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tgx 08-05-2009 10:40 PM

Chevy 283 intermittently runs well
 
Hi guys.

I've got a 283 SBC with 305 cylinder heads and mild cam, Edelbrock Torker II and an Edlebrock Performer Carb. I've been working on this setup for a few weeks now and over the weekend it ran for the first time like an absolute champ. I let it get totally warm before I embarked on the road trip. Today...after making NO changes, and not having been started it since Sunday, it's back to its old shenanigans. I did not allow it to warm up fully before embarking and it died at every stop light...shoot it would die going down the road if you let off the throttle and it is hard to start.

Other items, it is running an electric fuel pump with an inline pressure regulator set on 5, whatever that means, it has settings 1-5. 4,5 are recommended for 'v8's'.

The carb is not an electric choke model, but a manual one. Normally if I keep it slightly choked it will stay running under low throttle but lose power when on the open road, so I unchoke it. But this becomes a serious nuisance with the constant choking and unchoking.

Would an electric choke help?

DoubleVision 08-06-2009 02:11 AM

A electric choke won`t help matters much. The choke is telling you that you have a problem elsewhere. If it runs good with the choke partially closed it means it`s allowing less airflow and more fuel in, indicating the mixture is too lean with the choke in the full open position. Check it for vacuum leaks, check the carb and make sure it`s not plugged up and check the spark timing, also check fuel delivery. It`s also likely been mentioned the Torker II is the wrong intake for a street bound 283. A dual plane intake like the performer would be far better. You may want to check the intake bolts for tightness as well. What ignition system are you using?

tgx 08-06-2009 10:16 AM

Quote:

Originally Posted by DoubleVision
A electric choke won`t help matters much. The choke is telling you that you have a problem elsewhere. If it runs good with the choke partially closed it means it`s allowing less airflow and more fuel in, indicating the mixture is too lean with the choke in the full open position. Check it for vacuum leaks, check the carb and make sure it`s not plugged up and check the spark timing, also check fuel delivery. It`s also likely been mentioned the Torker II is the wrong intake for a street bound 283. A dual plane intake like the performer would be far better. You may want to check the intake bolts for tightness as well. What ignition system are you using?

Unfortunately I did not assemble the engine, I bought it as is so I didn't have much choice on what manifold came with it. The engine only has 1,000 miles on it after it was rebuilt. I've had the pan off and the cylinder bores seem to confirm the low miles. It came out of a 'deuce coupe'. The guy installed a fuel injected 350 and thus replaced this carb'd 283.

It's a standard dizzy, points type with vacuum advance. I am wondering if the fuel pump is weak. I have a glass Russell see through filter under the hood and I notice that sometimes the filter is nearly empty. I've been told that is kinda meaningless, but thought I would not it here anyway since I've heard that Edelbrock carbs like to flow a lot of fuel. I'll run a smoke test and see if I can find a vaccuum leak, but would that cause and intermittent issue like this? The car has a new fuel tank and fuel line and the carb looks to be new as well.

I was going to replace the fuel pump next but I wanted to get some indication from someone more knowledgeable than myself that this might be a fuel delivery issue. before I forked over the money for one of those Holley electric pumps.

DoubleVision 08-06-2009 10:26 AM

It does sound like it`s running out of fuel. If you don`t have a fuel pressure gauge it would be a wise investment to get one. Eddy carbs like about 5 psi fuel pressure. Being your running points that could also be the issue as many carb problems dianose the same as ignition problems. The best place for points is the trash. I would go with a HEI or get a conversion kit for the points distributor. If your running a mechanical fuel pump I would just use a stock replacement pump, make sure you pack the spring cavity with lube before installing it.

tgx 08-06-2009 10:38 AM

Yes I prefer the HEI distributors as well.
As this dizzy is new I think I'll start with the fuel
pressure since that sounds like it isn't necessarily a bad
thing to look at. I'll have a look at the points also.

I'm not all that knowledgeable about dizzy curves, cam timing
and dwell so I don't like to tinker with it. I usually just end up
worse off for my efforts. As the engine was apparently running fine
when removed from the car, the only difference would be the fueling
system. The current fuel pump sat idle for a number of years so it's possible the pump isn't all it could be.

Thanks for the tips!

lg1969 08-06-2009 12:47 PM

I would check the fuel pressure regulator. It could give you problem. The electric fuel pump could be intermittent.

tgx 08-06-2009 02:02 PM

Quote:

Originally Posted by lg1969
I would check the fuel pressure regulator. It could give you problem. The electric fuel pump could be intermittent.

