hi guys, My n/a has had weird problems for aaages. it guzzles way too much petrol and the gearbox "PWR" mode cuts in and out intermittently. when the PWR mode is working properly the car feels a lot more responsive and doesnt smell like its running rich. but then it will cut out and the idle usually get rough and when i accellerate the car just bogs down and isnt responsive? it might just be a loose wire but i wouldnt know which one it could be? i replaced the TPS and its still doing it. i might not have adjusted it properly though. any ideas vl geniuses?

try replacing coolant temp sensor (new one), o2 sensor, and afm and see what happens. With the PWR, just check the wiring and plugs aroun the shifter, auto comp and on the gearbox itself.

O2 sensor mate

i adjusted the afm and replaced the coolant sensor connection and the car seems much better. the afm was a long way out. i'll see how it goes on the petrol now! thanks guys!

someone else also suggested the thermostat could be too low so the engine never fully warms up - this makes the CTS tell the computer its still cold and this means the ECU will overfuel and keep doing it, So suggest two things if you still have the problem:- Update thermostat or check Coolant Temperature Sensor (CTS) ie. Its possible the thermostats might open too much or stay open too long when engine cold in winter, seems plausible but havent checked it yet, I would be inclined to mod the CTS though if I was sure it was the ECU overfueling because of cold engine etc Quote: Originally Posted by timmo i adjusted the afm and replaced the coolant sensor connection and the car seems much better. the afm was a long way out. i'll see how it goes on the petrol now! thanks guys! What does this mean "... afm was a long way out..." precisely and how did you check it ?

i see! i might swap over my thermostat then. i just checked the resistance between the outer most pins on the afm. they were somethings like 1200 ohms so i adjusted them to 382. i checked the fault codes on the ecu and it was giving me code 21 so i cleaned the connection and swapped the coil. the fault went away and the car is running a bit better now. the car was using a tank of petrol for less than 200km before that so im hoping its improved. pretty sure it has. but still any suggestions would be cool cause its still not getting great milage?

Many things can be the cause of various problems in VL's. The only way to know which item or sensor is the problem is to change one by one or better still, if you are going to keep the car for a long period of time, and it has been ages since certain items were replaced, then maybe its time to replace them. Change each item then go driving and check it out. Could be; Dizzy Cap, CAS, Air Flow Meter, Temperature Sensor, Oxygen Sensor, Dizzy Rotor Button inside Dizzy, Fuel Pump, Leads, etc. Do a service and change oil and filters eg Air, Fuel, Oil then slowly change the other items. Even if you have a mate which you can borrow from his VL to check certain items like the AFM etc. Here are some settings for the AFM that I have learnt over the years...FYI Pins 2 & 6 (Ignition on but engine off) - 3.6 volts Pins 2 & 3 (Engine running at idle and normal operating temp) - 2.2 volts ** Reducing Voltage Increases Richness **

cool thanks man! i'll adjust my afm to those settings tomorrow and see how it goes. i have a spare engine that was running well before it was removed so i'll swap some more of its sensors over one by one.

The only way to be sure is to get a proper tune with an AFR meter where the cal screw on the AFM is adjusted for the tune, the 382 figure is a bit of a misnomer, many AFM's come from factory with approx that figure after their local tests - that doesnt mean its the correct figure for the VL, these AFMs are used on so many cars. Note: The cal screw does not change the AFM output - it only sends a voltage to the ECU to adjust the state of tune - mainly co compensate for the widest variable which is the fuel pressure regulator variation. Sadly the narrow band sensor in VL's is inadequate and an upgrade to a wide band with low band simulation output is a very good upgrade for cruise economy tuning edit: So we will be watching with interest as to what figures you get, you can go about 4 turns more lean on a n/a without any real problem in cool weather Some original photos have not been recovered yet.

oh ok! well its a turbo now so i had better not have it running lean anymore if it was running lean before. what would you recommend i set it to?

Those settings I supplied were for my VL Turbo. Best things to do is to take a measurement of the voltage before you adjust anything. Then adjust the AFM to my settings and take the car for a drive and see if you can notice anything. If you dont notice anything in particular, then maybe try leaving it to the new settings and check your consumption. Either way, If you give a turbo car a bootfull every now and then, always be on the safe side and listen for detonation. Bad fuel can cause this amongst many other things. Let us know how you go.

My fuel consumption is lots better now! it was the coil that was the problem. its got a turbo now but im still running the NA intake manifold (turbo computer/injectors). what do i do with the vacuum lines on the manifold? im pretty sure that im not getting any boost because its all escaping through the vacuum lines? it feels like it will spool up to about 0 pressure and then will just run ****house. bit confused!