Edelbrock dumping copious amounts of fuel

impulsive-RX7 · 06-14-2008, 06:37 PM

Edelbrock Performer 600cfm #1405

What would cause this carb to dump massive amounts of fuel into the engine; with no throttle input and even after the car is shut off? I mean it was literally pouring fuel into the primaries. Massive flooding.

Was previously running just fine. I had just changed the metering rod springs, and was taking it for a test drive around the block. Ran perfect until I got to a stoplight, and then the carb took a shit.

Yes, I already know this carb is too big. Came with the car; spare me.

impulsive-RX7 · 06-18-2008, 07:18 PM

Damn, what happened to all the carb gurus?

Well the Edelbrock tech seems fairly confident that the problem is too much fuel pressure, but I'm not so sure. Unless my fuel pressure reg is prone to catastrophic failure. Although I don't actually have a gauge, just one of those Mr Gasket regs with the preset notches on it.

He also suggested sunk floats,debris in the needles & seats, or low manifold pressure causing the metering rods to stay open.

I didn't think it would be sunk floats, high fuel pressure, or low manifold pressure because the car was running fine just previously. I think those issues would have shown progressive symptoms.

Today I took the air horn off to look for debris and check the floats. I didn't find any debris and the floats are not busted. So I put the carb back together.

Then I just simply tried to start the car. She did start and run. I observed the carb for signs of flooding again, but it didn't happen. She ran fine, I let her warn up and then shut it off.

If the fuel pressure regulator had failed, did it magically fix its self? I think it must have been some debris holding the needle open.

Discuss.

PercentSevenC · 06-19-2008, 12:55 PM

Yes, probably a piece of debris. Just keep an eye on it in case it happens again. Or the floats could have gotten stuck, and taking the top off fixed it. That happened a couple of times on my 45 DCOE. (It's even worse on a sidedraft; it pours fuel all over your engine in addition to flooding it!)

Jeff20B · 07-07-2008, 12:18 PM

Did you ever find a solution to your problem?

impulsive-RX7 · 07-08-2008, 09:05 AM

Ya know, it hasn't flooded again. It seems like it was just a stuck float or needle. I drove it around the block last weekend and she ran great, but I don't trust it enough to leave the neighborhood. I'm just waiting on getting around to the engine swap now anyway.

Jeff20B · 07-08-2008, 12:27 PM

It just seems to be a quirk of these carbs. The one I'm using had a mega-rich problem during idle once. It belched black smoke out the muffler and I had to keep reving it to keep it running, which obvously made it even richer due to the accel pump shot. Anyway whatever it was cleared in a few seconds and has been running fine since. I think a chunk of debris from the tank or inside one of the lines got caught in a jet, and reving it allowed the chunk to dislodge. Or perhaps it was already in the float bowl and got stuck between a meetering rod and a primary jet, and reving it lifted the rod allowing the chunk to get sucked through and out.

Rogue_Wulff · 08-07-2008, 10:00 AM

Dang, I'm chasing down a similar issue. I think I have nailed it as too much fuel pressure. The gauge reads 5.5 PSI, but it runs mega-rich at lower RPM, and once I manage to get it revved up, it clears out and will run pretty good, until the RPMs drop.
The car had a dead battery, so I had jumper cables on it. Unhooking the cables caused the fuel pump to quit, and the engine instantly started running better, but not for long. I swapped a good battery into the car, and the idle problem returned, but it would run longer than 30-45 seconds.
It currently doesn't have an FPR. I will be getting one to install, and see if that solves the problem. The FRP I am getting has a boost/vacuum reference port (Mallory 4307M). I plan to try 4 PSI at idle/high vacuum, and see what that does for it. Edelbrock says 6 PSI is recommended, but that may be a bit high for idle/part throttle on these carbs.
This is also a Edelbrock 1405 on a SE 6 port 13B, and RB intake. The carb is practically new, maybe 50 miles total drive time.

