Saturday, January 01, 2011 - 10:24 pm, by: Jacob Thomas(Jacob_t)
Hey guys, i've been getting some pretty average fuel consumption so i tried replacing the spark plugs with NGK BKR6E-11 V-Power. I found that under light acceleration at 2000RPM the revs would start to go down not up. If i pressed the accelerator in further boost would start to build, the revs would then slowly climb to around 2500 and then the car would instantly surge forward with acceleration. I thought that it could be due to the wrong spark plug gap so i pulled them all out. They appeared to be gapped to 1mm so i regapped to 0.8mm. The problem is now even worse. Medium acceleration is alright but as soon as i get to 60km/h and 2000rpm the revs die and the car starts to slow and begin to backfire. The only way i can drive the car is by constantly slowing down and the accelerating back up to 60. If i try to accelerate when the revs are dropping or its backfiring it only makes it worse, i have to take my foot completely off and then pulse the accelerator until i can get the car to rev back up again.
Sunday, January 02, 2011 - 06:57 am, by: Daniel Clarke(Dieseltrain)
Check all connections on coil packs . Also check you put the coil packs back on and also the Ignition leads on properly too . Also check your Air flow meter , might need cleaning .
When installing the plugs , did you overtighten any and perhaps cracked a plug ?
Sunday, January 02, 2011 - 09:47 am, by: Jacob Thomas(Jacob_t)
I'm pretty confident that its not the afm. I know david grab so i'll see if i can borrow his and see if it makes any difference.
I made sure i didn't over tighten any of the plugs and they all looked pretty clean after 460kms. I'll also see if i can find the plugs i removed and see if it makes a difference.
Monday, January 03, 2011 - 12:23 am, by: Aaron deVisser(Bigdiv)
Im having exactly the same problem, except i've put in the champion platinums. Mine at say 20-30% throttle will not go past 2000rpm unless i open the throttle right up. Didn't do this straight after i put the plugs in, probably took 3 weeks after i did the plugs for it to develop the same problems
Thursday, January 06, 2011 - 11:00 am, by: Daniel Clarke(Dieseltrain)
Should be running gaps of no more than 0.8mm , can try gapping them down to 0.7mm and see how it goes .
Sounds like Your coils or plug leads are playing up . VVTI's run wasted spark , 3 coils with twin outputs . 3 Are coil on plug and 3 ignitin leads . Sounds like the leads need replacing .
Wednesday, February 16, 2011 - 04:01 pm, by: Jacob Thomas(Jacob_t)
Just for clarification sake, i took the car in last monday after i got back from japan and it turns out that it might not have been spark plug related at all.
When driving to the mechanics, as the car warmed up the symptoms appeared to become less apparent and almost non existent by the time i got there. They put the car on the dyno and under cruise the afr's were 16.5 - 17 WTF!!!! they disconnected the O2 sensor and AFR's dropped back to normal. I drove it home, no issues with surging/backfiring. I put in my old toyota O2 sensor and the car now drives like a dream
So possible causes of the problem were: 1- the spark plugs has some kind of coating which after a little bit of driving wore/burnt off. 2- the hiflow O2 sensor •••• it self at the same time i put my new spark plugs in. 3- combination of poor spark and high AFR's caused surging/popping.
Previous
