Fuel systems

Can anyone tell me what the formula is for timing the amount of fuel out of my system? 1 gallon in how many seconds? I replaced my old BG400 system, that crapped out @e-town divisional, with a Weldon system, but still getting a miss fire or popping soon as I hit high gear. Never does it in 1st or 2nd. This is something new that just started happening. It'll sometimes backfire when I try starting the car, whether cold or hot. Very puzzling. All replies are appreciated. Thanks. Dave SS/ea #1355

gallons per minute is typically how it's measured.

You can time how long it takes to pump out one gallon and divide 60 by that number to get GPM.

Or are you asking how to determine how many gallons per minute your engine needs? Which is another issue all together.

Thanks for the reply, I'm just trying to see if I may have a collapsed hose somewhere, by how much fuel is pumped in how long, even though my whole system was changed. It did this w/BG400 system, but pump died, and that's what I attributed miss/popping to, but it's happening w/Weldon system as well. Dave SS/ea #1355

typically starvation tends to show up in high gear as the demand outruns what the fuel system can deliver. Is the RPM and the in hg vac level the same in the different gears when its OK and when its not OK? the backfire sometimes when starting and that it just started makes me think that it ain't fuel unless a line got crimped or the pump is crapping out & I dont think there is a crimp and you did replace the pump. Is there a sock on the pickup & is it not plugged? To confirm delivery I would rig a gauge & see what you have at the carb INLET at the point (rpm/gear/in hg) that it misses at and is that a pop out the carb or a pop out the tailpipe(s)? I would sub in another coil & if that ain't it then put the orig coil in & sub in another ECU. that'd be my bet (coil or ECU). Holler how it turns out

No sock in fuel cell we replaced the whole system from trunk to carb regulator including lines. When it misses/pops it's coming from under the hood. I'm trying to eliminate the obvious, before tearing apart. I have an mad tester & got the ignition to fire & everything seems fine, blue/white spark to over 15k. But what surprised me was a suggestion that I try the trains brake, so I set the tester at 8,700 jumped into the car, touched the button & the ignition stopped working, at least I think it did, I really need another set of eyes to confirm. But the trans brake button has some free play in it, so I'm wondering if it's jiggling once in high gear enough to cause a short type of symptom. I'm about to jump under car & check the wiring from trans to button for shorts. Then once I have a helper check voltage on trans brake button for a big voltage drop instead of milivolts. This is puzzling as all hell. Thanks again for the replies keep me coming. Dave SS/ea #1355

I've had 2 coils go out & in both cases once I got the car/truck back home in the parking lot (coil had cooled) I was able to generate copious sparks out of the coil center terminal (coil wire held 1/4 from ground) by dragging the male tip of the body half of the dist pickup across the metal intake (key on of course). they popped/missed/backfired (in the carb) & finally died & on the car deal after acting up for a half hour on the road on the way home it finally exploded the muffler and the guy in the next lane just about wrecked getting out of the way & likely thought he was being shot at. EDIT actually the backfire was out the tailpipe not the carb now that I recollect

Thanks for the coil suggestion, I have another 1in my trailer, but that doesn't explain the ignition cutting out when I touch the trans brake button. Wondering if the solenoid may have gone bad. Dave SS/ea #1355

I ain't familiar with a transbrake system but can you disable it & see if things go back to normal. As you know it is definitely having an immediate effect on the ign. EDIT you said turning on the trans br stopped the ign. is that as in made it die or is it making it act up with the same symptoms happening when going down the track? & if so (especially the 2nd one) that would easily point to the TB as the culprit

I know what ur saying, I was alone last nite, had mad buzzing @8700 jumped into car but sound had died down real low when I hit the button it sounded like it stopped & when I let go it came on again. But I need another set of eyes for assistance, working out of a 1 car garage makes getting in & out of car difficult. Called my daughter she might swing over & lend a hand. Don't keep any suggestions to unselfish keep firing them at me. They might help thanks. Dave SS/ea #1355

I don't know that system so I'm about on empty here. What exactly is turning 8700RPM !

With the engine not running. The voltage drop when the TB was activated could be enough to cause the ign to drop out. Before the next test. Make sure you are starting with a freshly charged battery. Could make the difference.

Digger73 (Mike)

With the mid tester u can activate the ignition to run as if the engine was running, tach works, so u can bring it up to any rpm Without the high speed chip I was able to make the msd go as high as 15k, that's a sight on the test plug, so tapping the trans brake button, @8700 rpm I was able to make the ignition shut off with each tap. Think trans brake switch or tranny solenoid is bad. Jiggling wires while that high doesn't do anything. Dave SS/ea #1355

Fuel pressure gauge where you can read it going down the track.

Fuel pressure gauge right in front of me. 1st & 2nd gear it stays right at 6 lbs 3rd gear when it starts popping goes to 5 3/4 lbs. don't think it's fuel but I still want to do the timed fuel test, 1 gallon in how many seconds. Keep the ideas coming, thanks. Dave SS/ea #1355

You tuning a two step?

Running a 3 step. Tested msd, I have 7al 2, with nothing plugged in & tested with msd tester, unit worked right up to 9k and beyond with bright blue/white light. Then put in 8800 high speed chip & tested, unit worked perfectly. Then connected 3 step with rpm module & unit worked perfectly, with 9k chip installed. I had the msd redone & updated by pat at tech west racing, several years ago, & just spoke to him yesterday, followed his instructions to the letter and, can't find anything wrong except tapping against the trans brake button makes the msd shut off when pressed & on again when released, so ordering another button tomorrow & hopefully that's the problem. Had my daughter watching test plug while unit was firing at 8700 rpm while I pulled, jiggled yanked on trans brake wire from tranny right thru floorboard but no change. Only button, but could also be internal solenoid. Thanks for the suggestions. Dave SS/ea #1355