Well I added the pressure regulator after seeing the fuel filter empty intermittently so I figured if I added the regulator it would create a steady stream of fuel. That hasn't happened so it must be not receiving a steady amount.

I have replaced the fuel pump with a second electric one I had sitting around. Both of the pumps I have tried however are probably at least 8-10 years old now and are just these el cheapo jobs.

It may be that these simply can't flow enough fuel to keep up.

I think I will also check for a voltage drop and see if the circuit the pump is wired into isn't causing some sort of drop in flow rate.

lg1969 08-06-2009 02:22 PM

If you have a serious voltage drop, most likely the gauge wire is not heavy enough to handle the current. Remember the lower the gauge wire the thicker wire.

moontanker 08-08-2009 11:31 AM

283
 
Pull all the plugs and replace them.This has happened to me and I dropped a ton of money,If it has set up the plugs are fouling maybe like mine.So simple it floored me when I saw it finally.

tgx 08-09-2009 01:19 PM

Quote:

Originally Posted by moontanker
Pull all the plugs and replace them.This has happened to me and I dropped a ton of money,If it has set up the plugs are fouling maybe like mine.So simple it floored me when I saw it finally.

Well I replaced the fuel pump, check the points gap. Thus far it is still acting the same. I also richened the mixture...and while it produced nice eye burning exhaust, didn't help the stumble and die issue. So set the carb back to previous settings. Next am checking for vaccum leaks. I'll swap the plugs....again...as I do hear a miss or two. Is there anyway to 'unfoul' plugs? These things aren't getting any cheaper these days.

Going to a car show in an hour or so.

lg1969 08-09-2009 04:37 PM

I'm not to sure about stumble and die. Does it stumble the instant you are applying the gas pedal or just cruising at a steady speed? I would check the float Level in the carb. It may be set to high or check if the float valve if it's closing properly.

tgx 08-10-2009 09:24 AM

Quote:

Originally Posted by lg1969
I'm not to sure about stumble and die. Does it stumble the instant you are applying the gas pedal or just cruising at a steady speed? I would check the float Level in the carb. It may be set to high or check if the float valve if it's closing properly.

Yes. I am under suspicion about the carb now. As for the stumbling, here is an example. The entrance to my driveway has a street drain that runs across it so it is sort of dished. When the car is acting up, if I go over this dip...at any speed... the car begins to stumble and it is very difficult to keep running. Also if I pull to a stop sign and leave it in gear (automatic), and I don't add choke to it, put it in neutral or some other corrective manipulation of the throttle, it will die. Going downhill at a moderate incline it will begin stumbling and could potentially die, again applying choke saves it (or modulating the gas pedal). It just ends up being a lot of work to keep the thing idling without a stall. On the open road at speed though I'm not seeing any problems. I should mention a week ago I went for a drive and the car was absolutely flawless and exhibited none of these problems. I parked it and started driving it again 2 days later and it was back to its shenanigans.

tgx 08-10-2009 10:03 PM

2 Attachment(s)
Hey guys,

Wanted to give an update. I think I may have found the culprit.
Removed the top on the Edelbrock tonight and found a nasty little surpise inside. Looks to me like rehydrated varnish, probably from fuel left in the float bowl when the previous owner removed and parked the motor. My tank is new as are the fuel lines and I have two filters in place. The goo is the consitency of wet mud. I removed all of the gas in the bowls and swabbed it out with some towells, then dressed it all with GumOut carb cleaner. My fear is that some of this muck has made it further into the carb and is probably causing the intermittent fuel delivery. With any luck it will clear itself out again. Otherwise I'll have to pull the carb off altogether and get it hot tanked or something. Anyway, take a look at the pics. The red circles on the one show where heavy deposits were on the one bowl. The other bowl was the same, but less in the power valve area since it actually has a power valve on that side. The gas in the bowls looked like the consistency of fresh squeezed brown lemonade.

cobalt327 08-11-2009 03:45 AM

Quote:

Originally Posted by tgx
The gas in the bowls looked like the consistency of fresh squeezed brown lemonade.

Prolly rust from the previous fuel system, but whatever it is, it needs to go.

All that you may actually need to do is disassemble the carb and spray-cleaner all the orifices and air bleeds real well (compressed air would be nice) and reassemble w/good gaskets.

Good luck.

lg1969 08-11-2009 09:34 AM

It most have been left over from the woodstock error :cool:
Yeah, That would make the 283 run like crap.


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