[70f400]

1970 firebird. 425-450 h.p. 462ci. I just finished a 2 year frame off resto on this car been driving it a little and I'm pretty sure it's not getting enough fuel. It has new 3/8 stainless line from tank to passenger side frame rail in the engine compartment. im looking at the Rob Mc fuel pump. Any other fuel pumps you would recommend? I have never used the AN lines and looking for help on how to plumb from existing 3/8 line to pump and from pump to carb. I currently have 3/8 rubber fuel line from the passenger side frame rail connected to a cheap part store fuel pump and a new steel pump to carb line to my Q-jet. Want something much safer then that much rubber line. Is there another fuel pump that we'll work with my steel pump to carb line or do I run Braided there as well.

[AdamIsAdam]

My research led me to a RobMc 1/2 pickup, pump, filter and I'm about to install my new 1/2 stainless line end to end to feed my Qjet atop a 469. I'm interested in what others post as well.

[78w72]

heres my experience with fuel issues on a q-jet 500+hp 467 & early 2nd gen bird. asfter talking with cliff & other members here i decided at a minimum the engine needed the 1/2" pickup & 1/2" or -8 braided line from tank to pump... 3/8 is not enough for most cars with these big engines & a q-jet. holley guys can get away with it a little easier because of the big dual fuel bowls, not the case on a q-jet.

i used an edelbrock pump because it was free & they claimed it was good to 600hp with adequite lines. & indeed it did supply the engine on the dyno ok & does fine on the street. however, once i did some drag strip runs with good tires, i noticed the starvation issue many talk about, its good to 11.7 at 118mph but once i try a harder launch or higher rpms it will cut out at the top of 1st going into 2nd gear.

so i suggest the robbmc 550 pump for your application & upgrading to bigger tank to pump lines & pickup, the better pump might offer some improvment but the restriction is in the small lines & pickup IMO. or at least they are a big factor. the stock steel line wont work with the robbmc pump, need to conjur up new fittings & line routings, the outlet is on the bottom of those pumps which must be required in the design because it sure does make it difficult to run the outlet line when its pointing straight down at the ground.

do you do any drag racing or just street use? i wouldnt think youd have a problem on the street. maybe the pump is the culprit, might try a full size canister airtex type pump if you have the small canister type. on an old mild 455 powered 78 t/a i used to have the 3/8 & stock big canister pump did fine on the hardest street racing you could do.. but that did have a holley carb.

[leeklm]

Before you start throwing money & time at the potential issue, you could first borrow a holley carb from someone and see if the problem persists, or changes. Or better yet, install a fuel pressure gauge and watch to see what happens when running the car hard.

If you do conclude it is a fuel issue, another option is the RobbMC power surge system. You can leave your 3/8 pickup & line in place, and have the benefit of an electric pump to eliminate vapor lock, etc. Only downside IMO is finding a place to mount the powersurge.

[Joel Koontz]

Agree with the suggestion to install a fuel pressure gauge and observe during full throttle operation.

If you don't mind the cosmetics and have a good place under hood to install it, the RobbMc Power Surge should definitely supply all of the fuel that you need.

You could also install an electric pump at the rear of the car. Much easier to push fuel than to pull it so the 3/8" line should be adequate at your power level.

Tanks Inc, In-Tank setup http://www.tanksinc.com/index.cfm/pa...rod/prd411.htm should work well.

[JSPONT]

What pump do you have now? I went with a Robmc 1/2 pick up, 8an all the way to the regulator, 8 an return line, But I ran an electric pump.
Robmc stuff is top notch. Great to deal with too.

I would buy his pump and run braided line from the pump to the carb. The black braided line is great looking not as stand out as the stainless.
Did you modify the carbs inlet? Cliff R taps them npt so you can put an 8an fitting in them.
Once I went with what I described, my car did not lay down anymore. Top of third gear it would run out of fuel before I did the mod. I spoke to Cliff on this, He gained 3 tenths on his car just from a fuel mod years ago.
The q jet if done right can handle it no problem. My friends car runs 9.60 1/4 with a qjet so you have to able to get it to work.

