I have a very standard vl non turbo. Shes my daily driver and tonight i was driving home from work and stoped at the lights and started to run rough in a regular pattern. it seems to surge on low revs at 60 but if you make the motor work harder its fine. ive replaced both fuel pumps, and injectors, afm, co2 when i bought the car nearly a year ago. its been fine until tonight just want to know what your thoughts are. thanks

have same problem in my calais anyone know what it could be?

Is it full on missing on 1 cylinder or just running rough, as in a bit shaky? If it's just running rough at idle probably means it's running lean. If its pretty rough then its probably at like 17 or 18:1 AFR. At stoich (14.7:1) rb30s run fine even though they will normally idle better when its rich. Ive noticed that even at close to 10:1 (very rich) my rb30 will still idle perfectly, really smooth etc. They are tuned really rich under load so thats why it runs fine when you open her up, but stumbles at low load. If it's lean at idle then it'll probably be lean at light load. Not sure theres much you can do to fix it other than getting a tune seeing as you've replaced the AFM, but you could try a new o2 sensor, seeing that thats what controls the mixture at idle and low load.

Could be as simple as fouled plugs?

chnage plugs n leads?

i have had the car for about 2weeks now and haven't had one problem until now. could it be the fuel i put in from bp because it happened after that? ---------- Post added 16-08-11 at 20:00 ---------- and one other thing when driving the car runs %110 but its when i stop at lights its idles and the stall if i don't rev?

If you don't have a wideband then when it's idling you could measure the o2 sensor voltage, i'd take a bet that it'd be zero volts which means full lean. You can't tune a car with a narrowband o2 but they are good at telling you if its rich or lean. A wideband will tell you how rich or how lean, but knowing if its rich/lean is still useful. You should check your plugs and change them if they're old looking and same for the leads. Doubt it would be the fuel. When you pull the plugs if they are all black and fouled that would indicate its rich as, which could be your fuel pressure regulator. If your tps isnt working properly then it wont idle properly because the ecu won't know the throttle's closed. I'd invest some cash in nistune, that will tell you if your tps is working and allow you to richen up the idle if it's lean, problem solved.

well i have just converted it to turbo (still in the process) but changed intake manifold with new gaskets, leads, plugs, new fuel reg, new tps, changed fuel fillter and o2 sensor lets c when i start it up hopfully in the next few days will it idle fingers crossed Some original photos have not been recovered yet.

Has anyone been using Woolworths Vortex 95? (aka E10 fuel plus 92RON or **** from a hose handle). Woollies will deny it but the proof is in the nice orange spark plugs. it can cause misfires, incorrect EGO sensing causing incorrect ECU fuelling adjustments. surging is often the EGO sensor. to troubleshoot, remove battery a lead, unplug the sensor, turn ignition on for 10 seconds, turn ignition off, reconnect battery. drive for a week and see if idle is more stable. note: Don't do this if you have high flowed injectors or anything other than stock ones, or you have increased fuel pressure as you will be running fairly rich without the EGO in these circumstances.

hey bro im new to this i was just wondering whats EGO stand for just curious because my vl manual sounds like its got the same problem and i want to test your theory to know for sure cheers

Exhaust gas oxygen sensor. note: ensure to tie up the loose wiring in the exhaust area when testing as it easily falls on the hot manifold.

just got car running still idleing like sh** but when i unplug afm it idles fine?

Quote: Originally Posted by vl_t747 [View Post] just got car running still idleing like sh** but when i unplug afm it idles fine? o2 sensor in your exhaust maybe.

changed afm today idle better but not 100% 02 sensor maybe?

Yeah you could try a new 02.