Serban Posted November 30, 2015 Share Posted November 30, 2015 Yesterday I tried to make it out to a yearly Nissan meet, and only got about a mile and half away from the house before the car died on me. Here's the back story, every once in a while, either at idle or while driving, the car would just flood out, wideband gauge pegged at 10:1, so much fuel that the car would just die, couldn't keep it running. My solution was always to unplug the ECU, crank it up, let it run a second till all that fuel was cleared out, reconnect ECU, and it was fine again! In the 2 years I've had the car, this happened maybe a handful of times, no big deal as it was always a quick fix. Yesterday on the other hand, there's no getting to stay on. I tried my usual routine, but nothing. I had my brother in law hold the wiper on the AFM clockwise, leaning out the mixture, and the car started and stayed running as long as he held it, once he let go, it would immediately run so rich, it floods out. I didn't have any time to trouble shoot. After spending a couple of hours on the side of the road tinkering with it, then waiting for a tow truck, my wife was not happy with me spending any more time trying to figure it out. Any ideas on this issue? Fixable, or is the AFM done for, and I need a new one? Bonus, here's a pic of my car getting loaded on a flat bed. Quickest $50 they ever made! Quote Link to comment Share on other sites More sharing options...
NewZed Posted November 30, 2015 Share Posted November 30, 2015 Because turning the AFM vane by hand fixed the problem, whatever it is, doesn't mean that the AFM is the cause of the problem. The old problem may not be related to the new problem. I would troubleshoot more. Could be a simple holed FPR diaphragm. Quote Link to comment Share on other sites More sharing options...
Serban Posted November 30, 2015 Author Share Posted November 30, 2015 Pretty sure fuel pressure was in the mid 40s psi during this whole ordeal, but I'll definitely take a look at the fpr. I'm still using the stock one, but I've got an adjustable Aeromotive I need to install. BTW, I forgot to mention, the car has Ford 19lb injectors in a custom made rail. I've put over 10k miles on this setup, so I doubt it's the injectors. Anything else I should look for? The car has been pretty trouble free since I've had it. Quote Link to comment Share on other sites More sharing options...
NewZed Posted November 30, 2015 Share Posted November 30, 2015 Pretty sure fuel pressure was in the mid 40s psi during this whole ordeal, but I'll definitely take a look at the fpr. I'm still using the stock one, but I've got an adjustable Aeromotive I need to install. BTW, I forgot to mention, the car has Ford 19lb injectors in a custom made rail. I've put over 10k miles on this setup, so I doubt it's the injectors. Anything else I should look for? The car has been pretty trouble free since I've had it. 19 lb injectors are over-spec. on flow. Mid-40's pressure is over-spec (way) on pressure. You should be running way rich from the beginning. What else did you forget to mention? Are you even using the stock ECU? Has the AFM been "adjusted" to compensate for the extra fuel the out-of-spec. conditions cause? Maybe the cog spring came loose and the vane is free to move. Quote Link to comment Share on other sites More sharing options...
Serban Posted November 30, 2015 Author Share Posted November 30, 2015 I know the injectors are a little bigger than stock. The guy who made the rail for me tried to get something close to the original ones, I guess that's as close as he could find? I'll double check the fuel pressure if I can get the car running long enough. The AFM was adjusted as per the atlanticz instructions to lean it out a bit. Full throttle the AFR is in the low to mid 13s, however, idle is very lean (when running "properly" of course). ECU is stock. I'll pull the AFM and inspect it to make sure nothing came loose in there. Quote Link to comment Share on other sites More sharing options...
NewZed Posted November 30, 2015 Share Posted November 30, 2015 Just check the simple reasons for excess fuel first. Check the vacuum hose to the FPR for raw fuel (blown diaphragm). Excess fuel pressure (the stock FPR is 36.3 psi). Leaking injector. Etc. ECU's tend to short the injector circuit open and flood the engine. Could be the ECU. Is the description below with the ECU unplugged? That would be odd since there should be no injector pulses. Holding the vane closed leans the mixture but also chokes air flow. It should also kill power to the fuel pump since the fuel pump contact will open with the vane closed (as the factory set things up - yours might be modified). You might spend some time in the Engine Fuel chapter looking at how fuel is supplied through the injectors, what the ECU uses to richen the base pulse, what the AFM does, etc. " I had my brother in law hold the wiper on the AFM clockwise, leaning out the mixture, and the car started and stayed running as long as he held it, once he let go, it would immediately run so rich, it floods out. " Quote Link to comment Share on other sites More sharing options...
Serban Posted November 30, 2015 Author Share Posted November 30, 2015 I was just browsing through the Engine Fuel chapter, I'll take a look at it a little more tonight. I'll report back with results as I have time to work on the car. Thanks for guiding me in the right direction in trying to hunt down the culprit. I may start pointing fingers at the ECU though. As I mentioned once I unplugged it, and plugged it back in, the problem would resolve itself, but now its not. Quote Link to comment Share on other sites More sharing options...
Serban Posted December 1, 2015 Author Share Posted December 1, 2015 Tried to start the car and it stayed on and idled fine, didn't flood out. Not sure what the deal is, but I'm leaning toward ecu. Fuel pressure with the vacuum line on was at 31psi. Quote Link to comment Share on other sites More sharing options...
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