Poor idle and missing while cruising??

[rishar1]

1990 300zx N/A The car has a really poor idle and will stall out occasionally. It is also missing while at cruising speed. If I'm driving on a flat road and not accelerating the car will start to miss, then if I let off the throttle all the way and then get back on it will run ok for a bit. I've tested the IAC and the solenoid works fine when I put power to it but I'm not getting voltage up to it. I was planning on rewiring it from the ecu but I can't find the pin diagram for the ecu connector. As for the miss at speed I have check all the connections on the coils, injectors, PTU, and the MAF sensor. Ran it on conzult and am getting a code 55 so all should be good there. I'm just out of Ideas any help you guys could suggest would be a great help.

[t.mcginley.jr]

Have you checked the injectors themselves? Ohm test them with a multimeter, they should each be between 10-14 ohms. If not they are bad. It also wouldn't help to take off your MAF and clean it with MAF cleaner. Besides testing the IACV, have you taken it off and cleaned it?

Also, did you calibrate the TPS? http://z32.wikispaces.com/Throttle+Posi ... 0the%20TPS

[rishar1]

The Injectors ohm within specs. I had replaced them about a year ago so they should be alright. Tryed cleaning the Maf but no luck there, as for the IACV I pulled the hoses loose and sprayed thin inside down with cleaner, and then a little pb blaster for lubricant. I set the TPS and timing a few weeks ago so I'm pretty sure they are in spec but I'll check again.

[t.mcginley.jr]

What did you set the timing at?

Also, have you tried just doing a power balance test while it's idling? Like pulling coil pack connectors one at a time and seeing if the idle drops? Could be a bad coil pack or loose/broken connector

[t.mcginley.jr]

Enough carbon buildup on the throttle bodies could also cause idle issues

[t.mcginley.jr]

Oh and how old are your PCV valves? If they're old and clogged that will definitely mess some stuff up

[rishar1]

Timing is set at 15 BTC. Ran power balance on conzult and everything checks out there. Throttle bodies were thoroughly cleaned. PCV valves need to be checked don't know why I didn't think of them. I'