Car pops and bangs in overun

[PhilNW 44]

Sorry to hear this, back to the basics then,

 

is it specific to an individual cylinder or a general misfire?

 

Has the popping and banging on overrun disappeared?

[Gavin Waddell 18]

The misfire isn't asot bad as before , and the pop and banging is still there just a lot less know,changing the afm cleared it up a bit, I'm going to change the coil next to see if that makes a difference. One part at a time.

 

I can't really pull the plugs off as its a bit intermittent, it doesn't do it at stand still more under load.

[Richard309Sri XU5JA 205GTi 8]

if AFM ok for sure, back to checking the dynamic timing? using a strobe light.

 

worth doing before changing the coil ?  as the spark could be ok/could be adjusted to ok?                                               

 

I know you can just do it by ear by rotating cap by hand as said many times on the forum though but

I was looking at the timing "window"  and I can see the marks fairly easily - not impossible to see the timing plate and the flywheel.  

 

And the valve clearances to check like Cameron said

 

(in your old AFM is the flap 100% free?  I just found out that using an old/exchange AFM on mine the flap stuck open, and therefore flooded the engine=black soot started from exhaust. thought I broke something really serious but the flap was stuck. just interested to know also if they have that fault commonly, as it sounds like there was a fault on your old one) 

[PhilNW 44]

On 8/24/2021 at 8:09 AM, Gavin Waddell said:

The misfire isn't asot bad as before , and the pop and banging is still there just a lot less know,changing the afm cleared it up a bit, I'm going to change the coil next to see if that makes a difference. One part at a time.

 

I can't really pull the plugs off as its a bit intermittent, it doesn't do it at stand still more under load.

I think I would be inclined to put the original AFM back on as it gives the biggest response to the problem. The replacement AFM , while it seems it has improved something, could mask the basic original problem

 

Solve/change one thing at a time

 

Something changed between the drive to work and the return

Edited August 25, 2021 by PhilNW

[Gavin Waddell 18]

I see hear what your saying Phil, before i had my non start problems last  year the car always ran fine, whilst looking for the fault i did the old retrack AFM mod so maybe i did do a good as a job as i thought.

 

The AFM that i put on was a non molested one from a that a  guy had in storage for about 10 years, he was a parts hoarder.

 

I changed the coil over on Tuesday drove the car yesterday and today and it didn't play up one bit. Im going to see what happens over the next few days. I also put in some of shells finest 95 as i had been putting in cheap petrol in before.

 

We will see what happens, for the time being im happy to be driving it.

 

Gavin 

[camgti 56]

Clearances. Just do it. Its not that hard. Measuring them is super easy and will tell you right away if theres an issue. It will usually be worse when the car gets to temp or is in traffic as the tolerances tighten up even more. 

[camgti 56]

Did you measure these yet? Im keen to know if thats the issue. 

[Gavin Waddell 18]

I haven't measured them yet as the car has been running fine since changing the coil. Will check them this winter when i take her off the road.