2x4 carb problem

ssnake · #1 (**permalink**) 05-07-2003, 09:50 PM

For those of you who are running a 2x4 setup on your 427 S/O with twin 660 holleys..Has anyone
had any problems with #1 Carb, carb backfire, won't start or won't idle?
I took my car in for an oil change and when I tried to start it, I apparently flooded it (blunder #1)and it wouldn't start..It backfired through #1 carb..A backfire so loud and sharp I couldn't believe..When I finally got it to start, it wouldn't idle and would die. It would run at 2k rpm and beyond.
I coaxed it home and parked it..Pulled the power valve and it seems okay..Haven't replaced it yet
I'm going to pull the plugs and see if there is any fouling. Everything was working fine prior to the oil change.
I'm reluctant to try to start this unless I go through the litany of options.
Any thoughts or direction would be appreciated.
Thanks,

Don

Trans-Am Jim · #2 (**permalink**) 05-08-2003, 07:18 AM

Unless you have the blowout valve (either aftermaket or OE if newer Holley) installed in the power valve circuit, the power valve is probably toast and would cause an over-rich idle. You said you checked the valve and it "seems OK" Unless you have a power valve tester, there is really no good way to be sure. Get new ones (both carbs) and start from there.

427 S/O · #3 (**permalink**) 05-08-2003, 07:40 AM

And get this power valve protector kit
from Holley (PN - 125-500).

ssnake · #4 (**permalink**) 05-08-2003, 09:31 PM

Thanks for the direction, 427 S/O and Trans-am Jim..
This should be a fairly simple process to replace both power valves. The quest begins to find the power valve protector kit. Great recommendation.. There should be someplace here in Dallas that has it. It's been a long time since this ole gearhead has touched a motor..
With the holiday this weekend, I may not be able to get to the car..I'll give you guys an update how this progresses.
Thanks again.
Don

Trans-Am Jim · #5 (**permalink**) 05-09-2003, 07:19 AM

This is not the Holley, but same idea. I put 'em in my 1849s and they work just fine. Simple installation, about 5 min. per carb.

http://www.jegs.com/cgi-bin/ncommerc...24&prmenbr=361

Pete C · #6 (**permalink**) 05-09-2003, 08:03 AM

Don, Have you checked the timing? It is possible that the distributor was moved during the oil change. Also, check the rotor. If you have an MSD with the round rotor, the contact can slide in the slot on the rotor and the result is backfire and poor idle as you arc to plug wires. This has happened to me and my car had the symptoms that you describe.

Cheers, Pete C

ssnake · #7 (**permalink**) 05-09-2003, 08:54 PM

Pete C..I have an MSD..I'll check the rotor and timing..This is the kind of thing I could have overlooked when trying to find a simple solution to the problem. I'm going to try to tackle this tomorrow night. Will let you know..
Thanks for the input.
Don

ssnake · #8 (**permalink**) 05-09-2003, 09:04 PM

Trans-AM Jim,

I called my local carb shop and they said
"Power valve protector"???
I'm in trouble..
I can see I'm going to have to check around for
this. Do you think it would work on a model 4160 Holley?
The quest begins tomorrow..
Thanks for the info.
Don

James Baldwin · #9 (**permalink**) 05-09-2003, 10:21 PM

Try this link

http://store.summitracing.com/partde...art=SPE%2D2408

ssnake · #10 (**permalink**) 05-10-2003, 07:28 PM

James..I was able to locate the power valve protector @ Speedtek Performance on Buckner Blvd.
Will get over there Monday..
Appreciate the link.
BTW..It was a nice ERA you had..I'll try to catch up with you sometime.
Thanks,
Don.

ssnake · #11 (**permalink**) 05-12-2003, 08:48 PM

Guys..Here's the results of everything.

1. In checking with a couple of dealers they informed me that the 2X4, model 4224, 660 CFM Holley does not have a power valve. I pulled the wrong thing off the carb. Re-installed it (Crap!)

2. Checked the floats on each carb..everythings ok..

3. Checked the MSD cap..No problem there..

Started the car up after parking it over a week ago. It did a little pop through the first carb. Nothing like the previous time. Once it got to operating temp, I backed off the carb idle and it idled fine. Re-installed both air cleaners. Shut the car off and it started fine.

Understand that I really didn't do anything to the carb or anything for that matter..With this in mind, it warranted a 45 minute test drive..Of course, it had to be checked throughout it's rev range. Not a single problem was encountered.

The only thing I can speculate is a stuck float or something of a temporary nature that caused this condition.
The weight of the 800lb gorilla is now off my back.
Maybe it didn't like its oil change.

I don't expect any further developments and will practice judicious use of the pedal when starting this great machine.

Don