Hi all, Ive a problem with a VS , and ive tried all sorts of things to get rid of the problem. Its best described as a jerk/jolt, very similar to how the car feels when pulling a trailer...or...kinda similar to a car thats had its timing too far advanced. Ive changed the CAS, the Mass air flow unit, the ECU, IAC, TPS plugs (ngk) leads (bosch) and got a substitute coil pack to try. I have since put the car on LPG, and no different.
The problem is more noticable when the torque converter lock is engaged at about 60k/h in 3rd gear. I go on a flat road, up hill, the problem exists. When i slow to under 60k , the torque lock releases and i assume the torque coverter cusions the engine miss. If in 3rd gear at about 80k/h, the problem isnt as evident. Could it be the o2 sensors?? i havent tried unplugging and driving. Can I test them easily? I have ECU codes saying O2 sensor rich, inbalance of fuel/air mix between r and l manifolds and also a code which says injector fuel voltage varies, which may be caused by the lpg getting a feed off that curcuit...Any help really appreciated.
An imbalance in 02 sensor readings aye. I'd be putting your information together. 1st you've got 02 imbalance, 2nd you've got injector problems. Check resistance of injectors with a multimeter. If no major variance then you'll need to perform an injector leak down test, a fuel pressure guage is needed. The rich 02 sensor code tends to lead me away from an exhaust manifold leak as it would NORMALLY read lean. Hope this helps
The injector codes are due to a bad (non genuine) lpg install, no need to be checking anything.
The misfire sounds like a tracking or cracked spark plug, take them all out & check for cracks & any tracking marks, it will look like thin black almost burnt looking lines along the ceramic part of the plug, if any have these marks replace them & the lead for this cylinder as well as it will be damaged
Well Demenace did say he had replaced both leads and plugs not to mention coil packs but no DFI module, but maybe on installation he did damage porcelin body??
try testing the injectors. with an imbalance l to r theres a prob with just one or two which gives a small jerk on dead strokes. and the o2 backs this up saying ot oh bad burning in the engine dude. so i'd try that. if not read codes again as you may get an ecu prob somewhere along the line
G'day all..thankyou for your replies, appreciated. The car is now running on LPG and its running no better than when it was on petrol. I have changed the leads and plugs...and got a DFI and coils to try...but no difference at all. If something was faulty and i replaced it...even with another faulty part, then id hope to get a different pattern to the fault. Even if soemthing changed slighty, id know where to look more. Ive not tried unplugging the o2 sensors and seeing how the car goes without them. Ive heard when the torque clutch solenoid is activated, the ECU changes the timing and fuel to economy more...true?? if so...cld it be an O2 sensor giving false readings to the ecu?? rgds...