[FrankieT/A]

My experience: I installed the RobbMc 1/2" fuel sender (top notch btw). I installed 1/2" stainless line all the way to my Robbmc 550 pump and 1/2" metal line straight to my Qjet. I still have starvation problems. I had to install an electric pusher at the rear to overcome. With the Robbmc pump alone my fuel pressure is very erratic runs down to 2-3 lbs. at 4000 RPM. The electric pump dialed down to 7 PSI. cured the problem, which I only use during spirited driving. When I get to the top of third the car just noses over(can be very embrassing)I really thought the Robbmc pump would be the cure all, but is not.

[AdamIsAdam]

Both RobbMc and cliff, and others, say to be sure you're racing with as close to a full tank of gas as possible to avoid fuel starvation. Frankie, can you recall if you had starvation with full tank? Just curious.

[steve25]

At around 500 hp it's not just the size of the line that is the issue, but the G force on the fuel in that line on acceleration! The fuel pump at the tank needs to maintain at least 12 psi up at the regulator inlet near or at the motor!

At the 590 hp level with motor of more than 460 cid a Q jet even on a static Dyno test the small size of the fuel bowl just can not keep up and starts showing signs of unstable jetting, no less if it had to do so while encountering G forces !

[70f400]

I will give RobbMC a call. I was given a holley 12-389-11 mechanical pump. I may try this before ordering the Robb Mc pump and replacing all of my lines. The current pump I have on there looks like a 2bl pump just no return line. 70 norwood cars did not come with return lines I believe. If this helps I know I am heading in the right direction.

[78w72]

Originally Posted by FrankieT/A

I had to install an electric pusher at the rear to overcome.

what pump did you use for a pusher & how did you plumb it in? bypass valve or does the mech just pull through the elect? do you use a regulator?

[70f400]

I don't have an electric at all right now.

[78w72]

question was for frankie....

[FrankieT/A]

I never noticed it with a full tank. But over half for sure.

One thing I did do when I ordered my fuel sender from RobbMc was ordered it with two supply lines and one return. So, originally I plumbed the mechanical from one supply to the front of the car using all 1/2" stainless. The stainless line comes from Inline Tube. My original idea was to use one supply line for the mechanical pump and one for the NOS. It didn't work out that way because the Robbmc 550 fuel pump couldn't even supply the engine's demands. The Robbmc fuel sender is quite a nice piece, I'll give them that!

Ok so, the mech fuel pump is connected to one supply of the sender and the electric pump is connected to the other. The electric pump is a Holley Blue. Keep in mind everything is 1/2". You can't push or pull through a Holley pump. So I use a one way trap to bypass the electric pump so the mechanical can pull around it. Everything is right in front of the tank: Holley pump, one way trap and fuel pressure regulator.

[ahnuld]

The regulator is supposed to be as close to carb as possible I thought. Dan

[FrankieT/A]

Yes, It should be. But Im going through the mechanical and it gives me a steady 7 1/2 lbs. at the carb. I only use the the electric for spirited driving and NOS blasts. Without the electric pump; just using the Robbmc alone my fuel pressure bounces like crazy then at about 4000 RPM it drops to 2 or 3, and car noses over. I wouldn't even attempt a NOS shot on Robbmc alone.
Technically the RobbMc should handle everything by itself.

[68azbird]

Originally Posted by FrankieT/A

Without the electric pump; just using the Robbmc alone my fuel pressure bounces like crazy then at about 4000 RPM it drops to 2 or 3, and car noses over. I wouldn't even attempt a NOS shot on Robbmc alone.
Technically the RobbMc should handle everything by itself.

I have the same problem. Fuel pressure drops to 3psi and I have -8an from tank to carb.

[FrankieT/A]

Originally Posted by 68azbird

I have the same problem. Fuel pressure drops to 3psi and I have -8an from tank to carb.

Are you using RobbMc?

[68azbird]

Yes

[FrankieT/A]

So, you have the same problem.......RobbMc is not the cure all. Incidentally mine 1/2" all the way to the carb. When I told Robb about it they wanted me to send back the pump. It was brand new then. How about you test a new pump and send it to me....charge me again to guarantee the old pump return. NO they want my car to be down while they work it out. I'll pass I drive my car too much.