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680cc injectors on stock ECU... thoughts?
Posted: Wed Feb 13, 2008 4:19 pm
by Crashsector
The EJ22T that I bought has 680cc injectors on it. The original DTEC was destroyed so I have no record of the map or anything. What are the chances of being able to run the car on the stock ECU with these injectors, just to get it up to TurboXS to have the DTEC installed and tuned? I was planning on starting it and watching the fuel trim. If it pegs out on idle I'll just have it towed. But should I even try starting it?
I also have a JECS MAF... would it be best to use this or use the stock MAF?
Any thoughts appreciated...
--Andy
Posted: Wed Feb 13, 2008 4:55 pm
by Legacy777
I'd say you have a slim chance to get it to run well enough to drive it for any distance.
Posted: Wed Feb 13, 2008 5:10 pm
by dscoobydoo
If the 440's run with the stock ECU with a bit of a learn curve, and you are running 50% more, I am betting it will start and idle, but that will be about it.
Posted: Wed Feb 13, 2008 7:21 pm
by 555BCTurbo
It will run like ass...
Posted: Wed Feb 13, 2008 7:38 pm
by vrg3
Annapolis to Gaithersburg is, what, 60 miles? I know I'm in the minority, but I think you might make it.
The fuel trim will hit the rail. At that point you're looking at something like a 10:1 air/fuel ratio. That's really rich, but the car still ought to be able to limp with that AFR.
It might do better with the JECS MAF sensor; it'll throw a trouble code 49 but it might run better overall.
I'd stay off of boost (maybe even wire the wastegate open just in case), but I think you could get the car to TurboXS. Maybe go at night when you can more safely go slow on the beltway and 270.
Posted: Wed Feb 13, 2008 11:54 pm
by Crashsector
Thanks V. I'm probably just going to pay $40 and get a 4-wheel trailer from U-Haul and tow it up. I was just worried that with injectors that big it wouldn't even start. But if you guys think it will that makes me a lot happier.
Pushing/pulling a car, wrecked or not, onto one of those things is NO fun at all.
--Andy
Posted: Thu Feb 14, 2008 2:47 am
by 555BCTurbo
Crashsector wrote:
Pushing/pulling a car, wrecked or not, onto one of those things is NO fun at all.
--Andy
If you have a Harbor Freight there locally...they usually have comealongs for like $10
Posted: Thu Feb 14, 2008 3:11 am
by douglas vincent
You are going to want to use the JECS MAF if you are using those 680cc injectors. The stock metal MAF maxes out FAST. You need to ground the blue wire (I think and I will check my setup) and then the JECS will work without throwing a code.
The Jecs flow more air before maxing out.
Posted: Thu Feb 14, 2008 3:24 am
by vrg3
Yes, you ground the blue wire if you want to prevent it from throwing the trouble code.
Posted: Thu Feb 14, 2008 11:02 pm
by Arctic Assassian
where do you get this jecs maf from?
Posted: Thu Feb 14, 2008 11:11 pm
by vrg3
Almost any North American Impreza or Legacy from 91 through 98ish, except for turbos and 90-91 manuals.
Posted: Thu Feb 14, 2008 11:42 pm
by douglas vincent
You can also modify the JECS by filling the exterior with epoxy, the milling out the interior. Then it will flow up to 30 psi out of a GT30 and then it will max out.
When you get the MAF, you will understand what I am saying.
Posted: Mon Feb 25, 2008 2:22 am
by Crashsector
Well it started today, finally. After realizing I had the fuel supply/return lines mixed up, doh. Got a CEL though, and it could be any number of things especially with the DTEC install, but it may very well be the "blue wire" mod. Didn't have time to check the trouble code.
VIDEO:
http://www.youtube.com/watch?v=0RHuhE9oeNY
It started to run out of gas towards the end. Have to connect my laptop up and check the fuel trims tomorrow. Needless to say I'm pretty excited at this point.
--Andy
Posted: Mon Feb 25, 2008 3:51 am
by vrg3
It's definitely the "blue wire" thing. Code 49.
At least.
If it runs enough to limp to Gaithersburg, though, who cares?
Posted: Sat Mar 01, 2008 4:23 am
by Boostedballs
vrg3 wrote:Almost any North American Impreza or Legacy from 91 through 98ish, except for turbos and 90-91 manuals.
are you saying that the n/a MAF flows more air than the turbo unit?
Posted: Sat Mar 01, 2008 8:40 am
by douglas vincent
We are not saying the JECS "flows" more air. We are saying the JECS allows more flow before the MAF hits 5 volts. And if you modify it like I did, you need to flow about 30psi out of a BAT (big ass turbo) to hit 5 volts.
Posted: Sat Mar 01, 2008 8:42 am
by douglas vincent
And actually, the Metal maf allows more actual flow (uninterrupted) than the plastic JECS. Its just that the sensor itself on the metal MAF sucks.
Posted: Sat Mar 01, 2008 8:42 am
by douglas vincent
And actually, the Metal maf allows more actual flow (uninterrupted) than the plastic JECS. Its just that the sensor itself on the metal MAF sucks.
Posted: Sat Mar 01, 2008 8:45 am
by douglas vincent
Before
After
milling out
After filling in with goo

Posted: Sat Mar 01, 2008 8:55 am
by Adam West
Thanks Doug, I understand the milling but not the goo. Didn't you have another thread on this mod? Can you post the link?
Posted: Sat Mar 01, 2008 8:57 am
by Adam West
And I suppose greater minds than me have thought about swapping JEC sensor into the Metal one??
Posted: Sat Mar 01, 2008 8:42 pm
by douglas vincent
The red goo is to prevent the pressure from blowing the lid off the MAF sensor. The "lid" being the protective cover on the outside. I blew mine off on the first one I used.
Posted: Sat Mar 01, 2008 8:50 pm
by Adam West
Ah, I see, stick the sensor down since you've undercut it's base. Make sense now.
You've got a pm.
Posted: Sun Mar 02, 2008 8:42 am
by 93forestpearl
Just remember, if you misfire from being over-rich, you will cause damage to the coilpack in short order. If its $40 for a trailer to haul it, go that route.
Posted: Wed Mar 05, 2008 2:49 am
by dzx
Do you know how much it leans out compared to the stock hitachi maf Doug?