Backfiring Issue In Built R33

[Shayde]

This is ossie_21 logged in under Shayde's username btw

95 r33 with lots o shite, wolf ecu has recently been rebuilt with all forged internals and tuned to run 14 or 20psi.

At the moment under low and heavy loads i'm getting consistant backfiring at similar intervals in each gear all the time. 1st gear at some point I havent seen yet cos i never stretch 1st, but 2nd at about 55kph, 3rd at 80kph, 4th at 100kph & 5th at 140kph. Under acceleration the car will hit these points & backfire harshly on me, if I keep my foot down the car will finally struggle past it & boost on as normal. When no acceleration at all and the car is slowing down the car will again hit these speeds, not backfire because there is no acceleration but the revs die right down, but ONLY at these speeds. Doubt its a rev issue because they are different, in between 3100 & 3500 approx.

Apart from these things the car sounds & drives as normal, I can get around the backfiring but that will mean minimal boost, pretty ghey in a near 400rwhp car

That "was" it, but now a couple of other things have showed up. the other day I started the car as normal, got to the servo & filled up. Went in & payed, got back and the car wouldnt fire up straight away. It now does this all the time, taking quite a while to start & generally being a bitch. idle is now quite rough, with a decent amount of black smoke under minimal revs. i may or may not have a cat, but still more black smoke than normal/there should be.

Also, the keyless entry now decides not to work after not being activated for a while (ie overnight). the way I started it up this afternoon was by opening the door & getting the alarm, then putting the key in the ignition and turning it to on & then pressing it. so its gone from a maybe plug/coil issue to possibly being ecu related.

I had my car for 1 day in Perth after the retune & it was perfect, but since I got to queensland its been like this since i picked it up from the TNT depot a week ago.

If anyone at all can help out with this it would be great, all i can narrow it down to is plugs, coils or an ecu issue, ive gone over as many hoses i can find but only checking connections & not leaks. have to do that in the light after reading through some threads but Im hoping for some feedback asap because i need to get down to the gold coast to see my brother & nephew tomorrow or Friday, so the sooner the better! plan b is getting down to the area & getting to a respectable qld workshop to see what they can tell from seeing the car, so if any qld based people can help out there for tomorrow that would be sweet. Cheers, Nathan

[R31Nismoid]

First of all, i would get the alarm looked at.

Once that is sorted, then move onto the running problems which could be coil packs, dirty connections, fuel pump... there is a long list

Best to get rid of the alarm/keyless issue first IMO.

[mass_iv]

yeh id get the alarm checked out once iv checked all fuses first... if the problem is still there id go on and check plugs, leads and coil packs at the same time, sounds like a dodgy ignition problem.. i wouldnt check out the ecu till last, as its not common for it to be ecu related, then again i know nothing about the wolf ecu, so dont quote me on that..

[Shayde]

Update.

I (Shayde) was driving behind Ossie just to check how much smoke we're getting here. Basically under load I can't see the back of his car. Under light load, taking off, shifting into 2nd and then 3rd in low speed there was very noticable smoke.

One other thing he told me was that he was driving in 14psi setting and his boost guage read 18psi and his 20psi setting reached 19psi and then cut out. He described it as the engine dying. The car slowed down and just lost all boost and such.

His tuner has thinks it's most likely the map sensor line. Possibly a leak or something like that causing this. If this isn't the case it could be something more sinister.

I want to check all the standard ignition fault causes as well.

Thanks for your help so far guys, it's much appreciated.

- Shayde