Daves right.

Fuel consumption likely due to idle being too rich, very snappy at idle implies its on the rich side for idling.

Cubic inch and HP numbers needed else we just bench racing here.

I've seen similar issues on an enderle cube system:

Barrel valve configured totally wrong, outlet to distribution block connected where main pill and idle poppet/fuel inlet T was supposed to be connected. = Lean.

Fuel pump not flowing as expected. = Lean.

Cube valve setup for Blower (plumbing and poppets) and blower spool in use on NA application. = Rich

Or you have return line with part of hose loose that could be clogging return line. Just saying could be. Not found here yet.

If taking wild guess would say it this POS I found in BV at idle passage. After thinking about blockage last night I was tearing into it today and found this. Remebered BV was used part of deal I made wghen selling a ht I had picked up cheap years back. Ended up keeping barrel and since it was K style and cost almost nothing.I put spool new o-rings and put on car.Just never thought about checking to see if someone had made a plug to screw in passage with needle style end to go up and plus hole. Then never would tought anyone wouyld feel need to do.

The crap you find with used parts. Should have grabbed BV off one of my old hats But had this laying around.

Dave

WOULD AGREE way past. Should be burning it up. If not for empting tank ev ery run, fuel out pipes, puke tank dumping solo cup of alky. I would agree not ashould not have enough fuel burn. Never popped stubled ar showed heat anywhere. Which why thought may be plugged or bad ignition issue. No way in hell it should be rich number wise.

As for ci 482 power wise SWAG 750 to 800 right at best. Computer programs predict more just not buying it.

So, you are saying you had no return circuit from the BV main jet?
That would explain your high pressures for the jet/noz combo.

Yea wondering how it did not hydraulic. NOT THAT I AM MAD ABPOUT IT NOT DOING . Bent a 7/16 BBC rod in Nova from car sitting on ramps of trailer and crew guy shutting off with switch and leaving shut off open. Guessing fuel drained into system and filled one cylinder, Fired car and hyrdauliced one cylinder and locked engine up.

Hope all of issue. I never assume one thing to blame ,so as not to over look something else.

Weather permitting will find out Thursday night. Track probably going to suck but blowing tires off would be welcomed. Hell litle side ways WITHOUT scuffing my vehiucle would be ok too.

and your tuneup this time will be....?

.036 nozzles 120 to 125 main jet figure should be lot closer guessing on rich side but not stupid rich. Starting with bv around 28% tune from there.

Suggestions?

Running numbers using my Gorr sheets correction for 100 psi pump was tested at. 81.6 correction since All of Gorr stuff in 150 psi. If disagree with factor like to know why? Using formula for old flow verse new flow based on pressure. If Know better and not business issue I am open to hearing if think doing wrong. Having used same system on quite a few cars for getting base and seemed to work fine. nevedr perfect but good starting point.

This message has been edited. Last edited by: wideopen231,

idle rpm between 1500 and 1800. Leakdown is likely a bit low but you can figure that out at home. No pump sizer.

I assume you have confirmed that you have idle/main jet return working.

I don't think it's been asked. What geo altitude are you racing at?

Yes checked full system for function. Normally around here DA is 700 to 1800, was -500 Sunday morning 11am and 120 3 hours later. Track at 725 alt.

Hell if bv lean I be happy SOB after fighting it all day Sunday.

Pump sizer back in box. Less lines .less chance of leak and less weight(LOL).

While have you chatting. Had idea to night of moving filter foward in line from before pump to closer to tank at and use it like inline baffle of sorts since had car shut off in shut down. Any extra pull on that with it that far aways about 8'. Fuel that should be in tank probably take care of that but I should have been born rich and that didn't workout either,

Driving to and from trailer, 1 burn out, 1 full 1/8 mile pass, should burn about 1.5 gallons, 2 if the idle is really rich. Any more and idle is too rich or something is still wrong.

Vacuum pump on this motor?

You have a fuel filter on inlet side of fuel pump?

If that is true and it is too small or restrictive that could account for some of your problems.

how can it account for too much fuel? It is biggext one I have found. 10 AN inlet and outlet. Flows enough to empty 5 gal between drive up and park almost at line.make run drive back and coast into pit.

Well now for milage issue pretty sure opening the plugged off return main jet passage will help it little,LOL Like to find Albret who plugged it ask waht reasoning was behind it.

Basically my 2.5 to 2.8 gpm system was running on 6 gpm even with butt load of main jet. Like said it should have fried piston

This message has been edited. Last edited by: wideopen231,

quote:

Originally posted by wideopen231:
how can it account for too much fuel? It is biggext one I have found. 10 AN inlet and outlet. Flows enough to empty 5 gal between drive up and park almost at line.make run drive back and coast into pit.

Well now for milage issue pretty sure opening the plugged off return main jet passage will help it little,LOL Like to find Albret who plugged it ask waht reasoning was behind it.

Basically my 2.5 to 2.8 gpm system was running on 6 gpm even with butt load of main jet. Like said it should have fried piston

Some % would have straighted it right up.

FYI, a -12 or larger tank to pump line will help things.

My head hurts trying to translate this. How does car run on the track? What is fuel pressure at finish line or at 7,000 RPM? What are your O2 or EGT at finish line? What do the plugs look like? Is it gaining any heat during the pass? How long does it take to warm up motor? You said it "Sucked in the tank" So I said you do not have adequate vent. Then you say well not literally sucked it in. How are we supposed to help you figure out what it is doing if you can not explain it in English?

So lets get back to basics.

