First - does the check engine light come on when you switch the ignition on & go out after the engine starts?
Second - does the vehicle have O2 sensors fitted?
Third - why were the coils changed, how many were changed, and did this problem occur before they were changed?

 

Miss fire, firing on 5.

Replaced all six, I had a timing chain tensioner break high up in the mountains on a friend's farm, far away from everything, she got me home and sent her to the Mac to get fixed, he told me, the coils were loosing spark in the tubes (throwing spark against the motor) engine light comes on when you tur. The key and goes off once engine is running, I replaced all 6 coils, the Mac obs gave a full service, so that is new plugs etc, it has a o2 sensor located in air filter box, something is telling me it could mayb be a tooth or 2 out of timing, I now the h20a motor, when doing the timing there is a few marks that needs to be aligned, I'm wondering whether he indeed re-did the whole timing or partial....

What you think???

Problem occurred before the were changed, vehicle has more power with new coils.

 

And just to confirm - it doesn’t do this when the engine is cold? Only after the idle drops down to the warm idle??

 

And just to confirm - it doesn’t do this when you the engine is cold? Only after the idle drops down to the warm idle??

Yes while cold, she runs better, once the ecu puts her 1000 rpm, she will start bogging, almost like she is choking, anything above 2000 rpm, she is fine!!!!

 

Lets press reset... STOP !!

did you say there was an O2 sensor in the air box..??. NO, it should not, O2 sensors only go in the exhaust system...

Coils leaking spark out the boots do not need to be replaced, the boots are a service item (like the old HT wires) and should be replaced.

If the chain broke, did the mechanic verify that there were no bent valves (this is an interference engine)..??

 

No he said nothing about bent valves 😕
If it was bent valves, surely this problem would continue right thru the revs and not idle steady.

If so this is not the case!

Regarding the o2 sensor, I was incorrect and apologize therefore, I think I was talking about the maf sensor.

The timing chain never broke, the timing chain tensioner did on the right bank

 

Good point by Aqua. And your symptoms can occur solely from an O2 sensor not doing what it should (Or being where it should be…..)

 

Thanks guys, I'm sure I don't have one, or have never seen it, where on the exhaust would it be located?

I'll have a look and get back to you all...

 

Thanks good point will give it a try and get back.

 

Hi everyone

Pulled out coupling on egr valve, doing same thing, just not has bad, also when started up the first time (cold), it only idled at 1200 rpm instead of the usual 1500, the problem was almost gone until I hit traffic, then she played up again.

Before the traffic, all I got was something that resembled a clutch shudder with a bog (like she struggling to bring revs up (duration +- 3 sec) this all between 1500 - 2000

???
Thanks

 

Just curious if what you are experiencing now is any different than when you determined a misfire on #5 and replaced your coils…..