420A: 420a-T Fuel Setup Help

[Peej420a]

So im about ready to turbo my 420a (i have the 97 and 95 engine and ECU). I have been searching this site for about 6 months, learning about turboing the 420a befoore i became a member. As far as fuel goes, I have: 12:1 FMU, AFPR, Walbro 225 Pump, and 460cc injactors. I am really uneasy about Playing with wires and my ecu, so MS is out of the question for right now. I am looking to run between 8psi and 15 psi. would this setup be safe/ok for that amount of psi? I am Going to upgrade my plugs wires and coil for a better burn and a wideband. Please ask if any other info is needed, thank you

[LeeSD1]

Originally Posted by Peej420a

would this setup be safe/ok for that amount of psi?

No...For one, you dont want to run more than 8psi on a stock motor, especially not 15psi. 2nd, a 12:1 FMU and AFPR isnt a reliable way of controlling fuel because with 460cc you will be Dumping fuel.
MS is your best option. IF your iffy about wiring then you could start off with a MS Fuel Only setup and leave the stock ECU controlling timing and idle and everything else, while MS just controls fuel. Then later on if you want you can hook up Spark control.

[Peej420a]

Originally Posted by LeeSD1

No...For one, you dont want to run more than 8psi on a stock motor, especially not 15psi. 2nd, a 12:1 FMU and AFPR isnt a reliable way of controlling fuel because with 460cc you will be Dumping fuel.
MS is your best option. IF your iffy about wiring then you could start off with a MS Fuel Only setup and leave the stock ECU controlling timing and idle and everything else, while MS just controls fuel. Then later on if you want you can hook up Spark control.

I was planning on running only 8 psi on the stock motor. I am currnetly building another block. I have the JE 0.020 over/Eagle Setup, Ported head, MLS HG, ect...
anyways,
Couldnt i just use the AFPR to turn the idle pressure down so i wont flood?

Would it even be possible to use that kind of setup for 10psi and stock injectors?? Just untill i get the cash for MS or Portfueler? like I said, Im Really trying to stay away from the wires. Some have told me that this would work and others quote you. Its just a DD. College guy on a College Budget.

[LeeSD1]

Stock injectors will be maxed out at 10psi and you will run lean. IMO the safest route on a budget would be to go with bigger injectors(370cc or similar size) stock ford injectors work and a SFMU. With a super FMU you can adjust static and boost fuel pressures. Theres a lot of good info on using the SFMU with larger injectors for 8psi just search on here.
BUT if your building a motor then Im Sure you will want to up the boost and run more power so why not do it right the first time and go MS? None of the fuel setups for the 420a are sufficient enough for proper tuning. MS will allow you to tune the fuel in right, its kind of pointless to build a motor and not have a way to tune it because without a proper tune you can easily blow a nice brand new motor.just sayin.Plus theres tons of how to articles on installing a MS on a 420a as well all the tech support provided online for MS.

SFMU

[Peej420a]

Update* My dad is friends with a guy at a shop. He tunes track cars Via (Unknown). He says that he will tune my car whenever i get ready. Now, i assume that he is going to try to log/Remap/Flash my ECU. I have heard of people Logging their 420a but is it possible to remap or flash its ECU? IF so, I was going to take it to him and let him get to work.

[Gruff511]

You can run normal diagnostic logs via OBDII connector and laptop but our ECU's can Not be reflashed or tuned.

[Peej420a]

Originally Posted by Gruff511

You can run normal diagnostic logs via OBDII connector and laptop but our ECU's can Not be reflashed or tuned.

Just as I expected. I have no idea what the tune guy was planning on doing, but I knew that wouldnt work, otherwise i would have tried it myself a long time ago, but I still have SOME faith in him. lol Mabey he can tune my "horrible" fuel setup or something.

But like I said, some people say "It will work" Others quickly Say "Go with MS" Im just looking for more opinions at this point. The Yay's Have done it before and the Nay's Wouldnt risk it.

