem is 100% the pump being stuck, take the top off and clean it up and you'll be fine

Matt

 

Thanks guys.....is this something that would happen out of the blue? Running good one day..the next, not so good?

 

Anybody else have some ideas?

 

Who installed the carb? was it Mark? .Remember we tried the adjusting screws all the way in and the car would not turn off.

 

Sure sounds like choke to me. Longer it runs the worst it gets. Sounds like it's not opening up. Make sure you have power and a good ground. The choke is adjustable, maybe it's set to rich.
Jeff

 

Thats funny...but I installed the carb..so Mark is off the hook on this one!

 

I think youre right..which way doess it get turned to lean it? I think it is set at the first mark right now(one closes to the top of the choke) My dad has his set in the same place on his 59 El Camino and no problems..

 

I don't remember for sure. I just turn it and watch the choke, it'll open and close the choke. Take some spring pressure off and you are going the right way. Is there a vacuume choke pulloff on that carb. That could do it too. I think the pulloff may be inside the choke housing. If it is there should be a washer gasket or o-ring that seals the vacuume port. It may not be there or the housing may be loose. I'm guessing about how the pulloff is designed...
Jeff

 

FWIW, if you don't fix the problem, check for dirt anyways. I've had my beater truck, which is a TBI-equipped Chevy, for about 4 years. In the first two I put all new fuel lines on it, filter, and changed out the gas tank. Last weekend it was running rough if I tried to give it any power, like to go up hills or to p*** cars.

Well, I found three good sized chunks of leaf in the back side of the fuel filter that I just have no explanation for how they could even get there. On a TBI the pump is in the tank and has a nylon sock over the pickup. Nothing's been apart lately for them to get inside, and it's run fine for many thousands of miles before this. And it was just a guess on my part that I should try changing the fuel pump (which is always fun to do in the parking lot of Advanced Auto).

On a new build I'd guess it's going to be like most everyone posted, you need to tweak some adjustments here or there, but I figured I'd point out sometimes you never know what's going to turn up.

 

Thanks rustynewyorker...hey Im up to try anything right now..

 

Bent metering rod.

 

As stated it sounds like trash in the needle / seat. It could be high fuel pressure, do you know what you have? Choke could be hanging up, or a bent metering rod (like C9 says) or the piston it rides on may be sticking.

It's a long shot but it could be the secondary boosters leaking from the gasket between them and the carb main body. If they are there will be gas puddled in the cutout in the main body around the boosters. A couple washers under the heads of those screws usually fixes this (or so I'm told).

You have to pull the lid off the cab to get to those screws so it would be a good idea to check for trash in the needle and seats and float height / drop, as well as the adjustment between the choke air door and the pulloff piston in the choke spring housing.

The manual for these can be downloaded here. FWIW it recommends a maximum of 6 Psi W/ 5 1/2 preferred fuel pressure.

Hope that helps.

FWIW choke problems in the past are why I have the manual choke 600 Edelbrock on my A, if nothing else, when the knob is in, I KNOW the choke is off.

 

Thanks for all the info.....would this be something that would happen all of a sudden on a new carb with less than 1 hour running time on it? What gets me... is that it was running fine prior to hooking up electric choke.....thanks again

 

I have the one on my A now. I am going out to my A Thursday. It is running rich to the point of the pipes being sooty (haven't dialed on the carb yet beyond initial idle speed and mix adjustment) . As the car is not where I am I asked around and did research (as you're doing now). One of my clubmates in Ininers International actually wrote an article for our newsletter (12 Port News) that describes the secondary booster thing. I am going to check mine as I suspect it is at least seeping. I figure it probably doesn't leak at first, not till after the first heat cycle or two.

Like I said, in your case, it's a long shot, but something that's easy to check.