engine behaving wierd

[Skar]

ok here is the case, m20b23 l-jet. at times when idling the is a lot of vibrations, the exhuast node doesnt sound clean (as if misfiring). when accelerating the revs climb to about 3.5k to 4k then there is a sudden drop (loss of power), its goes down to about 500 rpm and the engine dies. the car had been lying under a tree for about 3 years and now it has been rebuilt to running condition but its not running well.

1. initially the fuel pump was faulty (lots of whinning noise), therefore it was changed

2. vacuum hoses and radiator hoses all changed

3. any idea what it could be??

4. could it be the, AFM, Ignition cables, ECU, distributor, fuel pressure regulator?

thanks

[Dan318-is]

never ever heard anything like that

you need help from the pros of here for this one

[Martinaston]

Could be a worn distributor (bearings, contacts, arm)
Or the timing could be out, The jetronic has an rotation adjustment at the bottom of the distributor, but don't try that without a timing gun on an old engine or you'll be taking it to the scrap yard.
Let a garage check it, (then you can blame them )

[Skar]

thanks for the replies, hmmm this time i am taking it to the garage, like you guys said if they screw it up, i can blame them, well they said it could be the airflow or the ecu, will only know what it is tomorrow

thanks