cold start problem

[83 importturbo]

hey i bought a 83 280zx non turbo car they put a 81 turbo motor in . iv had it for about 4 month iv changed ecu,injectors and harnes,tps,coil,coolant temp sensor,fuel filter and cap ,rotor, wires ,plugs.still have problem when cold it takes a few times before starting when it does start low idle untill warms up.i dont have a cold start valve or air regulator. could that be the problem.

[e_racer1999]

probably. also, do you hear the electric fuel pump? could be on its way out...

[83 importturbo]

yes i checked fuel pump it turns on and got presure 36psi and up.

[zbane]

By "air regulator," what do you mean? Have you any photographs of the engine that we could look at?

The two items in the bay that I would associate with air regulation would be those circled in these photos.

Regardless, you do need to have both of them.

Do note that I do not have a turbo engine, so your bay will be more cluttered than mine. The base location for both items will be about the same though.

[sblake01]

David, your first picture is the air regulator and cold start valve in the circle. It wouldn't start up and run without the air flow meter circled in the second picture unless he's done some modifications that I'm unaware of.

[zbane]

Absolutely correct (of course) Stephen. I was just looking for some clarification on the poster's part as to help find the problem.

From the FSM:

Shutter is open during engine warm up, thereby increasing quantity of intake air causing engine speed to increase. Engine speed is decreased when passage is narrowed...After warm up, the shutter closes.

Richard, how were the openings meant for the air regulator dealt with?

If they have simply been plugged, try unplugging the manifold side and then try to start the engine up.

[sblake01]

Together, the cold start valve and the air regulator act like an automatic choke on a carbureated car. You'd have to plug off a few lines to eliminate them. I'd be curious to see a picture also since a 81 turbo motor is set up differently than a 83 n/a. The 83 would have the ECCS and wouldn't have a cold start valve because that function would be in the ECU which is more 'computer' like than the 81 ECU which wouldn't contain that function. So if you have an 81 engine in an 83 there's going to be some electrical issues because the cars used different EFI systems. Your ECU will be looking for signals from components that didn't exist on an 81 engine, turbo or not.

[76Datsun280z]

The ZX's probably don't have Thermotime switches do they?

[sblake01]

The ZX's probably don't have Thermotime switches do they?

They did up to about mid 82 when they changed over to the ECCS system which had more functions in the ECU. These scans show the differences: