1974 1.8L engine fast idle then stalls, Fuel injection issues Options

[tshih914]

My 1.8L 914-4 with stock Bosch L?-Jetronic FI after being stored several years started to develop a hard to start problem. When finally started would stall when I give the gas pedal any input to raise the revs. I suspect there was some kind of intake air leak and while fiddling around had a backfire which blew the AF meter which I had Pelicanparts repaired. After replacing the fuel lines with the stainless ones from Tangerine Racing and flushing out the fuel system with Techron the engine started to run normally for a short time. Now the engine can be started and fast idles at 3000 rpm but again any input to rev up the engine results in stalling. The idle adjustment screw at the base of the throttle housing is fully closed. Any suggestions on how to fix?

[Geezer914]

Got rid of all that shit, the decel valve and the charcoal canister.. Just have a hose from the oil fill neck to the throttle body boot and kept the auxiliary air valve.

[rjames]

Got rid of all that shit, the decel valve and the charcoal canister.. Just have a hose from the oil fill neck to the throttle body boot and kept the auxiliary air valve.

Keep the decel valve as long as it's functional and you can set it properly. It should help extend the life of the MPS diaphragm.

[wonkipop]

Got rid of all that shit, the decel valve and the charcoal canister.. Just have a hose from the oil fill neck to the throttle body boot and kept the auxiliary air valve.

Keep the decel valve as long as it's functional and you can set it properly. It should help extend the life of the MPS diaphragm.

no mps in a L-jet. so decel is not as critical as it is in D jet.

however agree with you, there is no need to get rid of the decel valve.
@Van B has successfully adjusted one to the correct level.

but this is not his real problem?
his problem is the car only starts and runs at this idle level and dies as soon as he gases it.

the decel valve is elevating the idle level for sure.
if it was adjusted correctly idle would drop.
but.......it would still have the problem of not running once the tps switch comes off idle.

test would appear to indicate that the AAV is working as it should. maybe.
i imagine the engine was still cold when he did this test for us.
eventually it would probably have closed and the 3000 rpm would have dropped slightly. later on he can test his AAV to make sure its closing properly.
but not critical at this stage.
its not his real problem.

he can now move on to the next test which i have described in further post.