Now my RB20 won't start

[apex_7]

I yanked the engine and harness to paint the car and replace the clutch. I put it back in and the damn thing won't turn over. Does anyone have any wiring diagrams on the ECU wiring? Basically I've narrowed it down to my injectors not firing. I can jumper B+ and manually make them fire and the car will idle. I checked all my sensors and I'm pretty certain they're all plugged in and the ECU is reading them since I can make it run w/ gas in the intake or jumpering pulsing B+ to the injector signal. So what's the deal? Why no signal to my injectors? Any input would be great!

[JonPowell]

Wont turn over or wont fire?

One wire on the injectors is power(constant+12V) the other is ground through the ECU. Check for the power.

Also, try this.....take out the CAS and turn it by hand with the engine on, see if you can hear the injectors clicking, OR stick a long shank screwdriver on the top of the injector and your ear on the handle....see if you can hear them firing that way.

[apex_7]

The injectors just won't fire. The injectors show 12v and gnd and also show propper impedence. When I test the CAS wires at the ECU, they show voltage. When I measure for signal on crank at the injectors, I get nothing, but they still have 12v. So basically the wiring is good. I've tested that too. Any other ideas?

[JonPowell]

Check and see if the spark plugs are firing...might be bad CAS...

There are 6 wires for ground on the ECU

Cyl1=101-WhiteCyl2=105-White/GreenCyl3=103-White/RedCyl4=114-White/BlackCyl5=110-White/BlueCyl6=112--Yellow

Check those for continuity from the ECU to injector.

[BoostFab]

was the motor running before? did you check all the ground points, making sure paint isn't preventing it from making contact. it might be something simple.

[apex_7]

Yes the engine was running before. All connections are great, I'm 99% sure. The only thing I did different is relocate the battery and replace the green relays next to the ECU w/ some different ones because I lost the other ones but they are all working. I've looked at all the wiring diagrams I can find and still can't figure this out. CAS is working perfectly, shows voltage, etc. I just don't get it! It worked fine before I painted the car. I didn't have the coldstart injector hooked up until now, but that doesn't have anything to do w/ this problem. I just found that looking at the wiring diagrams for the RB harness. But I don't have any good diagrams that are detailed enough to really get in depth w/ this problem. I've taken the ECU apart and looked all through it and followed the pin numbers and can't find anything visually wrong w/ the boards. So I don't know. Someone has to have had this problem before!!!!!! HELP!!!!!!!

[JonPowell]

ARE THE SPARK PLUGS FIRING?

[apex_7]

yep. ignition system works fine. it will start for like 5 seconds w/ the cold start injector and it will start if you pour starter fluid in the intake.

[JonPowell]

Do the igniters have power to them?

[apex_7]

The ignition system works fine. It starts if you pour gas directly into the intake.

[JonPowell]

Do the igniters have power to them?

I meant injectors...

Trying to trouble shoot with you guys here instead of jumping to the hard stuff, I always like to rule out the easy cheap stuff first.....It would really suck for you guys to buy a computer and find out that the injectors had no power to begin with.

[apex_7]

yeah, they've got power and ground, just no signal. I really appriciate you taking the time to ask these questions because it is possible to overlook some of this stuff. So keep it up til you run out of ideas

[BoostFab]

yeah, they've got power and ground, just no signal. I really appriciate you taking the time to ask these questions because it is possible to overlook some of this stuff. So keep it up til you run out of ideas

i have this same problem a while back, the engine only runs when you spray starting fluid into the intake. check the red wire by the 6-wire plug, make sure the white/black wire on the rb 6-wire plug by the battery, and see if it get 12v signal. that's the wire that feed power to the injectors.
Modified by BoostsFed at 4:30 AM 11/21/2004

[lyon23]

is your fuel pump working?

[apex_7]

yes, fuel pump works.

[JonPowell]

Ok, so here is where we sit, just so I understand, I am going to number these things and I would like you to respond to each one.

1.) Spark on all 6 cylinders Y/N2.) +12V to all 6 injectors Y/N3.) Continuity between all 6 injectors and the ECU Y/N4.) Fuel pressure Y/N

5.) What exactly are you talking about when you say coldstart injector....I have worked on a few RB motors and only remember 6 fuel injectors.....one for each cylinder. I know on some VW's they had an extra injector in the intake line for cold starts, 4CYL had 5 injectors, but I dont recall one on the RB20...nor anything on the ECU for a 7th injector????

