Sluggish v6 holden

[Esky_addict]

Right! back on track after my wee debacle in general talk. I have a surf with a 3.8 in it was running like shite so I swapped out the alternator that fixed it mostly (actually runs allright now). 

However its gotta bit of a stumble just off idle like when im taking off which is a right c*%t in a manual, and when the foots down it a bit sluggish. Being a 3.8 in it I imagine it should go like a cut cat.

Also I notice that when the electric fan is on it the miss is more obvious so I just leave it off.

[0fnsiv]

check the voltage at the ecu.......use the power and earth closest to the main ecu plug..... if you dont have 13.5+ volts it could be the problem.....

[Esky_addict]

Im a bit retarded with this new fangeld early 90s technology. Is ecu the box that normally resides in the passenger footwell?

[CaMpylobacter]

check all your earths and connections. if it's been used for some reasonably serious 4wding flick the lid off the ecu and make sure it hasn't been used as a makeshift fishtank/mudhole. 

[Esky_addict]

So what your saying ofinsiv is find the main power supply for this, and check the voltage using the closest earth.

[0fnsiv]

yep....first check the voltage across the battery itself to get your 'benchmark'...... check the ecu earth is clean and the voltage doesnt fluctuate to much while its running....use the fans and headlight highbeam to see if the voltage drops.....make sure there is good earths (note multiple) on the engine block to the chassis(preferably direct to the battery pole).... If the battery is 'in the boot' it may pay to run a negative lead direct to the bell housing.....

[Esky_addict]

Oh yeah i had like 14 volts at the ecu. Miss has dissapeared maybe stale fuel? Still feels kinda down on power but runs faiely smooth if that makes sense. Will invest in some plugs and leads when the wallet allows

[Esky_addict]

So yesterday when I left work I put my foot down in the surf skidded up through first hit second and it kept on pulling so while cold it goes apeshit. After a couple minutes running its back to running like a 2.8.

[chris r]

Sounds like it could be water temp sensor

[Esky_addict]

Theres a wee push button switch understeering wheel which has a light in it. I think the light is hooked up to the check engine light. It flashes none stop and ive read that it could be ecu on way out will swap that out tonight

[HighLUX]

Is it an auto ecu running a manual trans now?

[Esky_addict]

Not to sure aye i brought it converted. Any way to tell?

[Esky_addict]

Also just noticed a black box under passenger carpet about 100mm square with a green led in the middle. Anybody know what that will be?

[Esky_addict]

done a bit more digging, has same switch\diagnostic light as found on marks4wd.com. the fan came on when diagnostic light was pressed as part of it going into diagnostic mode. Next question is has anybody done of know of anyone that's done a conversion with a www.marks4wd.com kit.

Im not sure if the fans are supposed to come on automatically or if they need a switch.

[Jase]

VN Computer V6 Fault Codes

V6

Code 12 - System Pass (OK)

Code 13 - Oxygen Sensor (O2)

Code 14 - Coolant temperature Sensor - Voltage Too Low

Code 15 - Coolant temperature Sensor - Voltage Too High

Code 16 - Coolant Temperature Sensor - Voltage Unstable

Code 17 - PCM Coolant Temperature Circuit

Code 19 - Throttle Position Sensor

Code 21 - Throttle Position Sensor (TPS) - Voltage Too High

Code 22 - Throttle Position Sensor (TPS) - Voltage Too Low

Code 23 - Mass Air Temp Sensor (MAT) - Voltage Too High

Code 24 - Vehicle Speed Sensor (VSS)

Code 25 - Mass Air Temp Sensor (MAT) Sensor or Circuit - Voltage Too Low

Code 26 - Mass Air Temp Sensor (MAT) Sensor or Circuit - Voltage Unstable

Code 28 - Transmission Problem

Code 31 - Theft Deterrent System - Missing Signal

Code 32 - Manifold Airflow (MAF) Sensor or Circuit

Code 33 - Manifold Absolute Pressure Sensor (MAP) - Voltage Too High

Code 34 - Manifold Absolute Pressure Sensor (MAP) - Voltage Too Low

Code 35 - Idle Speed Error

Code 36 - Vacuum Leak

Code 41 - Crank Angle Sensor

Code 42 - Electronic Spark Timing Circuit (EST)

Code 43 - Knock Sensor Circuit

Code 44 - Oxygen Sensor Lean (O2)

Code 45 - Oxygen Sensor Rich (O2)

Code 51 - Memcal Unit - Check for bent pins

Code 52 - CALPAK Unit - Check for bent pins

Code 53 - System Over-Voltage - Alternator produced > 17.1 Volts for more than 2 seconds

Code 55 - ECM - Check ECM Grounds or excessive input voltage

so the light should flash for 1 sec for the tens then a 2 sec gap then at 1 sec intervals for 1's,

ie a twelve would be one flash 2 sec gap 2 flashes, then say a 53 would be 5 flashes a 2 sec gap then 3 flashes.

the diagnostic will spit all the logged fault codes at you so you may get a few numbers written down stop writing once you're back to the first code you wrote.

just on a side note pull the plug from your coil pack and check the female ports all grip a pin firmly, pretty common for these to loosen if the loom is pulled tight on them, also take your coilpacks off and have a good visual inspection of them as they often crack underneath giving you a short

[Esky_addict]

Yeah getting no codes only 12, even when regulator failed and was overcharging. I will pull coils and check underneath them.

One has a crack down one side i noticed. Is there anyway to check a coil?.

Trucks running good as when cold but almost has a slight hint of a bog down under acell when warm.

Still havent done plugs and leads yet.

[Jase]

put a set of coilpacks on it then , if its visible cracked an leaking its guts out it will short and miss,

I always found the series 2 coilpacks were better not the boxy square series 1 ones

[Esky_addict]

will do yeah its got s2 coils on it at moment. Its starting to do my head in flat battery before work this morning only just put alternator back in yesterday after having it checked and new brushes put in. Spat out a code 41 CAS after a jump start.

[adio]

I had the same symptoms in my old commodore vn 3.8 series 2. Would run fine cold, as soon as heated up was missing and generally ran like rubbish. 

 

Turned out to be a crank angle sensor, I also go that fault code. You can test if take vehicle for a drive let it warm up to get the symptoms. Park up and slowly pour cool water over the sensor, located behind the harmonic balancer. Then start up again see if it runs better, something to do with the sensor expanding when getting hot giving wrong readings.

 

I replaced with a second hand one the first time, a year later same symptoms again. So I went new the 2nd time around. From memory wasnt that expensive new. The hardest bit was needing the correct tool to remove the harmonic balancer / pulley. Hence why the first time I went 2nd hand from a local wrecker in chch and they replaced for me took no more than 10 min for him with the tool needed.

 

Another way to test is - From memory when you check the fault codes / jumping the pins the radiator fan goes full speed? I had to do that a few times to get back home as the radiator fan going for 5mins or so was enough to cool the sensor down and get you home ! 

[Esky_addict]

Sweet adio thats exactly what i wanted to know. The fault code light is shown through a button on my surf. When you push the button it brings up the codes, the fan also goes when button is pushed so must be cas