8psi setups that i have seen work with 420a
1. FMU, Stock injectors, stock Fuel Pump(Strain fuel pump & Injectors)
2. Bigger injectors, Stock FPR, Stock Fuel Pump(strain fuel pump)
3. FMU, Bigger injectors, 255 Fuell pump, 8psi+ (No Problems, ran a little rich)
4. Stock Everything(Ran good for about 2 yrs)
5. MS or Portfueler(Runs,but Check engine lights everywhere)

[LeeSD1]

Originally Posted by Peej420a

Just as I expected. I have no idea what the tune guy was planning on doing, but I knew that wouldnt work, otherwise i would have tried it myself a long time ago, but I still have SOME faith in him. lol Mabey he can tune my "horrible" fuel setup or something.

But like I said, some people say "It will work" Others quickly Say "Go with MS" Im just looking for more opinions at this point. The Yay's Have done it before and the Nay's Wouldnt risk it.

8psi setups that i have seen work with 420a
1. FMU, Stock injectors, stock Fuel Pump(Strain fuel pump & Injectors)
2. Bigger injectors, Stock FPR, Stock Fuel Pump(strain fuel pump)
3. FMU, Bigger injectors, 255 Fuell pump, 8psi+ (No Problems, ran a little rich)
4. Stock Everything(Ran good for about 2 yrs)
5. MS or Portfueler(Runs,but Check engine lights everywhere)

You cant tune the 420a ECU for a boost application because it cant read boost.
With a boosted application you Never want to run with the stock fuel pump. They are too weak and small. Those setups you listed may work but you will not be able to tune them into the right AFR's besides MS of course. Me personally saying to go MS because I was in the same situation when I put on a turbo. I first used just a 12:1 FMU with 255 fuel pump on stock injectors and ran super rich for a little then it broke and I went super lean for a while. Then switched to a vortech sfmu with 370cc injectors and safc neo and it ran better on this setup but was still hard to dial in the fuel with the sfmu. I then went MS because the stock ecu kept giving me problems shutting off and what not, so I was kind of Forced to go MS full standalone and remove the stock ecu. btw: if your looking to Not have any CEL I wouldn't modify it.

[Peej420a]

Originally Posted by LeeSD1

Stock injectors will be maxed out at 10psi and you will run lean. IMO the safest route on a budget would be to go with bigger injectors(370cc or similar size) stock ford injectors work and a SFMU.

SFMU

Will any Ford injectors work? Ive read on other threads and forums that they worked, just not sure if there is a specific year model or Car Model. Finding the injectors is eas, just stay away from anything over 370cc? Ill Just sell the RX-7 460cc Injectors that i have.

BTW you guys are really giving me some great info on my little subject. I appriciate it and I thank you. Please keep your opinions and experiences rolling in!

[stracer107]

You are also going to need a fcd ( fuel cut defender) I would strongly recomed a bigger fuel pump. I have heard of guys runnig stock 4g63 fuel injectors 450s. I havent tried it as I got my awd before I got around to turboing my rs. But I would also strongly recomed a fuel tuning source ms would be best so you could upgrade later. But there are others you can use. Just my .02

[Peej420a]

Originally Posted by stracer107

You are also going to need a fcd ( fuel cut defender) I would strongly recomed a bigger fuel pump. I have heard of guys runnig stock 4g63 fuel injectors 450s. I havent tried it as I got my awd before I got around to turboing my rs. But I would also strongly recomed a fuel tuning source ms would be best so you could upgrade later. But there are others you can use. Just my .02

I have a bigger fuel pump, so thats not going to be a problem. While researching, i read about the 95 fuel system and ECU not needing a FCD reason being that they dont have fuel cuts. I dont know how true that is, but if it is true then i will use that setup (i have both 95 & 97 Fuel setup). As for 4g63 Injectors 450s, I have those including the whole motor. but if i put thos in the 420a i would need a resistor pack and a way to tune those huge injectors ...So i was planning on using a slightly bigger injector like 310cc-370cc (like the guy stated above) so that my stock ECU would still work fine with them. Thanks for the great input.

