jerry01

Oh and on my fuel system I will be running the full return line system. I'm actually picking up a 22 gallon tank to replace my 16 gallon and it'll have an intake pump and a full return. I've got an aeromotive regulator in hand already to plumb into the return line.

Stangatic

@ Jerry01- Yep that's no typo! I wasn't trying to achieve/nor looking to achieve a better MPG but I went from 15mpg on my carb to 20 - 22mpg on the EFI. Now on that note, my carb was setup by a dyno shop to get the most HP they could and the carb ran rich constantly. This was the main reason for going EFI as I was tired of getting high on 93 octane while driving down the road. In addition, my transmission was set up with a .59 overdrive. This was the worst mistake I made in terms of my transmission as the .59 overdrive is more for road racing and going over 130MPH. With my gears, tires, and this transmission, at 70MPH I think I am turning around 1,600 - 1,800 RPMs which is a little low and the engine/cam doesn't care for it too much (might go to 4.11). but the end result was great MPG when on a 300+ Mile cruise. Checked MPG the old fashion way and received between 20 and 22 MPG both ways.

After posting my last post I took the car out and drove the hell out of it. No issues, but after spending a lot of time on the MSD forums, I think too am going to put the return line on as the new instructions state. Everyone that had the system on the old way raves about how big a difference it makes with the return line.

LASTLY Check your weiand intake manifold. Does it have two coolant ports for sensors? the MSD EFI like other EFIs will need its own port. If you don't have two ports, then you will have use the port for the gauge in the car which would then result in not being able to determine the temp without actually looking at the EFI display. Something that I find a bit annoying. I had a professional product intake on my car when I originally installed the EFI; it had two ports, but after having a tone of vacuum issues I found out my new intake was warped...... now I am running an edelbrock with no interior gauge.

jerry01

Stangatic, Very impressive!!! I was hoping to see some improvement in MPG but wasn't super optimistic. Still not going to hold my breath but I'd be stoked to see those kind of numbers with mine!

I've got a the T5 with the 0.63 5th gear, 3.00's in the rear and a pretty mild/stockish but brand new 302 that I'll be doing the full MSD setup on here probably early June. I'm saving pennies for the fuel system stuff to support it and I'm replacing my whole tank with a larger 22gal one with the in tank pump setup. I've already physically got the entire EFI and MSD system sitting in the garage ready to go...

jerry01

BTW, I looked and the wieand intake only has a single port... I likely will be in the same boat as you unless I can figure something else out for a 2nd port option.

Matheus Chidiac Marchiori

Sorry to up this topic but we dont have until now much info about the problems and solutions of MSD ATOMIC EFI.
Im not live in the U.S so its very dificult to call them and ask about the problems with the system.

I have a sbf 302 4020 bore with a big cam. Its a 294s Comp cams. Using Victor Jr, all MSD ignition system(6AL Digital, Blaster SS...) and atomic efi controlling timing. Have edelbrock e-street heads too.

Questions:
Engine displacement - Do i need to use 302 or 304 ?
Camshaft type - My car doesnt idle with performance style, only on mild. There is a problem on there? I already change the screws and nothing work with performance. And i do not can get the IAC between 5-15(t5 transmission), its 20 or higher or zero. I dont know why, know its zero, with i change a little bit the rpm increase.

Some issues with backfiring on decel only. After push hard in first and second gear in some point the atomic appears to be lean and a backfiring occurs.
Initial timing is 18 and final 36.
Fuel pressure about 60psi, on the decel 55psi+-
pump squirt 27%
power valve enrich 21%
vaccum ported
vaccum advance 0
rpm target - 950 (idle with 1100)
total rpm - 2300(thinking to change for 2000) what are you guys think?

MonsterBilly

I have Atomic on my Mustang, Fitech on my Bronco. The Atomic is far better in every way.
I have a 347 with T5. I am getting about 17 MPG and I drive it like a maniac.
I do not have the atomic controlling timing. I have a mechanical advance ProBillet with a 6 al. My car runs great. The only issues I had was the initial tune, my cam is too big and the fuel return.

I have to run it on stock cam profile, i have a x303 cam with too much lift for the Atomic.
I had to add off throttle fuel to keep it from stalling when i would decelerate

Lastly, I had to add the fuel return. It is too hot here in AZ for the frame mounted pump. It would overheat and leave me stuck until it cooled off.

it has been dialed in for a year and runs fantastic.

NOW IF I COULD JUST ELIMINATE THE DAMN VIBRATION I AM BATTLING. UGH

Matheus Chidiac Marchiori

"I had to add off throttle fuel to keep it from stalling when i would decelerate" -

How you do that?

MonsterBilly

I dont quite remember, but I will look through my notes and see what I can find.