944#447

The engine fires but seemingly in the wrong order- it starts and stumbles to maybe 400 rpm while it misfires and eventually dies. If I give it any throttle it will just start to rev while misfiring for a second, and then just shuts off.

when it dies the fuel pump continues to run

I have tach bounce.

The coil has 12v, 5600 ohms and 0.5 ohm across the terminals. New wires and plugs, cap and rotor. No change.


Does anyone have a DME that I can borrow or rent? Thank you very much

931guru

Check the work you just did. Rotor setscrew in place? Plug wires in proper locations on the cap? Cap securely mounted onto the cam sprocket cover?

944#447

yes it ran the same before changing those parts (no change)


I can rearrange the spark plug wires and it runs the same, out of time

GPA951s

Double check your timing by looking at the flywheel tdc then route your wires… looking at the front the rotor should point to the bottom right.. the little part that goes into cam “can” be out.. i ran into that one time. It should only go one way but i have come across one that was 180 out.. ( 2 holes drilled) not sure why.. as long as youre checking tdc check the cam to make sure its in the right spot.

Porsche94483

944#447

Timing mark lined up in the notch and dizzy rotor pointing at number 1. Timing looks spot on. I’m nearly positive now the “missing” is just flooding.


what else could cause the fuel pump to continue running after it stalls and the injectors to spray too much fuel?

GPA951s

You say it ran like this before you changed these parts. When was the last time it actually ran correctly?

ALEXTHEGREAT

I'd remove the fuel rail and place the rail with its injectors into a bucket. Crank the engine and check the spray patterns. Maybe you have one or more injectors that instead of creating a super fine mist spray pattern, they're literally dripping.

Chalt

My understanding is that the speed sensor keeps the fuel pump from running when the engine is off or rotating slower than 300 rpm. It's supposed to be that way as a safety feature. So if you crash, and the motor stops running, it won't keep pumping fuel.

That being said, if you are certain the fuel pump runs after the motor has died, logic would say the DME isn't telling the fuel pump to stop.

gwshark

@Porsche94483 does this wire cap configuration apply to 86 944 as well? I ask as my wires don’t appear to be aligned to this configuration and wonder if I am missing something. Thanks in advance.

944#447

UPDATE:
New DME fixed all the problems.



should be the same yes