RB20det Cuts Out

[Con-city_s13]

I've made my way through a maze of issues with my rb20 and I've come down to one last problem that has stumped me.

The engine starts and idle rather normally. When cold the engine runs well. After a about 20 minutes of driving (or enough to get heat built up), the car does not want to accelerate under heavy throttle. It tends to hesitate for a moment when the throttle opens, and under heavy throttle it will cut out intermittently. I have to lift off the throttle and ease back into it to keep the car moving.

I have replaced/installed: adjustable FPR w/ gauge, fuel filter, ignitor chip (used j30 unit), tps, walboro 255 lph fuel pump, spark plugs (check out clean), MAF, and a wiring specialties harness.

Some concerns I have are the MAF and the oxygen sensor. The MAF is some knock off j60 (OEM) unit and I am unsure of the quality. I initially place the wideband oxygen sensor on the OEM turbo elbow, exposing it to too much heat.

If anybody has any idea of what my problem could, I would greatly appreciate it. A little help is better than no help.

[40craz]

Did you get any leads on this I seem to be having the same problem with my rb25

[Sileighty_85]

Check Coolant Temp sensor

[40craz]

I just bought a brand new ka sensor for mine

[Con-city_s13]

Update:
I have replaced the coolant temp sensor and the ignitor with a brand new Nissan part and I am still having issues.

I'm beginning to think it is a tune issue. After replacing almost every sensor on the engine, I am running out of things to blame the issues on.

[Livinstrong]

Did you make sure your base pressure on your fuel system is the same as stock? If not you could be sending more fuel into the engine than then ECU knows and causes bogging under heavier throttle.

[Con-city_s13]

I've messed around with fuel pressure and it seems to have no effect on the issue. My AFR gauge reads lean when it starts cutting out.

Upon further testing, I took a look at my tps again and noticed there was no continuity between the power prong and either the ground nor the signal. This is true for both the new and old sensor. To me this seems wrong. Does anybody have any input on this?

[OutToWinPAHC]

How certain are you the TPS range and timing at idle are correct... What plugs and plug gap are you using?

I use .40 VDC TPS throttle closed with a calibrated Fluke 189, then run to op temp, unplug the 3 wire TPS plug and lock timing at 15 degrees BTDC. Plugs I use on my RB20 are BKR6ES at .8mm gap or .031inch

[Con-city_s13]

I have bcpr7es spark plugs gapped at 8mm. I set timing to 15 degrees past top dead center, but the engine will only idle around 900 rpm.

[OutToWinPAHC]

Idle as oer the fsm is like 650 I adjusted mine to 850 by the iac screw

[smoked240]

On my rb25 I was having the same issues you were and I replaced my o2 sensor and it worked. My car would die and not start for about 5 mins and I could barely give it any gas. I would also get it tuned with a good ecu. After I did that mine runs amazing

[Livinstrong]

I would also check out the TPS voltage reading with a digital multimeter. I was having a lean/choppy running issue under partial/heavy throttle but ran fine full throttle when zimfirst got my SR running and it was a misaligned TPS sensor. Simple and free fix