deonw1

So, I have an 85 Z31 N/A that has a difficult time starting when cold. If I let the fuel pump prime a few times before starting or use starting fluid she will fire right up. She will also stay running and restart without any issue for the rest of the day. I have installed a new fuel pump, and FPR, checked the fuel pressure, spark, vacuum, and the ECU is clear. Everything seems to check out as per the FSM. The only strange thing I see is the FSM has 2 different configurations for the FPR fuel hose routing, one for turbo and the other for N/A. I have an N/A that appears to be routed like a turbo. Any input would be greatly appreciated. Thanks

NismoPick

Welcome to ZDriver! So when you check fuel pressure, what's it at? Did you do a leak down test?

87moonglow

Hey everyone, and to op, sorry this is diff from what u guys are talking about but have u changed the thermostat or is it even still there?

deonw1

When it first primes the pressure is at 34 psi and after starting ~25 - 26 psi. And yes, I did a leak down test, but I forgot the exact time frame it took for the pressure to bleed down, but it took over an hour. I may have to do the bleed down test again to get you a more accurate answer. I read on post that someone had a similar issue and removed the fuel return line and it help. Possibly some blockage in the return line? Thanks again for your help.

deonw1

No , I haven't changed the thermostat, yes it is still there and working as far as I can tell. So what's your theory?

87moonglow

It would generally take longer for the car to warm up, and now that I rethink that, it would only effect the coldstarts after the engine has been running, Im not positive though about the latter tho. Another brainstorm would be the MAF/ throttle body being dirty (maybe IDK) iv cleaned mine before and it helped my idle/coldstarts slightly