What did I do or miss?, All better now! Options

[arne]

Background - I got the engine in my '73 2.0 (D-jet) running a while back (after several years slumber). It actually was running pretty decently, other than a spastic AAR. But it had many oil leaks, so I dropped it to get to everything easier.

While it was out, I replaced all the vacuum lines, and a bunch of oil seals and such. AAR was disassembled and refurbished (as best I could). Eliminated the decal valve. No other injection work.

Now that the engine is in the car, it is running way rich, even when warm. So much so that it loads up after a bit and won't rev, and left to idle it will load up and die. AAR now appears to be working fairly well, once warmed there is little or no vacuum at that hose.

Since there really weren't many changes, I'm thinking this must be something fairly simple. Any suggestions?

[Dave_Darling]

A few things that come to mind that would make the mixture overly rich:

- CHT sensor unplugged or high resistance somehow.
- MPS does not hold vacuum, or hose to the MPS is unplugged or has a large leak.
- Fuel pressure is too high.
- Throttle switch is mis-adjusted, causing extra injection pulses.

Other things can cause it as well. Some of them are very weird... A few that have happened to me:
- Trigger points bounce, causing multiple injections.
- Failure of output stage transistor in the ECU, so the injectors do not get closed. (Warning: Can hydro-lock the motor!)
- Fuel pressure regulator hooked up backwards, leading to 50+ PSI fuel pressure.
- Intake valve seat failure, resulting in lots of blowback into the intake, raising the manifold pressure and richening up the mixture.
- Cold-start valve has failed open, spraying fuel into the intake all the time.

--DD