Interpreting data. VS s3 Log

[MAGP]

Might be best to tune the petrol then too save the motor?

I'd leave the LPG system disconnected altogether until the petrol system is tuned properly. Tuning the LPG to make it run correctly right now may be masking the problem and will probably add confusion later.

Back to basics.
Whyzee could you please post up a list of everything you have changed and how many of each thing have you tried?
Have you back traced the wiring to make sure all the wiring is good?
Is the battery in good condition?
Is the alternator functioning properly?
Are all the earths grounding properly?
Do you have a workshop manual with a diagnosis guide?

The symptoms you describe point to airflow measurement but the wiring, alternator, battery can all have an effect on the signal to the ECU so these things need to be confirmed as working and in good order.

Are you able to revert back to a bog stock tune with only VATS disabled?

[delcowizzid]

Is the dizzy in the right place so number one matches up with the cam sensor phasing

[Whyzee]

This is my problem, it's a standard engine (with crane 268) so similar in specs to the 195i engine. I don't *think* it's a tune issue - I don't want to mess with the petrol tune because the factory tune should be a good base tune? I could have the tune altered but I think that would be covering up the real issue

with the MAF unplugged and ignition on, testing with the multimeter I found differing voltages. 12v from the pink wire, black/red to earth and the other one (can't remember the colour) tests at 5v. I'll check these against the factory specs when I get home.

Delcowizzid, what do you mean about the cam sensor phasing? I just fitted the dizzy with the rotor pointing to no.1, so maybe I've done it wrong.

Magp, I'll get a list sorted once I'm home and post it up. Done pretty much everything I can think of. Even tried 2 different ecu's/memcals and run a separate +12v feed to the positive side of the injectors lol

Again thanks for the help

[Dylan]

Given its a small cam I can't be sure how well the MAF is calibrated from GM. If there's any incorrect data from factory for any reason then the new cam wont help. If they are calibrated fine a change like that shouldn't effcect it.

[MAGP]

This is my problem, it's a standard engine (with crane 268) so similar in specs to the 195i engine. I don't *think* it's a tune issue - I don't want to mess with the petrol tune because the factory tune should be a good base tune? I could have the tune altered but I think that would be covering up the real issue

Where did you get this tune?

The dizzy fits the same as the old non-sequential dizzy. The cam sensor phasing is the location of the cam sensor within the dizzy so the ECU knows when the engine is at TDC number 1. If the dizzy is set to fire cylinder number 1 at the correct time the cam phase will also be correct unless the chopper wheel or sensor are broken. Is your base timing set to 10 degrees BTDC?

You did block the MAP sensor vacuum source didn't you?
What have you done with the evaporative fuel connection on the engine?
Anything that has a vacuum connection or a connection to an external source (e.g. evaporative fuel canister) or is an outlet for intake or crankcase air (e.g. dipstick, crankcase breathers) is a potential source of unmetered airflow.

[Whyzee]

Might be best to tune the petrol then too save the motor?

I'd leave the LPG system disconnected altogether until the petrol system is tuned properly. Tuning the LPG to make it run correctly right now may be masking the problem and will probably add confusion later.
Whyzee could you please post up a list of everything you have changed and how many of each thing have you tried?
Have you back traced the wiring to make sure all the wiring is good?
Is the battery in good condition?
Is the alternator functioning properly?
Are all the earths grounding properly?
Do you have a workshop manual with a diagnosis guide?

Okay, will leave the lpg disconnected until it's sorted - only did that so that I could get to and from work.

So far I have done/replaced:
-ignition module
-coil
-checked timing 3 times (in diagnostic mode)
-removed exhaust (initially suspected a melted cat or blockage)
-replaced MAF sensor 5 times (got a couple of cars here with an ecotec and l67 plus some spares)
-added an extra earth from battery to body and from body to block
-replaced spark plugs, leads and distributor cap/rotor (even though they were only 2 months old)
-replaced injectors with reconditioned and flow tested bosch injectors (P/N 0 280 150 973)
-Replaced fuel pump with a GOSS unit & ryco fuel filter
-Fuel pressure reg
-compression test showed that all cylinders had similar cranking pressure
-alternator was replaced about a month ago with another bosch unit (charges at 13.8v or so) and the battery was replaced at the same time.
-disconnected purge solenoid and reconnected the old vacuum type valve for testing
-Swapped o2 sensors from side to side after I realised the VS only uses 1 sensor (genuine bosch units - 6 months old).

I'm sure it's not a mechanical problem as it was running fine with the old '424 ecu and MAP setup. The only reason I made the change is because I needed sequential injection to run the LPG vapour injection. I'm sure I've changed more but that's all I can think of off the top of my head

This is my problem, it's a standard engine (with crane 268) so similar in specs to the 195i engine. I don't *think* it's a tune issue - I don't want to mess with the petrol tune because the factory tune should be a good base tune? I could have the tune altered but I think that would be covering up the real issue

Where did you get this tune?

Is your base timing set to 10 degrees BTDC?

You did block the MAP sensor vacuum source didn't you?
What have you done with the evaporative fuel connection on the engine?
Anything that has a vacuum connection or a connection to an external source (e.g. evaporative fuel canister) or is an outlet for intake or crankcase air (e.g. dipstick, crankcase breathers) is a potential source of unmetered airflow.

I got this memcal from a guy who had it in his VS with 195 roller engine before it was written off - so I am a little skeptical, but this is the second memcal which shows the same symptoms. I'll change the memcal with another one I got my hands on which I know for sure has the factory vs tune. Yes the timing is set at 10 deg btdc in diagnostic mode.

The MAP sensor vac port is being used for the lpg MAP sensor now. I'm using the purge solenoid and is connected as per the factory diagrams. The PCV system also unmodified. I'll check again for vac leaks again tomorrow. The symptoms are typical of a massive vacuum leak though

I have the ALDL cable so can post screenshots or logs if that would help my case at all

[yoda69]

You need to be running a V8 MAF sensor from a VT 5.0 litre or vs series 3 5.0 litre, the V6 MAF sensor is different as are ls1 maf sensors.

[MAGP]

-replaced MAF sensor 5 times (got a couple of cars here with an ecotec and l67 plus some spares)

You need to be running a V8 MAF sensor from a VT 5.0 litre or vs series 3 5.0 litre, the V6 MAF sensor is different as are ls1 maf sensors.

Which takes us back to

have you made sure the MAF is calibrated correctly?

[Whyzee]

I have 2 'vt 304' MAF sensors here that I've also tried - I'll check the part no's to see what they're really from. I called a couple of parts stores before I tried different MAF's who said that the vs v6 and vt v8 MAF had the same part numbers, but I wouldn't be surprised if their systems are wrong.

[MAGP]

Just did a search and this page says the MAFs are the same on V6 and V8.

Are there any markings, part numbers on this memcal? Are you able to identify it using the Memcal ID Tool?