R34 - new acceleration/ idle problem

[Danowner]

Ok. So I've made another post about my car not idling properly, being generally rough and having hesitation when accelerating. Now, if you've seen my other post, you'll know that I've changed my spark plugs, put some spitfire coils in, cleaned the AFM and everything was running fine still. The car still ran and was drivable. Now, only since I took off the TPS and tried cleaning it, the car is no longer drivable. No freaking clue why my tps would do this, but now when I press the accelerator, the car almost dies. It's responding to the tps changing resistance, but it's as though it's being flooded with air or something. But when I press it, the idle doesn't go back up, it stays at that certain rpm range. The video of what I'm trying to explain is at the top. Really need some help as I need my car to at least be drivable for tomorrow. Cheers.

[GTSBoy]

TPS would appear to be maladjusted.  Should read ~0.45v at closed/idle.

[Danowner]

So why is it when the accelerator is pushed, it sounds like the engine is 80 years old and about to die? And would that also explain why the TCS and Slip light is on? Or is that a problem on it's own?

 

[GTSBoy]

Can't tell you exactly why the engine plays up when you blip the throttle. Probably depends on which direction you have it maladjusted.  Suffice to say, that the ECU needs to know where "closed" is and needs to know where "not closed" is (ie, everywhere else!) and uses that knowledge to decide whether to be on the idle maps or running on the main maps.  Needless to say, it won't run well on the wrong map.

You need to put the ECU into diagnostic mode and see what/if fault codes you have in there.  The ECU will report on the TCS DTCs that affect it.

Also, which TPS did you f**k with?  The engine's one?  Or the one on the TCS throttle?

[Danowner]

Haha okay so I was a dipshit and when I put it back on, I did it so when you press the accelerator, the little thing that would push the tps would not move at all, so the engine had no Signal coming from the tps at all lol. I took of the tps in line with the actual throttle body tensioner and all that. Got the car running nice now, idle is back to the old problem of being rough and still hesitates, but the car runs. Back to square one. I think it might be either afm or the ignition coil harness

[Danowner]

**Update**

So it ended up being the fuel pump, I'm sure these symptoms would be the same with a faulty fuel pump, but turns out my problem was just because the pump hose that sits in the tank had ripped open due to how it was mounted to the bracket, so it was loosing a shit tonne of pressure. All fixed now and mounted correctly. I'll attach the before and after pics

[KiwiRS4T]

Good result