Lets get to the bottom of this problem....If you can answer yes to #'s 1-4 the injectors should be working.

[apex_7]

1) Spark on all 6 cylinders................Y2) +12V to all 6 injectors...................Y3) Continuity between all 6 injectors and the ECUI only tested two, but I would assume it would be the same for all......Y4) Fuel Pressure................................Y5) Signal from ECU............................N

So I guess it's new ECU time.

Oh and about the cold start injector thing... It's basically a signal from the car to the ECU that the car is in the START position and sends fuel through all 6 injectors to make it start when it's cold. It's not physically another injector, but that's always how I've heard it.

[JonPowell]

I would test the other six injectors, and unhook your coldstart injector. start there, if that is the only thing different from before when it ran....try it for kicks.

What sort of a signal are you looking for from the ECU? It should only pulse ground for the injectors.

[frosted flakes]

i bet its the ecu...im having same problem and IT JUST HAS TO be it...reason being is because all 6 injectors wont work...now what are the odds of that? HAS to be the ecu...not getting signal...

[apex_7]

Did a new ECU fix your problem?

[frosted flakes]

HEY I GOT IT TO WORK!!! I AM SO HAPPY BEYOND BELIEF!!!

Boostfed is right

"i have this same problem a while back, the engine only runs when you spray starting fluid into the intake. check the red wire by the red 6-wire plug, make sure the white/black wire on the rb 6-wire plug by the battery, and see if it get 12 signal. that's the wire that feed power to the injectors"

that was my problem!! and it worked!! ....the solder connection somehow broke off!

i bought a new ecu and power transistor for nothing but i am so happy it works its not even funny...!! i went 3 weeks without a car waitin on **** to get here when i could have juST FIXED IT !!

THANKYOU ALL!!

[JonPowell]

I meant injectors...

Trying to trouble shoot with you guys here instead of jumping to the hard stuff, I always like to rule out the easy cheap stuff first.....It would really suck for you guys to buy a computer and find out that the injectors had no power to begin with.

I hate to say I told you so, but I told you so......I am glad it finally got started for you though!

Get to whooping some poor ricers *** now!

[USMCgetsome]

ok i'm a little lost when you guys said red 6 pin plug by battery. are you guys refering to the plug that they grey wire in the 8step was hooked up in?

[USMCgetsome]

ok this is what i have..

12v signal to injectorspulse signal from ecu to injectorsfuel pump, pumps but i have no idea about the fuel pressure.

12v to ignitonsignal to ignitionspark to all cylinders

tried to check the red wire with red plug but can not find the plug. Starts with fluid but will not stay on. i'd like to reset the ecu because i think there's a possiblity it might be in diagnostic mode but my ecu has no led light. seems like everything is working correctly but a fuel problem exsist. i also got it started when i push started it. i'm lost??

[BoostFab]

ok this is what i have..

12v signal to injectorspulse signal from ecu to injectorsfuel pump, pumps but i have no idea about the fuel pressure.

12v to ignitonsignal to ignitionspark to all cylinders

tried to check the red wire with red plug but can not find the plug. Starts with fluid but will not stay on. i'd like to reset the ecu because i think there's a possiblity it might be in diagnostic mode but my ecu has no led light. seems like everything is working correctly but a fuel problem exsist. i also got it started when i push started it. i'm lost??

it's not the red plug...it's a typo in my post...it's the rb 6-wire plug w/ with the ka gray oval plug by the bttery.

[BoostFab]

i have this same problem a while back, the engine only runs when you spray starting fluid into the intake. check the red wire by the 6-wire plug, make sure the white/black wire on the rb 6-wire plug by the battery, and see if it get 12v signal. that's the wire that feed power to the injectors.

[USMCgetsome]

man i have no idea where you lookin.. i only see a seven pin grey. would it help if i took a pic of mine to show you? i really don't know where the grey 6 pin is.

[Bluefire]

Theres two plugs in the engine bay harness that hook up to the motor harness. They are located against the engine bay wall next to the battery. One is fat and gray, the other is small and red or brown I forget.

-Bluefire

[BoostFab]

brown.

[USMCgetsome]

found them the grey and brown plugs on mine are in the R/H whell well and feed into the fire wall. woo hoo. still haven't checked wiring at the 2 yet. i'll post findings later.