Walbro question?
- Thread starter cykornr
- Start date
You dont have to do the 12v mod. You have to do the j tube bypass because the hole is too small to relieve all the pressure from the fuel and will result in a rich running condition. Shaeff wrote a great write up in the 2nd opr 3rd page of the tech section
Oh and by the way the 12v mod helps with pump pressure drop. Do a search that reads like this "12v fuel pump" and Include the quotations
I have a write up with pictures on the install, and it links to Shaeff's thread. Mine is still on the first page about halfway down
just a real world example...
on my buddys eclipse that i've been working on for the past year, we just recently did the 12v mod to it among have a lot of wiring issues...
but with the pump on the OEM wiring, it didnt move NEARLY enough fuel, at an idle it was lean. but AFTER the 12v mod, the pump was chuggin right along and the AF at an idle is between 14-15.
so its defintaley worth it to take the time to rewire the pump, and its not that many wires anyways.
on my buddys eclipse that i've been working on for the past year, we just recently did the 12v mod to it among have a lot of wiring issues...
but with the pump on the OEM wiring, it didnt move NEARLY enough fuel, at an idle it was lean. but AFTER the 12v mod, the pump was chuggin right along and the AF at an idle is between 14-15.
so its defintaley worth it to take the time to rewire the pump, and its not that many wires anyways.
Re-wiring the fuel pump makes a HUGE difference. I wouldn't be surprised if the stock wiring is giving the pump 10-11v. Wire it off the battery with a relay, you'll be seeing 13v when running.
ForcedTorque;1034515 said:
the combination of your pictures and his write up helped me out quite a bit!
And a response to this thread:
I noticed no difference in performance. As there really shouldn't be. Unless you need LOTS of fuel all the time the there's really only one reason for this...and that's for tuning
The ECU uses a resistor pack and relay for the fuel pump. The fuel pump receives 9V (IIRC) normally and under higher demand it switches the pump over to 12V. This voltage change creates big problems for tuning since it can happen at anytime the ECU decides.
A note about my thread........There are several very valuable responses that are just as helpful as the write up. I did a few things that could have been done better. This forum is tremendous! Other members let me know what I did, and corrected me on them. Make sure you read the responses.
Rennat;1034635 said:
:rofl: On my old GSX, sitting at a stop light if I turned my turn signal on I could hear the pump whining LOUDsoftLOUDsoftLOUDsoft in tune with my turn signal.
/thread jack
Rennat;1035284 said:
personally, i barely hear my 255 walbro. my 94 blazer fuel pump is more noisy!.......then again, maybe that's why it just died yesterday..SHIT...that was my backup car :nono::3d_frown::3d_frown::nono::3d_frown:
Rennat;1034635 said:
True, but keep in mind, DSMs are known for this....
Soooo you were running lean at idle? serious issues much? lol
14.6 is fine... because were using an safc i cant just a perfect 14.6 consantly... so it wanders a little between 14 and 15...
and its been fixed now, his wideband wasnt even registering on the lean side because it was so lean when we started it with OEM wiring... but the 12v to the pump it registers 14-15..
and what exactly are dsm's known for? along with what "issues" are you talking about?
and its been fixed now, his wideband wasnt even registering on the lean side because it was so lean when we started it with OEM wiring... but the 12v to the pump it registers 14-15..
and what exactly are dsm's known for? along with what "issues" are you talking about?
SevenMKIII;1035264 said:
My idle does that lol.
I think DSMs are poster children for every automobile related problem known to man.....am I right? At least the ten or so people i know that have them have had some really weird issues, and only about 3 of them didnt know what they were doing in the first place. Mine ran alright tho, considering freshly rebuilt with a new 16g, what can go wrong?
considering i've built 3 of them now. and this one has 1g big rods, along with bc 272's, cam gears, extreme psi race intercooler kit, ceramic coated turbo, manifold, and o2, along with a full 3'' megan racing exhaust.
i have his 16g set to 20psi and it rips like a fuckin bat out of hell on fire! if it was RWD i would be scared to drive it... but its AWD, so it just sinks down and GOES! and tomorow im going to go out and fine tune it some more just for the hell of it.
with an eclipse though, 99% of the time, its the owner not performing maintence on them... my friend put in his front main seal with a screw driver, and he leaks 1 quart a week... lol.
i have his 16g set to 20psi and it rips like a fuckin bat out of hell on fire! if it was RWD i would be scared to drive it... but its AWD, so it just sinks down and GOES! and tomorow im going to go out and fine tune it some more just for the hell of it.
with an eclipse though, 99% of the time, its the owner not performing maintence on them... my friend put in his front main seal with a screw driver, and he leaks 1 quart a week... lol.
Rennat;1035427 said:
You made it sound like you were having some serious problems with the idle. I would consider starving for fuel at idle a problem. yes 14.8-15.2 at idle is fine, you were just making it sound like it was at 18 or something.
DSMs? hmm....shattered t-cases, blown synchros, overheating and running very hot, irregular cold starting (stock or not) crashing pistons, blown rings, DETO and knocking, needing to rewire walbros (everyone ive ever been around) poor water cooling abilities (not just radiator) oh yeah loss of oil pressure due to the front cover seal, a few cases of rod knock....should i stop? Im not new to dsms, i do like them, but they are "high maintenance"
Rennat;1035429 said:
Ive had my hand in about 8 different dsm engines, from stock to not. How do those 272s idle? like shit? 20psi on 16g is oook, nothing fancy there considering mine was at 15. My newly aquired 1j would eat that. From a dig even.
It doesnt matter eclipse/talon/laser, many people are shitty "tuners" as they call themselves. I do believe that also most of the time the owner is the faulty unit. But i know that even from the brand new parts i installed on a few, they still had awkward querks about them. When i got my car, someone put a napa n/a ecu in it and fried the rings. I scored on that deal though lol
with the stock 9v of power to a 255 it was... but with 12v that walbro is kickin! haha
considering two of my friends are pushing almost 400hp ish... one has a v-trim with 21psi, and my other friend has 20psi with a 16g... neither one have ANY of those problems... lol
now, i do know a few things about blown synchros due to my 2g gst. but we wont go there... haha. if you keep up on maintence, there fine, you just cant neglect them, or launch them at 5k and expect nothing to break.
considering two of my friends are pushing almost 400hp ish... one has a v-trim with 21psi, and my other friend has 20psi with a 16g... neither one have ANY of those problems... lol
now, i do know a few things about blown synchros due to my 2g gst. but we wont go there... haha. if you keep up on maintence, there fine, you just cant neglect them, or launch them at 5k and expect nothing to break.