runs rough at start up

[chilinetc]

I installed an engine from an 84 300zx in a datsun pickup. It will fire up great but until it's warm it runs really rough. I think it's a sensor or something but none of my manuals show anything.

[nissanfreak12]

Possibly coolant temp sensor, but your in the wrong section. Hopefully a mod will move you to the correct section so you can get more help.

[Ziggy1621]

Any lights? Take it to Autozone and have them plug up the OBDII

[chilinetc]

I"m not sure what is ment by I'm in the wrong mod. It could be a coolant sensor I was unable to use the radiator from the car if the sensor is in the radiator?

[chilinetc]

I guess I forgot to mention I put the engine in an old datsun pickup so thier is no lights so their is also no way anyone can put a reader on it. It does have the computer but only to run the thing nothing for diagnostic it is an 84.

[t.mcginley.jr]

He meant you're in the wrong section of this website. You're asking a question about a Z31 engine in the Z32 tech section. No idea about the Z31, but the Z32 temp sensor is threaded into the coolant hardpipe on the front of the engine. It could also be green corrosion on the electrical connections

[chilinetc]

I didn't realize thier were two different engines. I guess I'll go back and find the right section to post in. I do not have a coolant hardpipe not that I've seen and ther is also no sensors on the front of the engine. Are you sure it's a coolant sensor? to me is feels like it's starving for fuel.

[chilinetc]

I did find a place for a sensor on the hard pipe that I said I didn't have. But thier is no sensor thier broke off. In the schematics it says it goes to the coolant fan and that's it. I have a different fan and sensor. Should I repace that sensor? I know it was installed when I first installed the engine but I remember last year it came apart so I took it out. But it's always ran rough since I put the engine in.

[t.mcginley.jr]

If a coolant sensor is bad, the ecu doesn't know what temp the engine is at so it messes up the air/fuel its feeding the engine, hence why it could be the reason its running rough. Put a new sensor in and see if it helps... they're usually pretty cheap.

[chilinetc]

Thankyou. It should be easy enough to do.