Missfire RB25DET MAFless tune

[KittoRB25]

So any help appreciated guys,

There's countless posts on misfiring on this site and I've viewed most of the ones I've found, to no avail.

Engine details:                                           RB25DET S1.5, ECU is Haltech E11V2, running a MAFless tune, Garrett GT3582R, Upgraded Intercooler, GFB manual Boost controller, Tial EWG 63mm, Nismo 740cc injectors, 3BAR MAP sensor, Bosch 040 fuel pump, Sard adjustable fuel reg (with gauge (set at 55psi) HKS Oil cooler and remote Oil filter, Splitfire Coils, NGK Copper plugs gapped at .8 with 21KMs on them.

So car developed a missfire last week, over fueling, hesitating at all operating temps (biggest from TPS 0 to >2) from startup to shut down with a rich and lean pops in exhaust, surging during acelleration and cruising. Checked usual culprits in order; Coils, Plugs, Tune re install, Vacume and hoses, Fuel Reg, Compression test, Injectors Flow tested and inspected All okay, TPS sensor, Coolant temp sensor, Air Temp sensor, MAP sensor, related wiring, AAC valve, replaced Fuel filter, and ECU checks out.

Nowe I havnt done the CAS, as I was under impression that a faulty cas will cause problems with starting, and it starts like nothings wrong. The BOV has been on for 4 years (was on car when I got it) and never had an issue with it before) have checked to make shure Diaphragm in Fuel reg isn't totalled and it's all fine. And no it hasn't had an o2 sensor on the exhaust (ecu) since acquiring it. The air fuel mix at idle is around 10.8:1 richining on throttle depress. All sensor have been tested with Multimeter and viewing on the Ecu both are in sync.

Cars in Red Center Nats in a month so would like to have it run by then.

Any help appreciated                                             

Edited August 1, 2016 by KittoRB25
Grammar

[KiwiRS4T]

Take the CAS off and spin it by hand. You will feel if bearings are stuffed. I replaced one on a car that started fine but ran rough until the CAS was replaced.

[KittoRB25]

Cheers, taken off and no audible sound from the CAS, also checked on the Ecu and it's providing a response to the ecu.

Edited August 1, 2016 by KittoRB25
Development

[Dose Pipe Sutututu]

check your base timing and if it's sync'd with the ECU when the timing is locked (for syncing)... I've heard stories where Haltech E11s going nuts and the triggers angles magically get corrupted.

If it's whacked, I suggest going back into your tune and seeing if the trigger angles are correct.

[BK]

I have spare crank angle sensor if needed from my GTRs. When you say checked plugs, you do mean tried another set of plug right. They are pretty old plugs for coppers. What heat range for your R33 gts-t as any colder than a 6 and you will foul them on rich tunes like you've got. 10:1 at idle is way too rich mate. Also check your actual MAP sensor is working correctly. I assume you can check the voltages within the ECU are normal. I had an Apexi one die this year on my 32

[KittoRB25]

11 hours ago, BK said:

I have spare crank angle sensor if needed from my GTRs. When you say checked plugs, you do mean tried another set of plug right. They are pretty old plugs for coppers. What heat range for your R33 gts-t as any colder than a 6 and you will foul them on rich tunes like you've got. 10:1 at idle is way too rich mate. Also check your actual MAP sensor is working correctly. I assume you can check the voltages within the ECU are normal. I had an Apexi one die this year on my 32

Not 21,000KMs i meant actually less than 30KM's. Yes checked map sensor and heat range was 6, had 5s in previously and am waiting for some new parts to arrive. Ive put 5s back in it (new ones) as im under that feeling that they were barely managing with a 5 heat range. Ill keep it posted on re start.

[KittoRB25]

Just closing this off. Conclusion raised is leaning on misstune, brought to light by the replacement of a sensor that must of been faulty at the time of tune.

[KiwiRS4T]

Which sensor? Also believe there were a lot of fake Sard FPRs around...- Running OK now? What are you making with the 3582?

[KittoRB25]

1 hour ago, KiwiRS4T said:

Which sensor? Also believe there were a lot of fake Sard FPRs around...- Running OK now? What are you making with the 3582?

Air temp intake temp (after intercooler). Nah genuine SARD and havnt had figures yet. Car has been parked up since after Red Center Nats #02, bought a house and a motorcycle and at long last got of my ass to drain the tank of old fuel before i send it south next month.

Yes thats a long ass siphon hose

Edited June 12, 2017 by KittoRB25
Grammar

[KittoRB25]

On 12/06/2017 at 8:50 PM, KiwiRS4T said:

Which sensor? Also believe there were a lot of fake Sard FPRs around...- Running OK now? What are you making with the 3582?

Reviving a necro thread.

went go a safe tune at 18psi and walked away with 322 RWKW on 98

Edited July 14, 2019 by KittoRB25