Hey all,

Just got a 91 R32 GTS4 on the road last week, and having issues with breaking up. Im going to list the mods, the symptoms, what i have done to try and fix, and where its gotten me. Thanks to all the contributors the the board for the info thus far.

I got the car a few weeks ago, but have no way of contacting the owner. I bought it through a 3rd party.

Rb20DET GTS4
Automatic Tranny

HKS SSBOV
HKS Pod filter (ripped rubber)
Test Pipe
3" Exhaust
Some kind of replacement coil loom (looks like wiring spec)
Stock Turbo??

-Car breaks up above 40% throttle. If i ease into it, itll pull until about 5000RPM. Cruising at highway speeds, the exhaust had a steady tone, with a faint pop every second or so. Gas Mileage is bad, but i also dont know how these cars drink gas when driving "spiritedly".
-Hicas light comes on, after a few miles of driving. I checked the PS Fluid level, and it seemed ok. The car definitely needs an alignment though, as the wheel isn't completely straight while cruising. Going to get new tires, then have an alignment done.

Popping the hood, reveals a removed spark plug cover. The ingnitor is "mounted" to the firewall with zip ties. 3 of the 6 stock coils had heavy heavy build up on the contact points. The plugs looks black, but not terrible.

I replaced the plugs with NGK Bpr6-11. Didnt change gap (probably will go to .08 when i install the new coilpacks.)
-This made the car run "different", not def better or worse. just different.

I ordered a new complete set of Coilpacks. While i understand that probably only some of them are toasted, i figured on a 25 year old car it worth replacing them all. The packs on the car still say Nissan on them. I have no way of knowing for sure, but logic tells me at some point the previous owner bought a new set of performance coilpacks with a loom. They discarded their stock loom. When selling the car, they reinstalled the stock coilpacks, but left the new loom in because the old one was gone. The spark plug cover is in the trunk. Half of the bolts for the coilpacks are missing, some only have 2 bolts holding the pack on. None of them have all 4 bolts. All the hardware for the plug cover is gone. (the cover is in the trunk however).
-Will put in the new coilpacks, and reinstall the cover and mount the ignitor to the top of the cover. I bought new hardware from local store to remount everything

The HKS Pod filter has a large tear in the rubber part behind the filter, but before the entrance to the maf. When i give it throttle, i can hear the air being sucked into the small gap. Different sound than typical....sounds like a suction through a straw.
-Will buy a new pod filter. Will probably try and duct tape the gap in the one i have now, to see if it will help. Obviously, this is not a fix, just more of a test.

The previous owner, at some point, had a different kind of MAF in the car. I know this because they added a 2nd plug to the harness, but never removed the original plug. They pretty much Tee'd into the harness, and made it so a different MAF can simply be plugged in.
-Will, carefully, open up the harness by the MAF and remove the 2nd plug. Solder and heat shrink everything. Im sure that having the 2nd plug there is creating a decent amount of interference and noise for the ecu to have to deal with. Adapter plugs are cheap enough now, that if i ever need to switch to a Z32 or whatever, i can simply do that.

If these corrections do not fix the issue, i will move onto installing a relay for the fuel pump and getting a new fuel filter. I will probably get a new fuel filter anyway, to just know its been done.

Any tips or suggestions are welcome. Thanks ya'll

That is a very detailed post and should help the experts here give you good diagnosis if your planned fixes don't work. But anyway here are my thoughts.

That pop you hear is misfire. You definitely have ignition related issue, sort that out first and foremost. Carry on with your coil pack fixes and you should see improvement. The plugs should be gapped at .032", not sure what that is in mm.

The HiCAS is sensitive to bad alignment, so get that done. Also, if your car has aftermarket steering wheel, check the boss kit. The bolt pattern on R32 is unlike most aftermarket kit and will throw the HiCAS off.

Good luck.

Wow...I thought I was the only A/T GTS4 in the USA. How do your plugs look? Is it an oem ignitor? The aftermarket ones are garbage. Coilpacks will arc to the metal bracket...there are many links showing how to fix this ,,,basically coating the coilpack with silicone and painting the brackets so they dont arc. I had a strange dead cylinder and found it to be a burnt resistor in the ecu...may want to pop it open and check for burns and what not.
Sounds like a bad MAF. When i upgraded to my enthalpy tune, it was written for z32 maf...i installed everything including my P2M 'reconditioned' OEM Z32 MAF...car idled great, pulled to about 4,500 rpm and fell on its face after....tried an old used z32 maf in desperation and problem solved.

GreyZ33Track wrote: ↑

Wed May 03, 2017 8:21 pm

Wow...I thought I was the only A/T GTS4 in the USA. How do your plugs look? Is it an oem ignitor? The aftermarket ones are garbage. Coilpacks will arc to the metal bracket...there are many links showing how to fix this ,,,basically coating the coilpack with silicone and painting the brackets so they dont arc. I had a strange dead cylinder and found it to be a burnt resistor in the ecu...may want to pop it open and check for burns and what not.
Sounds like a bad MAF. When i upgraded to my enthalpy tune, it was written for z32 maf...i installed everything including my P2M 'reconditioned' OEM Z32 MAF...car idled great, pulled to about 4,500 rpm and fell on its face after....tried an old used z32 maf in desperation and problem solved.

z32 maf? ive heard of people using the z32 maf. is it different to install compared to the oem one? is there a difference to be had this way? im just curious honestly. ive got a 90 gts-t type m in USA also haha. im also having an issue with the ignitor, it is intermittently working when the car gets up to operating temp. cutting from 6 cyl to maybe 4 or 5 cyl. already checked my coil packs and they all ohm'd out just fine.

People run Z32 MAF because it can measure more air and good for 300hp+ each, not because it's better, and it's not a plug and play. Z32 MAF are 80mm diameter so you will need aftermarket tubing, and the voltage quantifier is different so it needs to be tuned. But if you run Nistune then it's in the drop down menu, should be able to simply select it and go.

The ignitor is usually dead or alive. If you have intermittent issue, your coil pack may be arcing. All you need is a tube of dielectric grease to prevent that, it's a simple and cheap process so do it first before replacing the ignitor or coil pack.
https://youtu.be/Qirx_G4x5i0?t=235

Thefloatplace.....you ever figure it out? My car is stalling out when I hit bumps now...weird.