Missfire

[rs250nut]

Im getting a real bad missfire and its not all the time. I pretty much loose all power when it happens then when I let off the throttle its back to normal. When it mised earlier I had a friend behind in a valver and all he saw was a four foot flame and a massive puff of smoke out the exhaust. I have replaced the dissy cap and rotor arm and have also put a new tdc sensor on. I checked the plug gaps and they are all the same.

[OUTLAW]

i was experiencing the same problems, including the rattle.....huge flames out the back, then i realised that the manifold gasket was fooked, and the manifold and turbo were all loose, replaced all that,..finger crossed:sos:, should be ok..also try turning boost down, perhaps...?

[rs250nut]

Boost is only at a bar:) You have reminded me though the down pipe is leaking a bit.

[OUTLAW]

Boost is only at a bar:) You have reminded me though the down pipe is leaking a bit.
your getting me worried now mate..., if its leaking a little, it still should not be as bad as you described..?:)

[rs250nut]

your getting me worried now mate..., if its leaking a little, it still should not be as bad as you described..?:)

I doubt if the down pipe leak is the cause of the missfire to be honest.

[Scoff]

it has nothing to do with the exhaust. if it's making flames from the tailpipe then thats because you are loosing ignition, so back to basics, check for dodgy wiring to and from the AEI, check that the overboost wires are out of the way, etc.

the easiest way to check for poor wiring is to let the car idle while you carefully shake around leads like the TDC cable, the connectors to/from the AEI and so on. If there is a duff connection there then it'll make the car faulter or cut out when you shake it.

[OUTLAW]

why have overboost wires:confused:, what are they suppose to do?....do i need to conect them back up to the hose?

[Scoff]

no, you can leave them disconnected, I ment they might be hanging about touching one and other causing a missfire.

[Andrew Cooke]

Boost is only at a bar:) You have reminded me though the down pipe is leaking a bit.

overboost kicks in at about a bar, maybe that's your answer?

[rs250nut]

Ill have a look in the morning now as its a bit late to be firing the five with a side exit. I dont have a over boost switch but will check the wiring is not shorting out, cheers for the suggestions chaps:)

[Adam 005]

carb freeze maybe:agree::disagree:

[Andrew Cooke]

carb freeze maybe:agree::disagree:

no

[Matt@CodeRedMotorsports]

Mine did this....coil lead was baked.......

[rs250nut]

I wish it was carb freeze or a fubared coil lead, I hope I get to the bottom of this soon.:scratch: