RB25 started up for the first time today :] but...........

[silviasgp06]

RB25 started up for the first time today :] but it would only run on starter fluid. seems, the ecu is slightly not working, the one i received didnt look physically in good condition to begin with, and now it seems to be the issue. Tested various components with a meter and found:

Theres Spark,Theres Fuel Pressure,but NO injector pulse.----edit----i want to add, that i havnt extended the wires for the O2 sensor cause i wanted to see if the motor would start, from what i think the 02 sensor shouldnt keep it from starting, should it?

so assuming that the ecu is the issue i need a S2 RB25det ecu ASAP, email me so we can discuss 2day shipping and such. or send me messenger on AIM(after you send an email).

my email is [email protected] AIM screenname is lessthanthree87
Modified by silviasgp06 at 11:50 PM 2/25/2008

[Shocker]

sounds like gray wire to me!

In your wiring harness for the injectors theres a gray wire which is 12v power, then the rest that are all grounds. The gray needs to be getting 12v's if its not theres your problem, check to see if it is, if not hardwire it into a 12v source I did my battery and she fired right up.

[Darius]

Sorry to steer towards the gray wire and not specifically your problem silvia, but should the 12V be fused for a certain current draw or is it okay to run it off of battery power. I had it that way temporarily, but want something more permanent. Electrical experts?

[Shocker]

Sorry to steer towards the gray wire and not specifically your problem silvia, but should the 12V be fused for a certain current draw or is it okay to run it off of battery power. I had it that way temporarily, but want something more permanent. Electrical experts?

I left it off the main 12v terminal for a year with no issues. Its now wired into my mircotech so its like factory again. It only gives the signal on start up, after that the injectors just pulse ground.

[silviasgp06]

shocker: awesome i will check today.

Darius: Yess it might a good idea be fused but to prevent possible electrical short/fire while your car is just sitting there, jump it to 12v power source that comes on when you turn the key. Im going to look at what relay kicks on the accessories, and hook it to that. But if the ecu doesnt complete the ground circuit to the injectors anyway this may not be needed, (can any one confirm this) im tired so i may not be thinking clearly.

also i have a quick question, on s13_240_rb20 post on the simular issue, people keep saying that the when you turn the CAS that it causes the Injectors to click, isnt the click your hearing coming from the coils as you turn the CAS?
Modified by silviasgp06 at 8:22 AM 2/26/2008

[d356bud]

You ALWAYS want your component fused to prevent a short that can cause your wire to heat up and catch on fire. never ever tie something to a high amperage source without a fuse.
Modified by d356bud at 7:52 PM 2/26/2008

[mott6904]

I agree with everyone check for power at your injectors. On a rb20 it gets power throught the eccs relay. I would think it would be the same on a 25 but not sure. You can find a factory service manual at skylineking.com for your wiring diagrams.

[silviasgp06]

ok when i go back i will check for voltage. I know how to check for voltage but ( shocker ) where is this gray wire that i need to energize if it is the case, the car is at my friends house so i cant go physically look at it right now.

[Shocker]

ok when i go back i will check for voltage. I know how to check for voltage but ( shocker ) where is this gray wire that i need to energize if it is the case, the car is at my friends house so i cant go physically look at it right now.

Its in the injector harness. Making sure your testing the injector side of it, and not the main harness that connects to it.

[silviasgp06]

hmm well theres 12 on the gray wire.

I pulled the CAS off and spun it while the key was in the on position. As soon as I started to turn it you here the injectors click once and all six coils going off in sequence. After spining this a few time and re-installing the CAS the car runs for a few seconds depending on how long i turn the CAS.

now i left the stock s14 pump on just to get it running then after it was running replace the fuel pump with an after market unit. But the fuel feed hose seems relatively limp though i does get pressurized, far as i knew the stock fuel pump was enough to start but now it seems it is giving less fuel pressure than it did before the the KA came out. So im thinking that its not even getting enough fuel pressure to fire the injectors.

any ideas?

tonight i will check continuity between the injectors and the ecu, the CAS and the ecu and various other items. but car runs on starter fluid so wiring shouldnt be an issue.

so as of now its either the ecu, or fuel pressure

[mott6904]

how are you checking for fuel pressure. There might be pressure in the lines but not enought to run the engine. are you checking it with a gauge and do you have power at the fuel pump?

