[Dan T]

This has happened 3 or 4 times now. I go to start my 83 Spider after it has been sitting a day or two, and when I crank it over it backfires and blows the hose loose on the intake manifold. The car doesn't backfire when running, and not always when starting either. Just sometimes, and it seems to have something to do with sitting for a while.

Dan

 

[ghnl]

Do you touch the gas pedal when cranking? You shouldn't have to. Check for intake air/vacuum hose leaks & check the Throttle Position Switch (one of its positions is to tell the computer the throttle is at idle).

 

[jc96]

I touched on this on another thread and am also looking for thoughts. My 164 w/Twin Spark 2l pops thru the intake on cold starts sometimes. Part of my "new to me ritual" invovlves cleaning the engine and everything else under the hood. So, I popped of the oil vapor seperator and blew it out and cleaned out all the hoses. Next cold start no backfire. Not sure if I disturbed something or if the cleaning did "something". Subsequent starts w/no backfire as well. I'm thinking maybe I shifted a vacuum hose in some manner as I note the main big bore hose has a wear spot in it that might be allowing added air into the system. Just food for thought. My experience with a PCV system which is what I equate this seperator thing with is limited but I don't recall it causing much more than ruff idle @ times. Thoughts gang? Chris

 

[Dan T]

I have found the car starts better if I depress the gas petal just a bit, not pumping it, but just pushing down on it slightly. I know with fuel injection this shouldn't be the procedure, but it does seem to help...

I will check the throttle position switch and recheck vacuum lines.

Dan