C5 Diag

mazzerman

no....not even an attempt, just cranking.

C5 Diag

saplumr

mazzerman

yeah pretty sure it went out but will double check when i put the battery back in. and check for tach movement as well.
went underneath just now to check the crank sensor connector next to starter just to make sure it was secure.
I can check crank and cam RPM at the same time on the T2.
just printed out all the service manual connector end views for all the ign coils, crank and cam as well so at least i know which wires are ground, low ref, IC control and IGN voltage.
I just checked my test light and its toast so i.ll pop out in the morning to get a new one, (i need one really as it's the easiest and quickest way to check for voltage.

mazzerman

No never.... it's always been stock, the only mod is the hotwire kit, but while i'm testing i've reverted back to the normal fuel pump wiring (OEM)
until i sort the problem.

saplumr

mazzerman

Yes it had the dark burn marks on the side, it has been replaced now, the forum opinion on this is that the connectors underneath the fuses/relays become loose and make intermittent connection, i have had it apart and pushed all the connections back up and used hot glue to hold them in place, because when you push the block connectors back on and tighten up the bolts between the fuses/relays, it can push the connectors back down again, so hopefully my little DIY effort kept them in place.

C5 Diag

mazzerman

OK, put battery back on, security light goes out after a few seconds.
turn motor over but NO tach movement on the dash. so i guess its cam or crank sensor???

C5 Diag

mazzerman

ok so far, i had to drop the cat to be able to get to the CRK sensor, nearly had to take the starter off as well, its really difficult to get your hand behind the starter and solenoid but eventually got the connector off so could start back probing, my battery has had a bit of a bashing again being in KOEO for so long so it was reading 12.5v when i started to back probe, 12v reference wire was reading 11.7 which i believe is low, i think it should be no more than 0.5v difference to the system voltage.
I ran out of daylight so will have to continue tomorrow.
I'm not sure whats next but i think i'v got to test for a short to ground on the 12v reference circuit?

C5 Diag

NOOOOO !!...you didn't have to back probe the crank signal wire at the sensor itself...too hard with the starter in the way !!...like I had said in my post you can back probe the signal wire at the PCM instead (see pic)...right front tire removed and remove the plastic access panel....back of the wheel well. I think it's better we check for injector pulse...I included a video by "The Master" and you can see we check for feed power (pink wire on mine...the feed wires are all the same color on all injectors).Turn key on and with 12 volt test light connected to ground or battery negative test light should illuminate...if not check injector fuses... one for each bank...if 12 volt feed good now connect the 12 volt test light to battery POSITIVE... if you can back probe connector (pushing t-pin in back of connector...(pic enclosed) you won't risk spreading the pin if you front probe... if you do front probe just DON'T shove the end of test light into the pin !!….now crank the engine with test light to other wire (usually different colored striped wires)...test light should flash...it might be difficult to see in bright sun...watch the video !!...I think we should do this before messing around with the crank sensor....and if no injector pulse we can look to bad crank sensor but we HAVE to check wiring integrity first. Oh, 11.7 is most likely OK...your system voltage might be a little low with KOEO for a while...the .5 volt difference you were thinking of is the "voltage drop" voltage on a "loaded" circuit...a running fuel pump for instance... you would check with a voltmeter the difference between positive battery voltage of the battery and the power wire at the fuel pump !!...difference should not exceed .5 volts. Same for the ground side !! ...I also included a video of circuit test of 3 wire Hall Effect crank sensor...don't remember if my signal wire was a pull up or down...the signal on mine was dark blue and white wire !!

mazzerman

cool, i will try that tomorrow, its the spark at the plugs that is bothering me.
i somehow need to check the crank wiring for short or open, before i pull the trigger on a new crank sensor.

C5 Diag

Let's look for injector power and control first then concentrate on crank sensor and it's wiring...I included another great 2 part video on crank sensor operation and testing....my crank wiring is dark blue/white- signal input, yellow/black- low reference (ground), and light green- 12 volt reference (feed),
If we have no injector pulse then definitely look at the crank sensor !!….and if you have to change it....DO NOT INSTALL AN AFTERMARKET ONE...i.e. Dorman etc...OEM only !!...also, let's address that priming fuel pressure too !!

mazzerman

videos are great and very informative, will definitely start with the injectors and at least eliminate them from diagnosis,

C5 Diag

DEFINEITELY !!!....did you ever check that buzzing with that test light or a DVOM instead of the Power Probe ??...wondering what that was about and if that's still an issue ???

mazzerman

i got hold of a test light and got no light on those fuses with key off, which was buzzing with probe. so not sure what that was about......

C5 Diag

Great !!...Time for a new Power Probe....LOL !!!...get the 4 !!...AWESOME tool !!

mazzerman

thats really cool kit.....i would buy it just for that fuel injector feature, that looks so easy to use compared with setting up the scope.