[silviasgp06]

right now nothing is being used to measure FP, but the stock KA pump was left one just for start up purposes while i wait for a new fuel pump to come in.

the stock pump is running like it should, and should be providing enough to fuel pressure to start the motor,so im guessing its the ECU.

[mott6904]

Did you replace the fuel filter? I Would go the parts store and see if they have a pressure gauge you can borrow to make sure you are getting enough to start. Have you checked your timing belt to see if it is on correct or a compression test. If you really do have spark and fuel then thats all that left. What do the plugs look like are they new?

[silviasgp06]

mott6904: in the original post, i said it starts fine and runs fine on starter fluid. so its definitely a fuel issue. whether its the ecu injector signal or low fuel pressure im not sure but im not getting an injector signal.

To all:ok someone needs has to know what these symptoms mean because its seems pretty isolated.

real important to all:

1.when i pull the Crank angle sensor you here the injectors click(only once) while at the same time the fuel pump turns on.

2.You here the pump get quieter as you spin the CAS(as if relieving load on the pump, as if the injetors are spraying)

3.after i stop spinning the CAS the pump turns off.

4.And after reinstalling the CAS and attempting to start the motor, the motor will run >>>>Proportionally<<<< to how long i spun the CAS. So fuel is building up ontop of the valves or in the open cylinders while i spin the CAS

5. Once all that fuel is burned it just cranks, no sputter as if not even a little fuel is being sprayed. and none can be smelt,(no exhaust hooked up)

so it seems as if the injectors are operating or at least not malfunctioning when the key is in the on position and not trying to start. but when a start is attempted no fuel is sprayed.

correct me if im wrong but if the fuel pressure was low the injectors still open and the motor would still sputter a little.

next time i go to the car i will see if there really is a pulse when i spin the CAS. but im checking pulse by using a fluke set on the DC frequency analyzer and ome change, and a few other settings, which i though would show even a slight change if the injectors were firing. cause someone did say that a meter can not read the fast injector pulse but this sound wrong to me.

sorry for the long post but that everything i have noticed so far.

Camin, Carl, any ideas?


Modified by silviasgp06 at 10:06 PM 2/28/2008

[mott6904]

You might want to double check to see if you have all ofcorrect power and ground signals at each pin of the ecu.

[silviasgp06]

triple checked

[turboant]

also could be you cas is broken and not send a pulse to the injecters...... i had the same problem

[mott6904]

Checked to see if the cas key is broken on the exhaust cam. There should be a half moon in the center of the cam. There has been some problems with that before.

[silviasgp06]

key not broken but

not sure if the CAS would be broken or not, it sends the signal for the coils to fire so i figured it was that

[mott6904]

If both of the keys are not broken and the cas turned normal and was working by hand then that isnt your problem.

[Darius]

Let me get this straight. The fuel pump is priming the line, but does not continue to run after the engine is started?

The KA pump should work well enough to idle the motor. A Geo Metro pump could idle an engine. It sounds to me that either the line is plugged and the pump cannot overcome the additional frictional losses induced by the engine actually running or the pump is losing power because of incorrect wiring or relay issues.

Your CAS sounds to be working properly, so forget about that for now.

[silviasgp06]

the pump does continue to run while cranking, but injectors dont seem to be

i hooked the fuel pump directly to 12v just to make sure it wasnt shutting off while cranking.

when the CAS is spun by hand it makes the injectors click only once, should they click in sequence?

[Shocker]

the pump does continue to run while cranking, but injectors dont seem to be

i hooked the fuel pump directly to 12v just to make sure it wasnt shutting off while cranking.

when the CAS is spun by hand it makes the injectors click only once, should they click in sequence?

they should click over and over and over and over again. not just once.

[silviasgp06]

thats what i thought.

i have power at the injectors and the wires all go where their supposed to go, so at this point i think(and hope) its the ECU. one should be here weds, if not thurs.