RB20 DATSUN HESITATION

[tylerd280zx]

I swapped a rb20det in my 280zx. i have a wiring specialties harness,fmic,rb25 turbo, new rb20 maf, 12pound flywheel,spec 3 clutch, fpr,new plugs, aftermarket intake.....maybe missing a few items. My problem is when the car is at an idle and you give it the gas it drops rpms for a sec or 2 then revs. The rpms drop quick and if its already revd up alittle then it doesnt hesitate. but at an idle it does and wehen your next to the intake it makes a odd sucking noise when it does hesitate. Also when you first start it you have to give it throttle or it will just crank (try to start but wont).iv been having some problems with the idle dropping randomly to 400-500 and acting like its wanting to die and sometimes it does then it will kick its self back up and idle fine for 30 sec and drop down again. I started it yestarday tho and idled fine the whole time so i dont know. I put the fpr on since my plugs were really lean and after it feels like i hit a wall at 4k rpms.My ecu reads 55 so im not sure.......any help would be great thanks
*****Also cleaned the iacv not sure how great but did clean it.

[Yellow4g63]

Did you check your tps? and check for any leaks?

[tylerd280zx]

Not really iv unhooked it while it was running and car didn't change (not sure if it's suppose too)

[Yellow4g63]

Check the voltage for closed and wot. I forget what the range is tho but you should be able to find it with a google search.

[tylerd280zx]

Thanks will do and I'll let you know

[tylerd280zx]

So I checked the voltage on the 3 pin connector going to the tps. Has the red white and black wire. 5.5 when closed and 1.2 when wot....did I check the wrong connector?

[Yellow4g63]

That's reversed voltage should be low when closed and high when open.

[Carl H]

awwww.
harness is pinned wrong, simply swap the outer two pins on the oval tps connector.
make sure the idle switch is engaged and making contact, i typically set idle switch and let closed voltage be whatever it is on 20s.
on the tps body connector make sure the two pins that have wires have continuity with the tb closed and when its cracked open it breaks continuity.

[tylerd280zx]

Can't get pics on here or I'd show you

[tylerd280zx]

The wiring specialties harness has a 3 prong oval connector and the wires are yellow white then black....the car plug plugs into that is red white then black......there is a plug on the end of the tps with only 2 wires and they read 12 volts