help

[mtghost]

ok 78 z po had put on carbs because fi had "problems" saved all old fi parts, great i got the bright idea to put it back to fi, got it all back toegether and finally got it to run sort of seems to run well up to half throttle then get realy rich black smoke , if i remove the boot between air filter and air flow meter and hold the afm flap at about half open wow does it ever run great but let it go open and it runs terrible help with any ideas, ps my fuel pump runs constantly when key is on, thinking po rewired it when he done carb swap does it matter??:stupid:

[Zed Head]

Have you measured fuel pressure? The PO might have installed a low pressure system for the carbs.

Check your TPS for the smoke, it might be mis-adjusted.

Better yet, you should sit down at the ECU connector with an ohm-meter and the FSM, and check all of the circuits for proper resistance. That will tell you a lot about the state of your re-installation and whether all of the wires are still connected properly. It won't take that long and you'll know a lot more when you're done.

The PO would not have needed to rewire the fuel pump circuit since 78 uses fuel pressure and alternator to check if the engine is running, but might have done it anyway. It's not supposed to run all the time when tyhe key is on, only when the engine is running.

[rcb280z]

Boy there could be lots of things going on here. I did the same thing with my 77. Ran su's until I could figure out and test every FI part, componet. I know there is a fuel pump cut off in the AFM from 75-77 but not sure about 78. You might want to start there regarding the fuel pump running after shutting car down. My AFM had been richend so much that the cut off was not working. You could pm me your phone number and I could run down everything with you on what I had to do. It's a long list. My 77 is running cleaner than my 05 altima! and has great power. That was hard to accomplish here in CA with the smog laws. Let me know if you want to talk.

Bob