Rogue_Wulff · 08-07-2008, 11:09 PM

Finally got the car to run long enough for me to actually get out of it, and track down what was going on. Fuel dripping from the booster in the front primary. I dunno for sure if it was caused by high fuel pressure, or high float setting. I popped the top off, and lowered the floats a bit. Haven't got the carb back on yet, hafta wait for daylight. Sucks not having a garage to work in.

impulsive-RX7 · 08-08-2008, 03:27 PM

I'm fairly convinced that mine was caused by a float or needle stuck open.... Since it seems to have fixed itself.

Rogue_Wulff · 08-08-2008, 11:38 PM

I put mine back on, and the dripping was still an issue. I pulled the metering rods out, and the side in question had the spring clip on the top installed wrong. It was causing the rod to lean at a odd angle, compared to the plunger. I corrected it, but it was late enough that I didn't try starting it up to see if that solved the problem.
It was only dripping fuel while the engine was running, which leads me to believe that was the problem. The fuel was dripping from the booster, which is where it is drawn into the barrel from the jet. Plus, it was only dripping on one side, the side with the rod clip installed wrong. I believe this caused the rod to stick in the raised position.
Funny thing is, this carb had never been opened up before. This means it came from Edelbrock this way.

Which engine is your carb on? Mine is on an SE 6 port 13B with RB intake.
Carb may be "too big", but it should work ok.

impulsive-RX7 · 08-09-2008, 07:31 AM

Heh, mine is on a stock 12A with RB intake and exhaust. This carb is huge for this engine, but it's just in there until I swap in my turboII set-up. I got it tuned so it will pull smoothly all the way to redline, but It's still way too rich.

Rogue_Wulff · 08-09-2008, 08:05 AM

Yeah, 600 is a tad large for a 12A, especially a stockport. On the other hand, I'm considering a 500 CFM edelbrock and RB intake for my 12A car. It has RB header and stainless exhaust. RB suggests using a 465 on a stock/streetported 12A, and only jumps to a 600 for a bridgeport/j-bridgeport 12A. They suggest a 600 for the 6 port 13B. I just don't much care for holley carbs.
The SE also has RB exhaust, aside from the "muffler" that doesn't seem to muffle much.
The car was already equiped with all of this when I got it, but it never ran correctly. I think I may have it all figured out though. Aside from the stuck metering rod, the dizzy is also retarded 1 or 2 teeth. That would certainly explain the header glowing bright orange.......

impulsive-RX7 · 08-09-2008, 11:26 AM

My car came with the Edelbrock on it as well.

Rogue_Wulff · 08-09-2008, 11:53 AM

I can now say definatively that the fuel dripping was caused by the metering rod binding, and I suspect that was what was causing the issue that started this thread. My suggestion is, anytime the metering rods have been taken out, work them up and down a couple times after inserting them to make sure they travel freely.
The dizzy was also off by a tooth, but the bottom pully is 1/4 turn off, so that was kinda tricky to figure out.
Only remaining issue is a clogged idle circuit. Idles on one rotor, below about 1500 RPM, but once you crack the throttle open, it screams. I'll address that when I get it near an air hose.
Between the timing issue, and the carb crapping out, it was rather difficult to figure this one out. Being as I had never touched an Edelbrock carb before, added another level of difficulty to the equation

Jeff20B · 08-10-2008, 02:20 PM

Good job.

I've had the best luck with a fuel pressure setting of 5 psi.

07-08-2008, 09:05 AM	#5
impulsive-RX7 Rotary Fanatic Join Date: Feb 2008 Location: Jacksonville, NC iTrader: (0) Posts: 105 Rep Power: 17	Ya know, it hasn't flooded again. It seems like it was just a stuck float or needle. I drove it around the block last weekend and she ran great, but I don't trust it enough to leave the neighborhood. I'm just waiting on getting around to the engine swap now anyway. Last edited by impulsive-RX7; 07-08-2008 at 09:22 AM..

