green1
Well-Known Member
no help
New Atomix
- Thread starter green1
- Start date
-
KitCarlson
Well-Known Member
I think it is Atomic EFI. It looks like a TBI system with injectors at the throttle body. My experience is better overall performance with injectors aimed at intake valves close to ports (MPI). The TBI with properly tuned controls, may be better than carb, but not as good as MPI.
The TBI has the advantage of easier to bolt on stock 4b manifold.
The TBI has the advantage of easier to bolt on stock 4b manifold.
green1
Well-Known Member
Yep, we got it installed-3 days. Don't listen to their hype; according to their instructions, it can't be returnless, unless you live at the north pole. No way to mount the pump lower than the sump. Ran it, pump cavitates.
So, when the in-tank pump arrives next week (pull tank, drill holes in top, mount tank lower); regulators, hp hose, etc; add another day, and $500.
Even their tech admitted the advertising and video is wrong. He told us where to get the pump, and the regulator to use(not msd reg).
Forgot; to allow it to adjust timing, need their dist. (we had that and a 6al box already). But need new rotor. $40.
So far, I will give it this-we ran out of combinations of jets and rods on the Eddy, still too rich at idle; it does smell like a normal exhaust now.
So, when the in-tank pump arrives next week (pull tank, drill holes in top, mount tank lower); regulators, hp hose, etc; add another day, and $500.
Even their tech admitted the advertising and video is wrong. He told us where to get the pump, and the regulator to use(not msd reg).
Forgot; to allow it to adjust timing, need their dist. (we had that and a 6al box already). But need new rotor. $40.
So far, I will give it this-we ran out of combinations of jets and rods on the Eddy, still too rich at idle; it does smell like a normal exhaust now.
green1
Well-Known Member
Update; pump in tank (tanksinc), what a pain, had to cut out access hole in trunk floor for the fittings to stick through. Fired it up, idled good, went through the diagnostics; all good. But couldn't get the Aeromotive regulator under 63 psi. Return system, we'll try it.
Then 5 miles of country roads, from stopped, to cruise, to 3/4 pedal. Car much more responsive, and faster. Back in the shop, still letting it idle-all this new noise in the engine bay; isolated to the efi. Shut it off for 10 minutes, fired back up; noise gone.
This efi is getting 2 cherries here. Diagnostics showed no memory fo fuel pressure lost. I thought injectors only clattered with low pressure; cycle too high.
More phone calls in AM.
Then 5 miles of country roads, from stopped, to cruise, to 3/4 pedal. Car much more responsive, and faster. Back in the shop, still letting it idle-all this new noise in the engine bay; isolated to the efi. Shut it off for 10 minutes, fired back up; noise gone.
This efi is getting 2 cherries here. Diagnostics showed no memory fo fuel pressure lost. I thought injectors only clattered with low pressure; cycle too high.
More phone calls in AM.
BillGrissom
Well-Known Member
Check the simple, cheap EFI fuel setup in my 65 Dart post. I used an external Walbro pump in engine bay (just above K-frame), supplied by a 3/8" line w/ small filter. Outlet has the Wix Corvette filter/reg (56 psi) that many use ($19, O'Reilly's), w/ original 5/16" line return. Each time you change the filter, you get a new regulator. Isn't that neat?
Pump doesn't cavitate. Companies (Holley, etc) that claim the fuel pump must be at rear, below tank level are crazy. Don't they have any engineers on staff? Ran similar for years on my 65 Newport for Holley Pro-jection. Only problem is if the tank gets real low, the sloshing after a hard stop can starve the pump suction, mainly in my Newport with its wide, shallow tank. A-body tanks sort of have a built-in sump.
Those throttle body EFI's are nice since they use common MPFI type injectors, so you can try different sizes. However, they don't give the best fuel distribution as KitCarlson says. That is a mixed bag. When new, and all injectors are matched, you get great distribution with MPFI. However, as they age, clog and vary, you can get worse distribution than with "single point" injection like a carb or TBI. With MPFI, best to remove and bench-test your injectors every 100K miles to insure they match, or maybe use an IR gun on the exhaust pipes after a hard run to see if even. I don't think that hitting the intake valves is that critical. I was at a presentation by a grad student, funded by GM, long ago where they looked at injecting far upstream in the intake runner (more time to vaporize), but it didn't work significantly better so doesn't matter much. My understanding is that in "sequential injection" they try to spray when the intake valve is closed (most of the time) so it vaporizes from the hot surface. Spraying when open flows raw fuel drops in, so slightly worse emissions, but don't quote me.
What has amazed me and many others is how trouble-free electric fuel injectors have proven. When they first came out, companies assumed they would have continual maintenance problems, and there were all sorts of "injector cleaner" products and machines. Today, those products are mostly hype. There were a few problems with the earliest systems and I recall horror stories of $300/injector replacement costs (x8 for V-8 ).
Pump doesn't cavitate. Companies (Holley, etc) that claim the fuel pump must be at rear, below tank level are crazy. Don't they have any engineers on staff? Ran similar for years on my 65 Newport for Holley Pro-jection. Only problem is if the tank gets real low, the sloshing after a hard stop can starve the pump suction, mainly in my Newport with its wide, shallow tank. A-body tanks sort of have a built-in sump.
Those throttle body EFI's are nice since they use common MPFI type injectors, so you can try different sizes. However, they don't give the best fuel distribution as KitCarlson says. That is a mixed bag. When new, and all injectors are matched, you get great distribution with MPFI. However, as they age, clog and vary, you can get worse distribution than with "single point" injection like a carb or TBI. With MPFI, best to remove and bench-test your injectors every 100K miles to insure they match, or maybe use an IR gun on the exhaust pipes after a hard run to see if even. I don't think that hitting the intake valves is that critical. I was at a presentation by a grad student, funded by GM, long ago where they looked at injecting far upstream in the intake runner (more time to vaporize), but it didn't work significantly better so doesn't matter much. My understanding is that in "sequential injection" they try to spray when the intake valve is closed (most of the time) so it vaporizes from the hot surface. Spraying when open flows raw fuel drops in, so slightly worse emissions, but don't quote me.
What has amazed me and many others is how trouble-free electric fuel injectors have proven. When they first came out, companies assumed they would have continual maintenance problems, and there were all sorts of "injector cleaner" products and machines. Today, those products are mostly hype. There were a few problems with the earliest systems and I recall horror stories of $300/injector replacement costs (x8 for V-8 ).
green1
Well-Known Member
It turned out to be a restriction in the return line. This car runs so much better.
-
