Can we get a brainstorming session going here in regards to a weird cutting out problem i am experiencing. Symtoms - While boosting up from low Rpm at wide open throttle more often in 3rd and 4th but sometimes in 2nd it will completely cut out. It cuts out instantly untill the revs drop down or you clutch it and giveit a few revs. When it cuts out you cant rev itm it feels like someone has just turned the key off. There are no other symptoms, no loss of idle quality or power. and it will not do it every time, say about 1 in 10 power runs. it has never happened at light throttle. Tests done - New fuel filter, then fitted fuel pressure gauge. fuel pressure is spot on , goes up under boost and remains constant. Manifold boost gauge shows that no heavy spiking is occuring during this situation. I tried another S1 PTU, just in case, no change. My thoughts - Well i know its not a problem on the fuel delivery side. the gauge proved that. The fact that it only does it rarely indicates that its not a mechanical problem . And its not overboosting or leaning out. I guess that leaves us with CAS, ECU , engine loom and other wiring. fire off any suggestions even if they seem silly.
Def not spark plugs. First peice i would swap out is the ecu . Also i would swap out all the electronics, ptu cas etc.. to rule them out, then move on to the wiring loom, its def electrical in nature. Regards Trev
Yep, nasty cut out. Foot flat to the floor and it was as if the throttle was completely shut. Would kick in again after it got below the 2500rpm AFM level and then work againg for a while, then cut out etc.
Sounds very similar. Ill clean and check the connector tomoro. there will be some girly drinks for you if your right
i just cleaned the afm contacts. went for a good drive replicating the same situations and the fault was not present. 90% sure you pegged it chris
AFM? I wouldn't be surprised if it was the AFM itself. I've seen some weird symptoms over the years. One Z would cut out doing left hand turns but worked OK otherwise. Replacement AFM fixed it. I'd try replacing the AFM with a spare if you have one, or can borrow it for a while.
read these two threads. The answer will be in there. http://www.aus300zx.com/forum/showthread.php?t=262685 http://www.aus300zx.com/forum/showthread.php?t=260341
Cutting out I had a similar problem , Check ,swap ptu , and check turbo timer/imobiliser/ wiring . good luck
Those threads seem to be the same problems but i find only more questions, not answers. How did you fix yours tekkie?
I'll put down a 20 buck bet that you're hitting the stock max theoretical pulse width! If the max TP is reached (normally due to more boost/breather mods and no tune) the ecu will cut spark and you'll be like... WTF was that!??!?!
Play with the CAS connector when idling, if it stumbles or cuts then the connector needs to be fixed or replaced. I had this symptom on the black car. Could also be as mentioned your hitting max airflow limit set in the ecu (so many argue with this) If you've really wound up the boost and this figure hasn't been changed then you'll hit it around the 18lb mark.
I think you guys may be right, the car is going so well that just before it cuts out you feel like your going to go forward in time! The ECU has been retuned so i was hoping i wouldnt encounter this sort of thing. It spins 2nd gear in the dry when it hits full boost.
In the end, It turned out my boost gauge was reading low, and I was boosting to 18 psi when it should have been 13 odd. I readjusted the manual Boost controller to 13 PSI problem disspeared. Expect it is a fuel pump issue which will rear its head again when I put the 650's in and push the stock turbos back to 18 PSI. I recon Zrated has a valid point. I would have been way past max pulse width on the injectors. The car was a missile right up till it cut and you would get thrown forward in the seat when the cut came.
