650 dbl pmpr HELP!!!!!!!
 

My car was cutting out under hard ecelleration. A friend suggested I reset the bowl floats before doing anything. So I re-set the floats. The front one was very close. The back one took a lot of adjustment.

Procedure:

Engine running, remove site plug and adjust fuel level until mild bump sideways spilled a little fuel.

I took the car out for a drive and made it about 3 blocks. It was like someone reach over and shut the ignitian off. I poped the hood and could here fuel running like a faucet (pump still on). I shut the pump off and pushed it the 3 blocks home ( you think ya get a lot of attention driving a cobra? Try Pushing one!) I pulled the carb the next day and completely went thru it. New bowl seats, gaskets, etc.

While doing this a friend loaned me his 750 vacuum. Ran OK but was not fat enough for my car.

I put my shiny newly rebuilt 650 on today set the bowls and all seemed to be great. Decided to drive it to work at lunch and ran great! Went to drive it home and made it about 3 blocks, going from second to 3rd I thought the throttle stuck wide open. Hit the kill switch and coasted into the nearest lot. the throttle was not stuck? so I turned the fuel pump back on. AGAIN, I could hear fule running into the motor! This time I got a friend to pull it the 2 miles home. (Not quit as eye catching as pushing it)

What the F@#$ am I doing wrong?

Stock Holley 650 dbl pumper
Holley Red fuel pump 6lbs of preasure at the carb

Ray

fuel...
 

aside from the sticking throttle situation... (Not Good)...

do you have a fuel pressure regulator in the system somewhere?

did you "replace" the needles when you went through the carb(s)?

Also... I'm wondering if the needles (rubber tips) are slightly compressed or have become hardened now (sometimes not visual to the naked eye) and if you are blowing the needles off of the seat right at 6lbs. I take the needles "out" of the bowls, blow them out with compressed air to be sure there is not some mild buildup or junk stuck in them. I had this problem once on a previous car from a crappy, generic/silver Kragen type inline replacement fuel filters where the glue from the NEW filter became dislodged and got stuck in my needles a few times til I figured out where it was coming from. Never used those generic type filters again after that. Good Luck.

vetklr,
Do you have the 2 bronze filters removed from the fuel inlets?
Bud

The needles are new, I just replaced them. The carb does not have the bronze filters in the inlets; however, I do have a filter before the pump and one in the fuel log.

I was extremely carefull when I took it apart and cleaned it. Insuring there was no debre in the carb. Everything not replaced was soaked in carb cleaner and blown out with air. I checked both filters and they did not have debre in them?

The only thing that was peculiar to me was; since there is no dry float setting for a 650, I decided to eyball the float setting. I thought I set it well below where it should have been to run out the view hole. when I attemted to set the level once on the car, the primary (front bowl) ran over almost imediately. This resulted in fuel shootng out of the view port until I got it shut down and adjusted properly.

I think I still have a float sticking? I just don't understand how it could still be doing it after I have cleaned the entire carb and replaced the bowl seats.

I will pull it all apart again tomorrow and see what I can find.

The only thing aside from faulty needles and seats is too much pressure. take off the fuel line put a pressure gauge on the line (not in line) on the line itself. turn on the pump.

If you have more than 5.5-6 psi you need a pressure regulator.

next time...
 

The next time it cuts out on you, pull the sight screw immediately and see if fuel comes of either side. If so, you are getting fuel! Again, if you don't have a regulator, this could also be your problem.

Check your floats too. If they are brass be certain they do not have a leak allowing fuel to get inside or have collapsed or been dented. If you have the black hard foam type check to be sure they have not begun to absorb fuel, once they do, they become heavier and will not function properly to control the motion of the needle and seat, and any adjustment setting you make will continue to change as the floats get heavier.

Rick

Ray,

This won't help with your problem but to keep from taking the sight plugs out and having fuel splash out, I replaced mine on all the cars with the see through ones and like them very well. I can adjust the float levels without taking the plug out and it is much easier and faster for me. I have had them on two Holly 850 double pumpers for years and they work great for me.

Ron **)

Make sure the top of your air cleaner is not coming in contact with, and closing off, the two venturi tubes that stick out of the middle of the carb.

If it does, your carb will flood out and gas will go everywhere (just like you described).

Most new carbs have the tips of these tubes cut at an angle so so this won't happen. Older ones don't.

Traveler,

Thanks, I will check the clearance. I don't think there should be a problem, but it wont hurt to check.

I turned on the pump this morning and watched. I could see fuel dripping out of the to front venturies. I shut the pump off and pulled the sight plug and fuel came pouring out. I pulled the float seat, did not see anything wrong but cleaned it anyway. I reset the bowl level and did the back bowl just to be sure. If any thing the back looked a little low. I also check the movement of the float thru the site hole. It appeared to move freely.

I checked the preasure, it stays right at 5lbs.

I will give er a shot again and see what happens. This time I think I will take my wife with me. That way if it quits again, I can make her push while I sit and make vroom noises.

You either have a crack in the metering block, a warped metering block or body or you need a new set of needles and seats.