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alan_1984 02-10-12 16:40

Before you replace your c.a.s read this
HI everyone after having starting problems with my vl i came across many articles regarding the replacment of the CAS which would be causing my vl to start only sometimes. after i had purchaced a brand new CAS i was sure i would not have problems till after the first run i had the same problem. What the! On further investigation and many and i mean Many hours going over every inch of the electrical system i had FOUND the problem many vl owners are having, which is not the CAS but a simple EFI RELAY which is locatated on the body behind the battery. after replacing this relay i have never replaced a CAS and never had any starting problems. if anyone wants anymore info or pics please reply as im happy to help.

Stu165 06-10-12 10:37

What is that relay supposed to do exactly?

5spdvl 06-10-12 12:38

More info please. Which relay, according to the wiring diagrams, are you referring to?

alan_1984 17-10-12 06:24


Originally Posted by Petros (Post 2967325)
Is this the reverse polarity dooby ?

Yes the reverse polarity relay located behind the battery

wlk21 17-10-12 10:11

i maintain more vls have cas problems then reverse polarity dooby failure..

Duke57TT 17-10-12 12:37

I hate dooby failure.

alan_1984 25-10-12 06:11

I to belived it may have been the cas but on further inspection it was my reverse polarity relay which then inturn caused my coil to *** up hence why so many cas fail. its cheap to repair and stops alot of hassle further on down the track.

Driftvh 29-10-12 01:37

I too can vouch for this!

I was having a lot of intermittent problems earlier in the year with my vl. The car would be fine for a few days and then stall and not start for 5mins to an hour. One day it would not restart so I replaced the ecu and cas (twice) and also suspected the fuel pump to be faulty as it wouldn't prime when it stopped. These had no effect and i had to pull out the service manuals. The reverse polarity relay supplies 12v to the injectors and this in turn supplies the signal via the ecu to the fuel pump.

Checked mine and it had corroded inside. Since replacing, my car has driven to and completed a skid pan day (500km round trip) and few long spirited drives without a hiccup.

Big Lee 18-11-12 10:15

This thread could be a lot more helpful with pics and detailed instructions on how to fix/avoid the problem.

gold-vlt 20-11-12 08:35

yeah can we get pics please. i think i may have this problem. have had it since i bought the car so someones probably ****ed with it.

Antho 02-12-12 15:25

Pics of the dooby?

Fresh_VL 12-12-12 09:54

great informative thread here...
So from what i gather if everyone has a dooby it'll work?

Driftvh 31-01-13 18:41

the dooby is just a relay located to the left of the battery when looking at the engine bay.

Ill try and get a pic..

Fresh_VL 04-02-13 10:44

i have 3 relays on the guard to the left of the battery...

Fresh_VL 07-03-13 16:10


MizTigaVT 03-04-13 11:25

can we get pics of this this may be my problem!

Fresh_VL 16-04-13 12:19

thread = fail

45deg 10-07-13 12:30

any farther info on these relays .. my car hasn't started in about five months, ive replaced everything, loom(checked and replaced every wire), coil(power to the coil but no spark), dizzy(cai), plugs, fuses, fusebox relays, the starting system is 100%, fuel system is 100%, o2 replaced, it started out as rb30 auto stock berlina, is currently rb30det, manual, just fitted the cooler. it was running after turbo went on and after manual convertion. its bloody killing me. anyway i'll try anything.. one relay is the neural stafty switch which i have bypassed the purple wire(last year before the manual went in. so the other two relays????? im on the edge of going back to the v8's they work better more relaible..

45deg 10-07-13 12:46

thank you admin disregard my other comments. Just a bad year. Cheers dan

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