help chasing gremlins

[tungaz]

Hi everyone! This is my first post as I just got a z32 TT it has t28 turbos, dual pop, stillen intercoolers hks exhaust, I'm having an issue with it running weird at low rpm, if I'm cruising in 5th gear going any less than 70 it stumbles and feels really rough, I ran codes and found nothing, checked plugs and they are new iridium's, all coils are firing, injectors are all working ( not sure what the flow is like as they are the originals) o2 sensors tested fine, I did check the timing and it was set to 20°btdc I set it to 15 and it ran terrible so I set it back, I also did the flower pot mod and it didn't help. Just wondering where else to look also any reason as to why tHe timing is messed up?!?!

[Metacom]

Crank angle sensor might be going out?

Are you sure the timing belt was installed correctly?

[tungaz]

I wasn't sure about the t belt, so I just did a 120k service, and spent a lot of time making sure the belt was perfectly lined up. The timing is still off, but I got it running a lot smoother, it still stumbles at low rpm. Cleaned, retaped and greased all the electrical connectors on the ptu and cas with no luck, I ordered a cas and ptu from a salvage yard for cheap so we'll see.

[nissanfreak12]

You said you have Iridium plugs in the car, what brand and model? These cars do not like any other plug than;

http://www.conceptzperformance.com/Cart ... 24.8.10.58

That could cause issues like you are describing, along with timing, but the timing will cause it through out the RPM range. When you are checking the timing, do not use the loop by the PTU, sometimes it doesn't read correctly. Use the one right off the #1 cylinder.

If you did the timing belt, don't rely on the marks on the backing plate, you need to rely on counting the cogs in between the marks on the pulleys. The marks on the backing plate are just for a reference to line up the marks on the pulley. If installed correctly, the marks will actually be off.

[tungaz]

I changed the plugs to the NGK Nissan branded plugs from z1, I lined up the tbelt marks with the marks on the cogs, and didn't pay attention to the marks on the backing plates. When I set timing I'm using the thick wire from cylinder 1, letting the car warm up fully so temp gauge is showing about halfway, and rpm is below 950. The best results I've gotten are showing 30° btdc, the car runs very smooth under normal driving but maintaining speed in high gear is very jittery, also it has started taking its time to fire up, today it started up fine but while I was sitting at a light it stalled(has a 6puck clutch which I'm not too familiar with yet...) And wouldnt start back up, I fiddled around with the ptu harness, cranked it for a solid 15 seconds while giving it some gas and it started up again and got me to work without issue... So I'm pretty thoroughly stumped. BTW it does have dual pop charger but the ecu is chipped for it and I've done the flower pot mod so I don't think that's the issue, also the injectors appear to be original though I did listen to each of them and they are firing and sound pretty strong.

[Z32mike]

Bro my car had that same issue except I have 740cc Injectors, I have pretty much the same mods, I have turbo back exhaust, selin dual intakes, intercooler piping and ash spec intercooler upgrades, CZP chip, and I can't get my idle right, now it's to the point where my car doesnt idle at all and on 5th gear I either have to be giving it a little gas or off the throttle or it rides jiterry as hell.. I'm pretty much convinced that this car really does have an electrical curse and I'm about to go Standalone.. this is bananas..

[tungaz]

I actually got the the highway cruising situation fixed, I was running a doolz intake which I switched out for a separate setup. I swapped the ptu and cleaned all the connectors,The p/o was using an apexi safc which i cut out. Also I found out that my maf was faulty so I swapped it out. It now runs smooth like butter. The idle does fluxuate a bit but I haven't checked the timing since the changes so maybe that will help. And I've got some pintleless 740 injectors on the way since I'm still running the originals so maybe that will help even more.

[Ziggy1621]

For the idle flutter, have you set the IACV screw?

And welcome to Nico!