my engine as above is backfiring when you let off the throttle at speed through the tail pipe. Drives fine under load and pulls well through rev range but just backfires as above. I think i may have a gooses injector is this possible?

 

sounds like its overfueling, or is that not possible with efi? leaky injector maybe

 

Have you had the emissions checked?

 

yeh think it may be a buggered injector as the head has been changed and valves etc and it still does it. Is it possible a injector can still let fuel through when it shouldnt? Also are the blue injectors on rs turbo the same as standard efi ones from a 1.6i?

Had emmisions does at mot and passed okay

 

It is possible.

yes they are the same.

 

okay as of today im fed up. So far I have changed cam, cam followers, rockers, cylinder head, fuel injectors, checked and checked again the timing and it still does this backfire. it is also veryl tappety from topend. the only thing i have not changed is the valves themselves. I tranfered the valves from the first head into the 2nd head. Is it possible that if a valve stem itself was to be worn that it could be too much for the hydralic lifter to take up and cause this problem? Any other ides guys?

 

forgot to say although noisey it seems not to backfire when first started eg when choke is on!

 

My EFi CVH has done this since I turbocharged it. It only did it since I rebuilt it as a turbo but the entire top end is exactly as it was with the na setup. Even the injectors are the same.

I assumed it was such a "feature" of OFAC management... I'd be interested if you find a solution.

Just out of interest does your car have a flat-spot between 2-3k rpm when it was cold. Mine does and I was just wondering if it might be another symptom of the same problem...

 

hello no i have no flat spot between the revs but i would find this starnge as standard as it just does not seem right at all! Anyone else?

 

Any EFI car will have over-run fuel shut off, they have to by law to comply with emission rules.

 

have you checked your intercooler it may have a hole in it possible but doubtfull lol

 

possibly incorrect setting of tps( not seeing closed throttle)?