missing under power, popping on deceleration

[drewe]

Hey all,

New engine is in fine (though I think the gearbox is leaking oil!! Well, something is, but not much so anywho...)

IT idles wonderfully - if not a little fast.

Under power though, it misfires a lot. And when you are out of the throttle letting it slow in gear, it does a coco-pops imitation all the way down (snap, crackle, pop)

Also, patheitic when cold - again, idles fine, but stutters under power real bad (I just warm it for the moment)

Any idea's? Sparkies are new, leads are good, coil is almost new.....

And since it runs under idle, I am guessing not electrical to the injectors or anything?

Last thing - I changed the throttle body over from the old motor - do you need to gasket seal it? Maybe I am getting air in the join?

Thanks again guys.

The car has one month to behave. 2 weeks of me trying, 2 weeks to the mechanic. If still not right, selling for whatever I get, despite it owing me $10K from the past 6 months!

[murcod]

The gasket should be fine, I've had my TB off and just reused it.

If your leads are new (could pay to double check them anyway), what about the distributor cap? Have you got your old engine- try swapping the distributor out of it perhaps and check the ignition timing.

Was the timing belt changed?

I get some popping and carrying on at partial / closed throttle going downhill.

Idle speed is adjusted on the top of the throttle body - do it once up to temp - the screw is under a rubber cap. Clockwise to slow the revs.

[drewe]

Thats the funny thing that makes me think I have a leak.... Screw is down tight ....

Did a gasket goo job on the throttle body, a *little* better, but still must be air getting in somewhere.....

[murcod]

Check all the hoses hanging off the manifold to see if any are leaking. Also take the rubber inlet hose off the TB and check the large oval air bypass inlet (just in front of the throttle butterfly inside the TB casting) - there should be no air flowing throw it when the engine is up to normal temp and idling. Just try blocking it with your finger.

If you've got power steering there are hoses running to the pump to check from the manifold; also the PCV crankcase hoses could also cause issues (as could the charcoal canister etc etc.) Many things could be causing such issues.

Also check the accelerator cable is adjusted correctly (check butterfly is closed completely when TB inlet hose is off.)

Make sure you've got the headlights, heater fan and aircon off as these will all open valves that will increase the idle speed!