08-08-2008, 11:38 PM	#10
Rogue_Wulff Non Member Join Date: Jun 2008 iTrader: (0) Posts: 310 Rep Power: 17	I put mine back on, and the dripping was still an issue. I pulled the metering rods out, and the side in question had the spring clip on the top installed wrong. It was causing the rod to lean at a odd angle, compared to the plunger. I corrected it, but it was late enough that I didn't try starting it up to see if that solved the problem. It was only dripping fuel while the engine was running, which leads me to believe that was the problem. The fuel was dripping from the booster, which is where it is drawn into the barrel from the jet. Plus, it was only dripping on one side, the side with the rod clip installed wrong. I believe this caused the rod to stick in the raised position. Funny thing is, this carb had never been opened up before. This means it came from Edelbrock this way. Which engine is your carb on? Mine is on an SE 6 port 13B with RB intake. Carb may be "too big", but it should work ok. Last edited by Rogue_Wulff; 08-08-2008 at 11:40 PM..

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06-14-2008, 06:37 PM	#1
impulsive-RX7 Rotary Fanatic Join Date: Feb 2008 Location: Jacksonville, NC iTrader: (0) Posts: 105 Rep Power: 17	Edelbrock dumping copious amounts of fuel Edelbrock Performer 600cfm #1405 What would cause this carb to dump massive amounts of fuel into the engine; with no throttle input and even after the car is shut off? I mean it was literally pouring fuel into the primaries. Massive flooding. Was previously running just fine. I had just changed the metering rod springs, and was taking it for a test drive around the block. Ran perfect until I got to a stoplight, and then the carb took a shit. Yes, I already know this carb is too big. Came with the car; spare me. Last edited by impulsive-RX7; 06-14-2008 at 06:40 PM..

06-18-2008, 07:18 PM	#2
impulsive-RX7 Rotary Fanatic Join Date: Feb 2008 Location: Jacksonville, NC iTrader: (0) Posts: 105 Rep Power: 17	Damn, what happened to all the carb gurus? Well the Edelbrock tech seems fairly confident that the problem is too much fuel pressure, but I'm not so sure. Unless my fuel pressure reg is prone to catastrophic failure. Although I don't actually have a gauge, just one of those Mr Gasket regs with the preset notches on it. He also suggested sunk floats,debris in the needles & seats, or low manifold pressure causing the metering rods to stay open. I didn't think it would be sunk floats, high fuel pressure, or low manifold pressure because the car was running fine just previously. I think those issues would have shown progressive symptoms. Today I took the air horn off to look for debris and check the floats. I didn't find any debris and the floats are not busted. So I put the carb back together. Then I just simply tried to start the car. She did start and run. I observed the carb for signs of flooding again, but it didn't happen. She ran fine, I let her warn up and then shut it off. If the fuel pressure regulator had failed, did it magically fix its self? I think it must have been some debris holding the needle open. Discuss.

07-07-2008, 12:18 PM	#4
Jeff20B Rotary Fanatic Join Date: Mar 2008 iTrader: (1) Posts: 215 Rep Power: 17	Did you ever find a solution to your problem?

07-08-2008, 12:27 PM	#6
Jeff20B Rotary Fanatic Join Date: Mar 2008 iTrader: (1) Posts: 215 Rep Power: 17	It just seems to be a quirk of these carbs. The one I'm using had a mega-rich problem during idle once. It belched black smoke out the muffler and I had to keep reving it to keep it running, which obvously made it even richer due to the accel pump shot. Anyway whatever it was cleared in a few seconds and has been running fine since. I think a chunk of debris from the tank or inside one of the lines got caught in a jet, and reving it allowed the chunk to dislodge. Or perhaps it was already in the float bowl and got stuck between a meetering rod and a primary jet, and reving it lifted the rod allowing the chunk to get sucked through and out.

08-07-2008, 10:00 AM	#7
Rogue_Wulff Non Member Join Date: Jun 2008 iTrader: (0) Posts: 310 Rep Power: 17	Dang, I'm chasing down a similar issue. I think I have nailed it as too much fuel pressure. The gauge reads 5.5 PSI, but it runs mega-rich at lower RPM, and once I manage to get it revved up, it clears out and will run pretty good, until the RPMs drop. The car had a dead battery, so I had jumper cables on it. Unhooking the cables caused the fuel pump to quit, and the engine instantly started running better, but not for long. I swapped a good battery into the car, and the idle problem returned, but it would run longer than 30-45 seconds. It currently doesn't have an FPR. I will be getting one to install, and see if that solves the problem. The FRP I am getting has a boost/vacuum reference port (Mallory 4307M). I plan to try 4 PSI at idle/high vacuum, and see what that does for it. Edelbrock says 6 PSI is recommended, but that may be a bit high for idle/part throttle on these carbs. This is also a Edelbrock 1405 on a SE 6 port 13B, and RB intake. The carb is practically new, maybe 50 miles total drive time.

08-07-2008, 11:09 PM	#8
Rogue_Wulff Non Member Join Date: Jun 2008 iTrader: (0) Posts: 310 Rep Power: 17	Finally got the car to run long enough for me to actually get out of it, and track down what was going on. Fuel dripping from the booster in the front primary. I dunno for sure if it was caused by high fuel pressure, or high float setting. I popped the top off, and lowered the floats a bit. Haven't got the carb back on yet, hafta wait for daylight. Sucks not having a garage to work in.

08-08-2008, 03:27 PM	#9
impulsive-RX7 Rotary Fanatic Join Date: Feb 2008 Location: Jacksonville, NC iTrader: (0) Posts: 105 Rep Power: 17	I'm fairly convinced that mine was caused by a float or needle stuck open.... Since it seems to have fixed itself.

08-09-2008, 07:31 AM	#11
impulsive-RX7 Rotary Fanatic Join Date: Feb 2008 Location: Jacksonville, NC iTrader: (0) Posts: 105 Rep Power: 17	Heh, mine is on a stock 12A with RB intake and exhaust. This carb is huge for this engine, but it's just in there until I swap in my turboII set-up. I got it tuned so it will pull smoothly all the way to redline, but It's still way too rich.

08-09-2008, 08:05 AM	#12
Rogue_Wulff Non Member Join Date: Jun 2008 iTrader: (0) Posts: 310 Rep Power: 17	Yeah, 600 is a tad large for a 12A, especially a stockport. On the other hand, I'm considering a 500 CFM edelbrock and RB intake for my 12A car. It has RB header and stainless exhaust. RB suggests using a 465 on a stock/streetported 12A, and only jumps to a 600 for a bridgeport/j-bridgeport 12A. They suggest a 600 for the 6 port 13B. I just don't much care for holley carbs. The SE also has RB exhaust, aside from the "muffler" that doesn't seem to muffle much. The car was already equiped with all of this when I got it, but it never ran correctly. I think I may have it all figured out though. Aside from the stuck metering rod, the dizzy is also retarded 1 or 2 teeth. That would certainly explain the header glowing bright orange.......

08-09-2008, 11:26 AM	#13
impulsive-RX7 Rotary Fanatic Join Date: Feb 2008 Location: Jacksonville, NC iTrader: (0) Posts: 105 Rep Power: 17	My car came with the Edelbrock on it as well.

08-09-2008, 11:53 AM	#14
Rogue_Wulff Non Member Join Date: Jun 2008 iTrader: (0) Posts: 310 Rep Power: 17	I can now say definatively that the fuel dripping was caused by the metering rod binding, and I suspect that was what was causing the issue that started this thread. My suggestion is, anytime the metering rods have been taken out, work them up and down a couple times after inserting them to make sure they travel freely. The dizzy was also off by a tooth, but the bottom pully is 1/4 turn off, so that was kinda tricky to figure out. Only remaining issue is a clogged idle circuit. Idles on one rotor, below about 1500 RPM, but once you crack the throttle open, it screams. I'll address that when I get it near an air hose. Between the timing issue, and the carb crapping out, it was rather difficult to figure this one out. Being as I had never touched an Edelbrock carb before, added another level of difficulty to the equation

08-10-2008, 02:20 PM	#15
Jeff20B Rotary Fanatic Join Date: Mar 2008 iTrader: (1) Posts: 215 Rep Power: 17	Good job. I've had the best luck with a fuel pressure setting of 5 psi.