rb25 problem no power ?? im lost Please help

[matafied]

Well I have been going nuts for a week now trying to figure out what happened to my cars power so any info could help. The car the motor and Trans was in was in an accident so the plan was to transplant the goods to a different s13 I acquired. So all was good and the motor was running awesome like it always has. The car sat for about a month and a half until I was able to pull the motor out. When I did I had some broken studs and a cracked exhaust manni. No big deal I ordered all new studs and replaced the manni. Ok so back on track motor was installed and all seemed to be good. I drove the car for about 4 days and car ran fine but just didn’t have the power that it had in the other car. I thought it was just the bad gas, so I drove all that gas out then filled it up with fresh gas, did help but no cigar. Me and my brother went 2 wide and he raped me!! I mean it was bad so now I know something can’t be right hmm idk!well I had Friday off and thought I would just spend the day fabing up exhaust and fmic kit, got it done at 3 in the morn and was giving it hell all the way home just to hear the new exhaust and at about 5800 waaaaaaaa bluuuuuuuh I let off the gas because it felt like I just blew off a ic hose so I putt home and figure I will just fix it in the morn. Cause it was late. the next morn I can’t find nothing wrong with the ic piping so now I am worried, now the car doesn’t even feel half as good as it did and I am completely lost. I figured my fuel pump went out from sitting so I changed it from my other car. That didn’t help! So I looped out my fmic kit and just ran it looped to rule out boost leak and it helped, it just still didn’t feel right and it wouldn’t rev past 5800 in 3erd gear!! ahh so I’m getting frustrated! Well I thought maybe the voltage to the pump might not be enough so I tested it and it was showing 10.8 volts at idle, so ok I might be on to something so I ran wires strait from bat to the trunk just for trouble shooting and now have solid 12 v at fuel pump. Now for the drive! Didn’t help!! when sitting you can rev and it seems fine builds boost and sounds perfect, but when you drive and its under a load no dice! I am so lost, anybody have any ideas????

Oh and last question, what is the purple plug in the pick for?? ( I know the other one is iac )


Modified by matafied at 8:44 AM 3/24/2008

[S14-NEO]

the purple plug is for the FICD for A/C idle ramp...i stil think you have issues with your MAF..check it with a known good one...have you checked that yet?

[matafied]

i havent checked that yet, i just figured it was ok because it was reading airflow with safc2 and seem two be correct

[S14-NEO]

see the thng is the mass air flow meter has a volktage reading but it also has a volume reading..if the volume reading is off the ECU wont add the proper amount of fuel thus alot less power...

[matafied]

10-4 i will swap it out in about 20 min to check it

[silviasgp06]

ok i was thinking, we both have SAFC's. from what i gather the safc manual says the in/out settings depend on the characteristics of the MAF, I have mine set to 2 in 2 out, what about you?

does anyone know if the different in out settings matter if its the same in as out?ex: 02 in 02 out, 05 in 05 out

______edit, just called apexi and they are saying it 04 in 04 outgoing to see if it makes a difference now
Modified by silviasgp06 at 3:52 PM 3/24/2008

[matafied]

well i have mine set to 02-02, i changed my maf and i looped my pipe and nothing, then i changed my fuel filter and put on a after market fpr set my fuel presure to 40 psi and valah she pulled like old times, man and did it feel goooood lol

so i put all my junk back on and hooked up my fmic and its having trouble idleing now so i think i have a small boost leak or something idk

[silviasgp06]

in/out number made a little difference, but still weird feel past 5k, and i notice there was a cloud of smoke one time, but i didnt do it after that.

why 40 psi, do you think it was running rich at higher rpms?i need a wideband soon.

[S14-NEO]

omg...you put this engine in another car and didnt replace the fuel filter????take away 10 RB points away from you...hehe

[240z4u]

Sounds like you may have split a vac. line or hose under the intake manifold. Slight leak at idle, but big leak under boost! I had a similar problem as you and that was the case.

Build a boost leak tester and you will find it.

Evan

[matafied]

sounds like a plan, i am just glad im running rich now lol i may have missed a weld on my ic piping so boost check it is

[matafied]

well i had a tear in one of my couplings, fine at idle, opened under boost. so i will give an update

[rb25drag]

Isn't the little things a killa?

It really sounds like a boost leak. Do you not have a boost gauge hooked up?

[matafied]

yea that did it, good to go now! so it turned out to be two problems, Low fuel presure and a small boost leak! seems fine now. quick question for those of you running safc2, fmic and 3 inch exhaust on stock turbo what % do you read on 7psi at redline?? for some reason it seems to be reading higher since i made the piping kit for my front mount. it only ever read 98% on a cold night with 10psi of boost, now it's reading 98% on 7psi. Is it reading higher #'s because of the much better piping now?? more volume to fill? idk

[l0nestar]

I was wondering from the beginning why you did not build a 'leak tester' and pressure test your system. I believe Fiznat made an article about it and spent a whopping $12.

Anyways. Glad it is working for you. I was thinking of asking what everyone has their AFC's set to - currently mine is 0:0 or 1:1 - just using it for the quad digital gages

[matafied]

because im freakin hard headed ! this is the only problem ive ever had from this motor lol oh and it didnt fix it haha turned out that my maf is bad so good call S14- NEO