Sambo Posted October 10, 2017 Share Posted October 10, 2017 Basically, my 4age is running really, really rich. I paid a bloke to throw a pressure gauge on the fuel rail, which read really high. It's got a smallish external pump running up mostly standard lines to the fuel rail, standard FPR dumping to the standard return. Also has a standard ecu. When driving it has a bit of hesitation (from memory), and the throttle is quite binary, making it hard to keep a constant speed. It usually idles high (1000+), when it does idle close to where it should (~500) it's lumpy/rough sounding. Additional info: the car will run stationary all day with no problem (bar the clouds of grey smoke and afor mentioned idle issues). However, once it's being driven the fuel pump starts getting really noisy, the grey cloud gets worse and I think it gets so rich that it starts semi flooding/cutting out under throttle. - Does this sound like a potential symptom of too much pressure? In my mind, it should be worse at idle as it's using less fuel. Lastly, I've tried two second hand FPRs, run a temporary fuel return line (check for blockage etc) and spent hours and hours fucking around with it, any other suggestions? For all I know, I've solved the high fuel pressure, but the richness remains. The petrol in the tank is a bit discoloured and old, but smells ok, and the car starts really easy, even from cold. Quote Link to comment Share on other sites More sharing options...
kyteler Posted October 10, 2017 Share Posted October 10, 2017 Black smoke would be over-fueling, greyish smoke is more likely an oil issue? It's not got a ventilation/re-circ issue does it? Quote Link to comment Share on other sites More sharing options...
Sambo Posted October 10, 2017 Author Share Posted October 10, 2017 Thanks for the reply man, that's a good point. I'll shoot over to the car this arvo and reacquaint myself with the facts. The smoke definitely smells like fuel, rather than oil, but I'll take a video for your perusal and judgement. Quote Link to comment Share on other sites More sharing options...
bigfoot Posted October 10, 2017 Share Posted October 10, 2017 Is the fuel pump putting out too much pressure for the reg to bleed off? Saw that on the internet once Quote Link to comment Share on other sites More sharing options...
Sambo Posted October 10, 2017 Author Share Posted October 10, 2017 That's an interesting one. I can't actually remember which walbro pump it is, but it was definitely one of the smallest ones. That is a good point though, I'll have to investigate it further. Quote Link to comment Share on other sites More sharing options...
Nominal Posted October 10, 2017 Share Posted October 10, 2017 This seems somewhat similar (especially the noisy pump - does it get hot too?) to the problem I had with a 4AGE when the return line got kinked. Since you have run a temporary return it can't be that. I like Bigfoots suggestion. No chance that the actual in-tank return pipe is blocked somehow? What fuel pressure are you actually getting? Quote Link to comment Share on other sites More sharing options...
Testament Posted October 11, 2017 Share Posted October 11, 2017 +1 "really high fuel pressure" is not a number - what was the actual figure? the usual number is 43.5psi/ 3 Bar but some manufacturers occasionally run more or less. someone will know what a 4age is supposed to have if its different. if the fuel pressure is within a few psi of where it should be, then to run rich the ecu is telling the injectors to put in more fuel than the engine needs. not sure what the setup on your 4age is but it will be using some combination of air temperature, coolant temperature, manifold pressure, engine speed, throttle position and air flow (may use manifold pressure and speed, or a direct measurement via air flow meter). so would pay to check the wiring and the readings of those sensors where possible. if it is running overly rich everywhere, then at idle the ignition probably has enough poke to light off the mixture but not when under load so it will start running shit when you try to accelerate hard or go up a hill etc. Quote Link to comment Share on other sites More sharing options...
ajg193 Posted October 11, 2017 Share Posted October 11, 2017 Not sure if it has been mentioned/tried, but what is the condition of your O2 sensor? Quote Link to comment Share on other sites More sharing options...
Sambo Posted October 11, 2017 Author Share Posted October 11, 2017 To be honest, I'm not too sure about the O2 sensor, I had kind of assumed that the ECU wouldn't have enough adjustment to flood the engine. The fuel pressure was around 55psi iirc, I'll have it written down somewhere. The engine flooded this afternoon, then I flattened the battery trying to clear it, so no running video today. Quote Link to comment Share on other sites More sharing options...
chris r Posted October 11, 2017 Share Posted October 11, 2017 It's probably not the oxygen sensor there usually isn't enough fuel trim to flood it from o2 sensor input Most likely will be coolant temp sensor. Quote Link to comment Share on other sites More sharing options...
Sambo Posted October 12, 2017 Author Share Posted October 12, 2017 Would a reasonable test for the temp sensors be to pull the plug off and see if the running condition changes? I've just done that, nothing seemed to change. They're in a pretty shitty place to actually remove.. I also unplugged the cold start injector, that made no difference either, idling or driving. Quote Link to comment Share on other sites More sharing options...
chris r Posted October 12, 2017 Share Posted October 12, 2017 You can do that. Best practice is to pull it out and drop it in a pot of hot water and watch the resistance change. If it's smooth it's probably OK. You can try look up the factory specs a d compare ot 1 Quote Link to comment Share on other sites More sharing options...
Sambo Posted October 12, 2017 Author Share Posted October 12, 2017 I need to buy a deeeep 21mm socket... Quote Link to comment Share on other sites More sharing options...
chris r Posted October 12, 2017 Share Posted October 12, 2017 I've probably got one you can borrow. Pm me tomorrow to remind me to check Quote Link to comment Share on other sites More sharing options...
HighLUX Posted October 12, 2017 Share Posted October 12, 2017 E1 TE1 it http://www.troublecodes.net/toyota/ 3 Quote Link to comment Share on other sites More sharing options...
Nominal Posted October 12, 2017 Share Posted October 12, 2017 My official Toyota 4AGE book says 34-40psi with no vacuum to regulator. 55psi is quite a bit over that, so might be part of the problem. Quote Link to comment Share on other sites More sharing options...
Sambo Posted October 12, 2017 Author Share Posted October 12, 2017 Thanks Chris, will do! I've also decided to go all in and replace the fuel lines (10mm feed and 8mm return) and fpr. Will this mean that i also have to drop the tank and replace the pickup etc? Quote Link to comment Share on other sites More sharing options...
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