Backfiring

[V8darren]

Hi Guy's,

Ok the old Stage 1 is really peeing me off now.

It has got a back fire out the exhaust at 3000 rpm and wont go any higher in the rev range when driving, Standing still it will rev to 5000 rpm and then misses with a back fire out of the exhaust.

I have replaced the dissi with a good one, replaced the coil, condensor, cap ect ect, rebuilt the carbs, de-choked the heads and replaced the hydrualic lifters.

Have I missed some thing or does anybody have any ideas as to what would cause this as I'm getting fed up with pulling my hair out.

Cheers for any help

Darren

[firemanshort]

I have replaced the dissi with a good one, replaced the coil, condensor, cap ect ect, rebuilt the carbs, de-choked the heads and replaced the hydrualic lifters.

I am not sure what your ETC ETC parts were but missing and backfiring under load sometimes points to bad spark plugs.

(Forgive the post if you have already replaced them.)

-Firemanshort

[Basil]

Hi did you replace the cam when you replaced the lifter's?
If not you have more than likely knackered it, made the same mistake once myself, putting new lifter's on an old cam is big no no was told this by a company who are V8 specilists.

[V8darren]

Hi did you replace the cam when you replaced the lifter's?
If not you have more than likely knackered it, made the same mistake once myself, putting new lifter's on an old cam is big no no was told this by a company who are V8 specilists.

Although it was doing it before I replaced the lifters it still has a small amount of ticking sounds. So I had thought about replacing the cam but thought I would get some opions before splashing out more cash as this fault is getting expensive now.

Cheers

Darren

P.S Yes I replaced the plugs and leads, Air filter and points

[arcticrover]

Here's another plug for summitracing.com . . . they have what I have heard to be very good Isky camshafts for a fraction of what RPi charges. The one I ordered for my rig was 60GBP. You can check it out here http://store.summitracing.com/default.a ... search.asp

[Bumpkin]

Misfire under load can be leads.
Tel

[primsil]

Have you checked for vacuum leaks. My RR was getting like that when the inlet manifold was leaking, sprayed some easy start around the manifold to find it. might pay to check all the lines connected to the manifold also, remove them and blank them off, in case the pcv or brake booster is had it.

[V8darren]

Hi Guy's

Firstly thanks for all the advice. I swaped the fuel pump over for a spare one replacing the 6 month old Facet pump, Removed the inline filter and re-checked the timing.
Hey presto, he will now rev to 6000 rpm and only then have a slight missfire. He does seem to be holding back a bit on top end acceleration but I am hoping that a tweek with the timing and carbs will now sort the final slight hickups out.

Once again Thanks

Darren