MFI is relatively simple, you know that. It works off of pressure, RPM and Jet size. More pressure - more fuel into motor, so what is your fuel pressure? Larger nozzles - more fuel in motor and lower fuel pressure. Larger main jet on return - less fuel in motor and less pressure. (when you change main larger is your pressure going down?) if not then I would suspect return line problem. More RPM - more volume and pressure fuel pumped. More Horsepower - more fuel you need. Simply takes X pounds of fuel per horsepower. If you know those things there are people here who can do the math and tell you if you how much fuel you are putting in the motor and how much horsepower that will support.

Common problems - Leak or restriction on inlet line such as fuel filter or bad fitting. Clogged nozzles. Bad return lines. I have seen wrong barrel valves or installed wrong barrel valves. Seen wrong pressure for check valves. First thing I would do is get rid off all of those bypasses and check valves and eliminate the as many possible problems as you can. Just your basic required check valves.

Knowing that do you know what your fuel pressure is at say 7000 RPM? I use 7,000 RPM for my records as your finish line RPM is not always same. May be 1/8 mile or 1/4 mile run, may have him covered and let out a little.

You have a data logger right? What is it telling you? O2? Fuel pressure?

Do you know if your return lines are returning fuel like they are supposed to and not clogged?

Do you know if your jets (and Nozzles)are good and not some drilled out junk? I have seen lots of main jets that are stamped say .090 or something like that but have been drilled out to say a .150 or what ever.

If I remember right with .035 Nozzles and .124 return and same size pump I was at 50 PSI at 7,000 RPM with similar horsepower. What is your pressure?

When you say butt load of main jet you do realize larger the main the LEANER the motor is? As it is returning MORE fuel back to tank. With the nozzles the larger they are the richer it is. That is basic stuff pretty sure you know but we are trying to figure out what is going on and help you.

My guess right now is you have barrel valve and idle stupid fat. That just pours the fuel through the motor. Are you running "K" valve or Cube valve? I think the "K" valve is mostly used in large cubic inch blower motors so that or the valve in it may be part of problem.

Curly,
This is a classic case of the forest getting in the way of the trees.
He said his K valve was modified and found that the idle/main jet return was plugged.
Ergo, fat hog.
Fixed now he said.
Should be good to start over from scratch without a pump sizer.

FYI, with the right spool the K valve is never a problem, even on a NA 283 CI. It's advantage is that it provides a straight shot from the pump to the distribution block and it is easier and cleaner to plumb up. The larger diameter spool allows for a longer gentle idle slot which can be advantageous.
Granted, it's not necessary on many NA apps but I install it on everything for the above reasons.

This message has been edited. Last edited by: Dave Koehler,

I agree this post is thread is long and confusing. I ran a N/a SBC on MFI and it wasn't very difficult.

Also, I'd like to know why there are just two passes being made at TnT?

first off yes I know bigger means less fuel. Only 40 years playing with injection in most every form. NA,blown alky,blown fuel,A.fuel and hell one I tried on my Harley. A 145 main is stupid ,lean and should be popping like hell. Running numbers for puymp ,required fuel and should be jet.I knew something stupid happening. hell would bave ran fine if had main jet in bypass at pump instead of bv or hell of lot better.

As for confussion fell to see. Had issue with car not leaning out. Checked BV yes correct spool. Leakage fine or very close.You know the by pass blocked for that one so no help there finding a plug screwed into BV. No two jets in main,Poppet correct setting, working.Nothing to motor stopped up with too much fuel like jets or filter.Jet lean as hell with .020 to big a jet in main and a bypass it should not need. All line seemed open to return to main fule line. Then found the plugged passage so problem solved. Well at least tells why a car that ran decent number two years ago with another injector on it,but same system number wise.

Only curve ball on thread was wondering if had a ignition issue and I was blaming fuel. Has happened A thought after working to get a piece of ignition repaired that had caused a problem with cranking last year. Bad coil and being fixed now. So did enter mind as issue.

I have three injectors here witrh K style BV. One off my TA/D one two blade that bolts on top tunnel and is kind of like dual rons toilets that I msade for brothers car way back. Also one on car now. Always worked fine on NA motors with The spool changed.

This message has been edited. Last edited by: wideopen231,

why two shots? Why run the hell out of something that is not working unless find issue? If do not make cvhange to correct that seesm to why make shot? !st shot was with a throttle that never opend due to too much return spring for SLE. Never ran sle before TA cars do not have. I have WORKED ON CARS WITH BUT NOT RANor dealt with them and did not know so weak.
Second run was still turd but had throttle open at least. Did not find a fix. So why make another shot. Doing same thing expecting different result has a definition.Could have made 10 passes and would knbow car not run worth a shyt. I would be out 50 gallons fuel,oil, plugs and have even less hair.

I went .I tested ,I found a problem but could not figure why it would be. I went home. Hell only 15 minute ride at best.

This message has been edited. Last edited by: wideopen231,

5.025,5.008,4971 and 4.967 Last night with good amount of timing left on table and only half cadium off plug. Have to up shift time too since short shifting second. EGt;s running quite cool and about 4* left in timing guessing, only 35* now.Few other adjustments to make, But damn never worked this much on little injected bunch of scrap parts to get running halfass decent. Amazing how easy it is when you find the shyt that someone did A&T engineering on. Look up A&T college and will get that one.

Side note did fine two hurt pushrods from last week when ran the valves. So 6.0 with 6 cylinders and most of pump to engine not really terrible.LOL

This message has been edited. Last edited by: wideopen231,