Need Help

[_Sawyer_]

I just put a rebuilt rb25 moter in my car and I dont know why or what im missing but i cant get the injectors to fire up. Ive checked the pulse at the ecu and its there, the coil packs are firing because if i drop fuel in the throttle body the motor will fire for a second or two, the fuel pumps working etc etc. is it possible i havent pluged something in? i obviously have the injector loom on the intake manifold pluged in but ya. any help would be great.

cheers, Paul

[_Sawyer_]

Anyone?

[FJdat]

maybe u have mixed up the inlet/ outlet on the fuel lines...try swapping them and see if it starts

[_Sawyer_]

maybe u have mixed up the inlet/ outlet on the fuel lines...try swapping them and see if it starts

good suggestion because thats what i origionally thought but theres no pulse at the injectors anyway to let fuel in

[mattymagoo22]

you need to check for compression, spark and fuel. Your engine should have compression it just got built, when cranking have you got fuel pressure, if yes are your injectors pulsing you can check them using a noide light or if you don't have that use the red flashing LED from your alarm cut it off so you can solder it up again later!!! but first.

to check for spark remove the intake pipe and the valley cover undo a coil, stick a screwdriver into the bottom where the spark plug would sit then rest it on the rocker cover with only the handle touching the rocker cover but also that a spark will jump from the metal shaft of the screwdriver to a metal part of the engine..... OR jsut hold onto to it.... just kidding this will hurt but you'll know its got spark. so if its got spark back to the LED.

Strip the insulation back and wrap the bare wire around some pins or paper clips, now you should back probe the back of the injector plug so you don't open up the connection at the plug and cause a bad contact, but assuming you haven't done this before carefully place wire in each connection inside the plug now get some one to crank the engine and it should flash the LED if it doesn't then you have problems. if it does the last thing i can think of would be cam timing.

Hope this helps

Cheers Matt.

P.s you don't have a kill switch do you.

[TurboX]

How long have those injectors been unused!?

This was a problem I had with injectors that had been spray tested etc and sat around for 3 months till I installed them.

Ended up taking them off and getting cleaned again after banging the hell out of them with a screwdriver and hammer and getting a couple to fire before working out they needed a fresh clean.

Problem fixed for free by supplier - EFI Technology who supplied the RX7 550 cc's, albeit a bit reluctantly as they said I should have known better.

But after that, put them in and no probs.

[BH_SLO32]

good suggestion because thats what i origionally thought but theres no pulse at the injectors anyway to let fuel in

No pulse? Do you have power up to the injectors? The injectors are fed by a common wire which in the case of the R33s is a grey wire. Check the plug at the front of the intake manifold. There are 2 plugs at the front of the manifold. One of the plugs has wires for the knock sensors and air regulator and the other is for the injectors, a main power feed and individual return wires from the injectors. The ECU simply earths the individual injectors as required.

Cheers

Edited February 21, 2007 by BH_SLO32

[_Sawyer_]

Thanks for the feed back.

Matt- its defiantly not a spark or timing issue because like i said if i put fuel down the throttle body, the motor will start and idle for a few seconds.

Turbox- hard to tell because measuring with the multimeter i have 5volts at the pins for the injectors at the ecu and 0 volts at the actual injectors so I would assume they work if i actually get power to them.

Bh slo32- I was thinking that 2 about the grey wire, do you know of any other connections where the grey wire might lead 2? i.e does the grey wire have a plug somewhere on the loom, something i might have missed?

Thanks again guys

[mattymagoo22]

yeah you should have battery voltage on one side of the injectors as the computer just grounds them to operate them.

I haven't played much with the wiring so sorry I can't be much more help but sounds like youre onto something with the grey wire.

Good luck

Matt.

[_Sawyer_]

I think the problem is defiantly in the grey wire. it goes to a large male connector that has eight pins and thats on the turbo side of the engine bay which i dont have anything connected to. can any1 check on there car where or what it goes to? maybe im missing something from my loom. Thanks

[BH_SLO32]

I think the problem is defiantly in the grey wire. it goes to a large male connector that has eight pins and thats on the turbo side of the engine bay which i dont have anything connected to. can any1 check on there car where or what it goes to? maybe im missing something from my loom. Thanks

Series 1 Rb25s get their power feed from the engine bay plug near the power steering reservoir (rect plug with about 6 big pins). Series 2 get their power feed from one of the body plugs inside the cabin near the ECU.

Easiest way to check is to unplug the appropriate plug at the front of the intake manifold with the grey wire and test for 12V as described in my previous post. I have attached a photo I took sometime ago of the 2 plugs. You can see the grey wire entering the top plug.

Let us know how you go.

Cheers

[_Sawyer_]

well I ended up tracing the grey wire back to the other side of the engine bay where it goes to a plug with eight pins on it. I ran a constant positive to the pin and sure enough, the motor came life! huge releaf. Id still like to know where this plug is meant to be connected but for the mean time ive soldered a wire from an ignition line to power it.

Thanks to all that helped, I'd buy ya a beer 1 day if your around lol. cheers