VS V6 Engine Problems

[Rusty's VS]

Hi guys,

I have recently been expriencing some problems with my commodores engine management system. The car is a VS SII Manual V6 S pack with 168 000Km on the clock. Mods include sports exhaust, cold air induction, finer filter panel filter, ported airflow meter, and powerchip 98 octane memcal.

My problem started a few weeks ago when the engine would just die for no reason, and wouldn't restart until you turn the ignition off for a second or so. I did the self diagnostic test and came up with code 46 and 49. I then when trough the test in the workshop manual and found the DFI module fualty. All was good, then about a week later it stopped agian. But would restart striaght away without going to ignition off. Check the ECU agian and no fualts were present. Did think much of it until two days ago when I gave it a bootfull and it started to miss really bad. I got home and reved it up under no load and the miss was gone. Checked to computer again and code 49 was listed. I thought mabe the Crank angle sensor was faulty and I have changed that today. Got the car back together and took it for a drive. Still missing badly. Turned around came home and checked the ECU again. Code 47 and 49. So I checked all earthing points and cleaned a tightened them. Also tried to clear the codes but the would not go away. (had the engine fuse out for 5min) I accendently started the engine with the paperclip still in the diagnostic plug. I turned it off and started again and when for a drive. Engine didn't miss at all. Got home again and check ecu an code 47 and 49 remain. What is going on with this thing?? :b: Has anyone got any ideas?? Is the ECU on its way out??

Sorry to go on and on, just thought I should give as much info as possible.

Cheers

Rusty

 

[kopper69]

DFI module, crank angle sensor and ecu are tied up together so it can sometimes to be difficult to fault find the system. I would always start with the crank angle sensor, as its a fairly common thing. DFI module seems to be more reliable, make sure the connectors on tight. ECU is usually pretty good, expensive as hell if you need to replace. Fault codes. Well I would disconnect the battery for a few mins. There shouldnt be any reason why the codes stay in there. Starting the car with the paperclip in is not a big deal. Make sure that the spark plug leads are nice and tight. If you replaced the module the leads might not be sitting nicely. Make sure they are tight on the spark plug side as well. If you have a multimeter you can check the resistance of the leads fairly quickly. If you pulled the leads off (when you removed the dfi module) by the lead itself and not the boot of the lead, you may have damaged the lead thus causing a miss. If the car is running good now i would say the crank angle sensor was the problem all along. To remove the codes disconnect the battery for 10 mins and see what happens.

 

[Rusty's VS]

Thanks,

I haven't checked the plug lead resistances. They are all on tight though I've checked that a few times now. I don't think I have busted a lead as I always pull them off from the metal boot not the lead. Ok I'll try disconnecting the battery to clear the codes. It kind of threw me when I first drove it with the new crank angle sensor as it still missed. Only did it under load though it was fine when in neutral. I would have thought the sensor would work striaght away??

 

[maginoodle]

Mine worked fine with no load then would miss under load. I put new plugs and leads on and that fixed it.

 

[Rusty's VS]

Mine worked fine with no load then would miss under load. I put new plugs and leads on and that fixed it.

Did you get any fualt codes?? I put new plug in it a week ago. Maybe I do need new leads as well. I'll see how it goes tomorrow.

 

[maginoodle]

No fault codes mate i just tried the usual suspects first.

 

[Rusty's VS]

Well it seems the crank angle sensor change rectified the engine codes. (had to disconnect the battery to clear the codes) However it was still missing due to a loose coil pack. When I changed the DFI module I must not have done the bolts up tight enough and one of them came loose alowing the coil pack to move around. I re torqued the bolts and it runs sweet as.

Thanks for help guys

cheers

Rusty

 

[CHANDLC]

Mine had the same prop it went on for 2 years and after changing leads, plugs, DFI, Crank sensor and coils and 40000klm after i decided to change the spark plugs again for one last atempt and it worked and haven't had a prop scince and the only difference with the plugs is that i went from nkg to bocsh super 4.