[LeeSD1]

Originally Posted by Peej420a

So i was planning on using a slightly bigger injector like 310cc-370cc (like the guy stated above) so that my stock ECU would still work fine with them.

I Only mentioned using those injectors with a SFMU(Super FMU or 'rising rate afr') its not about the ECU being able to only work with those, the ECU will run your 460cc's but those are just way too big for your setup. IF you search theres a lot of threads on people using the stock 4g63 450cc with a SFMU but they then use a S-AFC to control the injectors at ''Idle'' BUT since the dsm 450cc injectors are so big for what you need them for you will have to drop your idle fuel pressure Way low to dial in idle right, and even at WOT injector duty cycles are pretty low I dont remember exactly what it was. So that is why I used 370cc so I wont need to have such low fuel pressures at idle and stoich and in boost.
Are the rx-7 460cc injectors you have the High impedance ones or Low?

[Peej420a]

Originally Posted by LeeSD1

I Only mentioned using those injectors with a SFMU(Super FMU or 'rising rate afr') its not about the ECU being able to only work with those, the ECU will run your 460cc's but those are just way too big for your setup. IF you search theres a lot of threads on people using the stock 4g63 450cc with a SFMU but they then use a S-AFC to control the injectors at ''Idle'' BUT since the dsm 450cc injectors are so big for what you need them for you will have to drop your idle fuel pressure Way low to dial in idle right, and even at WOT injector duty cycles are pretty low I dont remember exactly what it was. So that is why I used 370cc so I wont need to have such low fuel pressures at idle and stoich and in boost.
Are the rx-7 460cc injectors you have the High impedance ones or Low?

First off, Thank you sir. Second, I believe the injectors are High Impedance 460cc Denso Red tops. Still kinda thinking abbout using them untill i get some 30lb ford injectors. Probably wont put those in though. Postponing the turbo untill i can find a shop that will make a custom downpipe for me. I may just do it myself, using some flex exhaust pipe till a shop takes me in.

[Peej420a]

Originally Posted by LeeSD1

No...For one, you dont want to run more than 8psi on a stock motor, especially not 15psi. 2nd, a 12:1 FMU and AFPR isnt a reliable way of controlling fuel because with 460cc you will be Dumping fuel.
MS is your best option. IF your iffy about wiring then you could start off with a MS Fuel Only setup and leave the stock ECU controlling timing and idle and everything else, while MS just controls fuel. Then later on if you want you can hook up Spark control.

Has anyone tried Split Second EMS?

Fuel-Timing Calibrators

Never heard of it untill i snooped around a few other forums for a while. I didnt read it through, but it cought my eye. Mabey some of you have used it, but everyone seems to shove MS after every sentance. Im leaning towards MS in the near future, but this made me very curious.

[Josh97eclipse]

FCD's suck, mine just quit because of the heat in the bay. Save that hassle and get a missing link.

[VelocitàPaola]

Originally Posted by Josh97eclipse

FCD's suck, mine just quit because of the heat in the bay. Save that hassle and get a missing link.

Sounds like a generalization. I've never had that problem.

[LD25Delta9]

Here's a link that may help you out. It doesn't cover install or what parts you should use, rather what parts are needed for certain setups. End-All Parts List to Go Turbo

I hope it helps. Before you get into SFMU and SAFC, do some research. The cost of those two things and the required work is much more than that of the MS route.

[mzdzoom]

Originally Posted by LeeSD1

You cant tune the 420a ECU for a boost application because it cant read boost.
With a boosted application you Never want to run with the stock fuel pump. They are too weak and small. Those setups you listed may work but you will not be able to tune them into the right AFR's besides MS of course. Me personally saying to go MS because I was in the same situation when I put on a turbo. I first used just a 12:1 FMU with 255 fuel pump on stock injectors and ran super rich for a little then it broke and I went super lean for a while. Then switched to a vortech sfmu with 370cc injectors and safc neo and it ran better on this setup but was still hard to dial in the fuel with the sfmu. I then went MS because the stock ecu kept giving me problems shutting off and what not, so I was kind of Forced to go MS full standalone and remove the stock ecu. btw: if your looking to Not have any CEL I wouldn't modify it.

