Hi Michael We did both, just swapped the injector connectors and left the ecu pins alone and the problem moves to where ever the number 6 wire is connected. All the coilpack connectors were brand new so there isn't any corrosion We have been waiting for the same thing, to eventually fix it and have it be some thing stupidly obvious Thanks for the suggestions
Hey syntax_x Yep all the injectors have a common earths We have checked the resistance between the ecu plug and the signal wire for each injector and had them all come out the same :-/ When we had the noid light hooked up we tried to notice a difference in the brightness but it was so hard to tell with the naked eye! Cheers Simon
Hey tektrader We think so we were pretty careful when putting it back on after the lifter change. The car pulls pretty hard once you start moving. We may end up pulling it apart again just to check though if this keeps up Hasn't been reporting any error codes. We thought we might have stuffed up wither the set sensor or o2 sensor wires with VTC connector but double checked the wire colours matched up, so they should be good. Thanks for the suggestion re fuel pressure, we hadn't done that yet Cheers Simon
Hey guys, Thanks for the suggestions about checking the battery and alternator. I was actually having dinner with a couple of the guys tonight and they suggested that perhaps it was my battery and alternator not quite up to task. One suggested that the amperage that the alternator puts out at idle is relatively low and that could be causing the drop in voltage which might cause the slight misfire. He said once you're doing 1500-2000 rpm driving the amperage increases to 40-50amps which might be why the misfire disappears once driving. I hope this is the stupidly obvious thing that we amazingly haven't tested yet!! :rofl:
Thanks for everyone's suggestions tonight! It's great to be able to bounce ideas off of the collective Z brains!! I'm going to have an agonising wait for a couple days until I can get home and check the battery and alternator! I'll keep everyone posted. I hope it's this simple!!! :zlove:
Silly question, but how does one go about testing the alternator? Just check the voltage at the battery with the car running?
Puzzled....... If you have a dodgey alternator, how does that manage to just provoke a misfire on No.6 cylinder
Missed the point.... I was referring to the voltages you mentioned in your tests. If there were voltages at 11.3 & 11.8VDC at the test points while the engine was running there is a major problem. I would think those measurements were taken with the engine off. Those voltages indicate the battery as being flat. There is half a volt difference in those measurements, I'm asking why? They should be the same across the board. How good is the multimeter you're using? Once again I would suggest performing a voltage drop test. You mentioned changing lifters, they weren't used lifters were they? To check an alternator, measure the voltage across the battery terminals & also check the AC ripple voltage & amperage at the alternator output terminal [not at the battery].
Hey East Coast Z, Correct those voltages were taken with the engine off. Leaving the probe on the injector signal wire for a few seconds the Voltage would fluctuate from 11.3 to 11.8V up and down. All of them had the same fluctuation and between the same range. I think the battery is definitely on it's last legs, so i'll look at sourcing a new one ASAP. The multimeter was good, actually we tried a second just in case and found the same results. The lifters were all brand new. Thanks for the how to :zlove: Cheers, Simon
Hey zx299, I'm hoping that if the alternator isn't up to scratch then perhaps #6 has either a weak spark at idle or the injector isn't opening correctly? I'm a bit out of my depth when it comes to the electrical side of things I'm happy even if it just rules another thing out Cheers Simon
We checked the voltage at the battery this morning and with the engine idling we got a steady 13.9V so it appears the alternator is charging the battery. We also put another battery in to see if it made any difference but there was no change. Had a quick look at the fuses in the engine bay and they were all fine. We've started to run out of ideas. We are considering pulling the plenum and replacing the larger injectors with stock injectors and going back to a standard tune. Just to see if that makes any difference. The thing that makes me doubt it will do anything is that it was fine with the larger injectors when we did the lifter change, and we can move the issue by swapping the injector connectors :-\ but we are running out of things to try. Cheers, Simon
Hi guys, Still haven't had any luck trying to track down this slight misfire issue. We had the plenum off and replaced the injectors with known working stock injectors, replaced the ECU with one with a tune for stock injectors (hitec). Also had the engine out to fix a cracked turbo oil line and confirmed that the timing belt was on properly. The problem still moves between cylinders 5 and 6 if I swap the signal wire over at the ECU. So to me that suggests it's the wire in the loom. I have gotten some ECU pins so am going to make my own cable to test. I have a spare injector connector that I will run the wires from. The signal (white/blue) wire that runs directly from the connector to the ECU is easy, but the common wire according to the workshop wiring diagram runs to a fuseable link. How can I "mock" that up? Is it safe to run it to the positive battery terminal for testing? Or should I be buying an inline fuse to be safe? Cheers, Simon
