From idle to WOT and the car dies

[Harlow]

Alright, me and my dad had the car out at a deserted business park yesterday. We made one full throttle pass with the carb as it was. then we decided we would try going one stage leaner, when I would punch it from a dead stop and car would just die, no blowback, backfiring or anything. We then changed it one stage richer and we had the same problem. After that we changed it back to the stock rods and I still had the same problem. All throughout this time the car had been real hard to start, as if it may have been flooded. What should I check? I was going to check the rods and make sure they were the correct ones and seated properly, but what else should I check? Heres whats got me worried. Two days ago we took the rods out to confirm which ones were in the carb, but we got distracted and didn't fasten down the last rod/spring. Yesterday morning I took the car out for a ten mile cruise and had forgotten about the rod/spring, later that afternoon we went to go take it out for this testing run and found that the rod was hanging over the edge of the carb and the spring was gone. We looked around and could not find the spring, if that spring had gotten sucked up could it cause major damage?


- Scott

[Plumcrazy]

Check to make sure the accelerator pump is working.

[Harlow]

The accelerator pump is working. when I pump the throttle it shoots fuel out the nozzles.

- Scott

[Harlow]

Anything else I should check? I pulled the rods and checked those and everything seemed fine.

- Scott

[Ghoste]

Float level?  Fuel pressure?

[Chryco Psycho]

The squirter may be too small but eddy only has small medium & large to choose from if ti is an eDDY carb

[jg68]

Alright, me and my dad had the car out at a deserted business park yesterday. We made one full throttle pass with the carb as it was. then we decided we would try going one stage leaner, when I would punch it from a dead stop and car would just die, no blowback, backfiring or anything. We then changed it one stage richer and we had the same problem. After that we changed it back to the stock rods and I still had the same problem. All throughout this time the car had been real hard to start, as if it may have been flooded. What should I check? I was going to check the rods and make sure they were the correct ones and seated properly, but what else should I check? Heres whats got me worried. Two days ago we took the rods out to confirm which ones were in the carb, but we got distracted and didn't fasten down the last rod/spring. Yesterday morning I took the car out for a ten mile cruise and had forgotten about the rod/spring, later that afternoon we went to go take it out for this testing run and found that the rod was hanging over the edge of the carb and the spring was gone. We looked around and could not find the spring, if that spring had gotten sucked up could it cause major damage?


- Scott

Its not going to run right without that spring, hopefully it didn't go down the intake, i'll assume it had this problem before you lost the spring, those 750 eddys had a serious issue in the primary metering, there was big talk about it awhile back, edelbrock decided to build the 750 with primary 600 metering , i had one that was a total piece of junk, if you nailed it from a dead stop, it would stall, if you feathered it, it would be ok after the stumble, i did my own mods on it with some pin drills, opened up the IFRs .003 & opened the squirter from the .035 to a .043 & extended the pump shot (bending the arm with it in top hole), this helped alot also, the primary boosters on the 750s are useless, i sold all that junk & put a holley on, of coarse now i'm running a 750 speed demon DPer.

Just 2 weeks ago i purchaced a couple of 600 eddys for a TR set-up, just for kicks, i put on one of the carbs, i'll be damned if it didn't have excellent throttle responce & flat out boogys for a little carb, its too small for this 440, but it doesn't have dead spots, bogging, nothin, just goes, so that tells me those 750 eddys have problems, good luck

[Ghoste]

I had a 750 Eddy on my car and it was fine.  The wierd part is that when I switched to a 750 Holley, I went through exactly what you described until modifying it.  Go figure.

[Harlow]

alright guys, heres the weird part. The car ran AWESOME until I made the first metering adjustment and no matter what changes I made (even back to stock) I couldn't get rid of this problem. I had an extra spring, so it does have a spring in there. Either by messing with the metering rods it screwed something up, or something else went wrong and it just so happened to be while I was changes the rods. I'm going to start it up today and see if the problem is still there. I've got a hard time believing that its just a tuning error because like I said, it ran great before I messed with the rods.


- Scott

[Big Lebowski]

Ok, this happened to me before. Before I put the 6-pack on my 6pack car, I broke the motor in with a new 800 Edelbrock, anyway I had the same problem...The fix was Mr. Fuel pump wasn't sending enough gas up to refill the floats.

[Harlow]

Lebowski, my dad was thinking the same thing. I guess I'll check the fuel pressure and see what I get.

[Harlow]

I checked the fuel pressure this morning, it was 5.5 psi while cranking. I'm not sure what it should be, my dad thought between 5 and 7 is ok. After idling for a while the car seemed fine so we took it back out. It ran fine, we did about an hour of tests (turning the car off an on around 5 times), towards the end of the testing the car did the same exact thing. I gunned it the rpms started to go up (about a second) and then stops instantly (no sputtering or backfiring just stops on a dime). I started the car back up (very had to start) and we changed the timing back to where it was before and tried it again to see if the problem was fixed. It did the same exact thing, only this time the battery was already so dead it didn't have enough cranking amps to start the car. Could this be an alternator problem? where the battery isn't getting charged so the spark from the coil gets too weak? Does that make sense that on hard acceleration that the spark would be too weak, but on slow cruising acceleration it does alright?



- Scott

[firefighter3931]

It sure sounds like a fuel delivery problem. One thing to check is the fuel pump pushrod because they do wear out over time. The correct length is 3.25 in. There is a pipe plug under the fuel pump where the rod inserts into the block....you have to remove the pump and then the plug and it (pump rod) will drop right out. I would check this out and eliminate it as a potential cause of the fuel starvation. 


First thing i would do is set up a fuel pressure guage that could be seen while the car is moving to see how the fuel pressure is being maintained under hard acceleration....then diagnose from there....assuming it is dropping. 



Ron

[Harlow]

Well I took the alternator and had it tested. It was toast, that would explain why the battery would keep dying. Tommorow I will take the car out again and see what happens. I'm thinking that it is not a fuel problem just because there is no sputtering or anything, and the problem only occurs after driving the car for a while  and turning it one and off quite often. I'll report back and let you guys know how it goes. 

[Big Lebowski]

  I worked at a Mopar resto shop for 5 years, and it's always nice to have a new carb. to bolt on. That way you can see if it does the same thing. I still think it's your fuel pump because when I had the same problem...you could drive it all day long, but when you hammered it with wide open throttles, it just emptied the bowls. A new fuel pump solved my problem. I also like elec. fuel pumps, just make sure it's regulated...I've seen high pressured pumps just blow the Holley seals, and pump the gas all over the engine. Not good.