Thats a little incorrect about that the 420a ecu doesnt read boost because it actually does. I am currently using a bluetooth obdII scanner with the torque app on my droid and it gives me a boost reading

[Peej420a]

Ok ok, you guys won. I Will be going megasquirt in the near future (After college books are paid for $$$). Gonna do alot of researching and reading up on tuning and the MS manual. I have 3 guys who know how to install and tune it for me when i get it. Ill just go with my dingy little setup untill then. Oh yea, just got my wideband in a few days ago and scangauge II. Still gotta get a shop to make a custom downpipe for me. Thanks for all the knowledge guys. Anyone else wanna throw in the .02 before I figure out how to close this?

[grothe3297venge]

Originally Posted by mzdzoom

Thats a little incorrect about that the 420a ecu doesnt read boost because it actually does. I am currently using a bluetooth obdII scanner with the torque app on my droid and it gives me a boost reading

... Proof or I'm raising the BS flag.

[LD25Delta9]

Originally Posted by grothe3297venge

... Proof or I'm raising the BS flag.

+1 on that. let the PM's commence.

[LeeSD1]

Yeah his app on his phone is lying to him lol

[mzdzoom]

its never a positive boost because your right there is no turbo so its always negative but the computer still reads intake pressure

[bryanwheat]

Originally Posted by mzdzoom

its never a positive boost because your right there is no turbo so its always negative but the computer still reads intake pressure

Of coarse it reads vacuum, that is the job of the map sensor.

[mzdzoom]

Originally Posted by bryanwheat

Of coarse it reads vacuum, that is the job of the map sensor.

right so there for if u were to put a turbo on the car it should give u a positive boost read out

[grothe3297venge]

Originally Posted by mzdzoom

right so there for if u were to put a turbo on the car it should give u a positive boost read out

No, it wont give a "positive" read out. Once it sees positive pressure you will endure fuel cut..

[LeeSD1]

Originally Posted by grothe3297venge

No, it wont give a "positive" read out. Once it sees positive pressure you will endure fuel cut..

Exactly, as the ecu was programmed for N/A and not a turbo, if it reads "positive" boost pressure or anything more than atmospheric pressure then it will cut off, the stock map only goes up to 102Kpa i think it was.

[Peej420a]

Ok, So I did some more thinking about "Fuel". I have a 97' Returnless Fuel system. Would I Still need and FMU Since I have the 255LPH Fuel Pump? There is Nowhere for the Pressure to go once the pump puts the the pressure in the rail right? (also have an AFPR) Its still doesnt seem to make sense to run a return line. (If the answer is out there, I cant find it.)

[VelocitàPaola]

Originally Posted by Peej420a

Ok, So I did some more thinking about "Fuel". I have a 97' Returnless Fuel system. Would I Still need and FMU Since I have the 255LPH Fuel Pump?

Yes, you need both, not one or the other.

Originally Posted by Peej420a

There is Nowhere for the Pressure to go once the pump puts the the pressure in the rail right? (also have an AFPR) Its still doesnt seem to make sense to run a return line. (If the answer is out there, I cant find it.)

You don't, however, need an AFPR if you have an FMU. You should convert to a return-type fuel system if you'll be using either an AFPR or FMU, though.

[Peej420a]

Originally Posted by VelocitàPaola

Yes, you need both, not one or the other.


You don't, however, need an AFPR if you have an FMU. You should convert to a return-type fuel system if you'll be using either an AFPR or FMU, though.

Ok, LAST question about this: Is the breather line that goes to the charcoal canister on the fuel pump housing ok/Safe to use for the FMU return on the 97' Or do I need the 95' Fuel pump housing (is there a difference?) I have them both, but i cant seem to find the 95' Pump housing. I had 2 95' models and a 97'. Just a Little FYI (I Wrecked the first 95'(Still have it), Junked the second and driving the 97').