'84 FI Backfire and running rough until car Warms up

[searya]

My 84 Pininfarina is Backfiring and running rough until it gets warm. Any ideas? I checked Fuel pressure and timing is 10 Degrees BTDC.

[searya]

Little bit more info. Once the car warms up the idle increases to about 1600. I took it back down and being warm it stayed fine at 950.

Took it for a drive runs great over 2000 rpm. Under that it is still boggy.

thanks.

[RRoller123]

Might want to try checking valve timing. Can be done visually by the marks on the valve cam wheels and main pulley.

[searya]

Thanks. I took a look and cam and crank timing marks line up just like the picture.

Let me know if there is anything else I should check.

[Spider951]

If you haven't done so already, check for air leaks, especially at connections to and from the big air intake hose. The rubber of that hose becomes brittle with age, resulting in not such a snug fit as needed (and maybe small cracks, too), especially where fitted to Air Flow Meter. Air leaks in my '81 caused backfires and rough running; I eventually replaced the big hose plus several smaller ones and their connector clamps. Relatively cheap and easy.