I've been working on getting my 4runner to start right up smoothly for a month now and I need some advice before I drop alot of $ on her again. I believe it's got to be something in the fuel delivery. Over the past month I've replaced the fuel filter, cleaned the injectors, replaced the O2 sensor back to OEM(very expensive, didn't make a difference if anyone wants my old one), replaced the filter again, I thought the difference that changing it the first time made had faded away (all in my head). Now after reading through more of the literature and topics on this site I found the fuel pump issue in the cheap tricks section. It sounded alot like what my truck is doing, turning over 9-10 times before starting, then running roughly for 10 seconds with a little black smoke, even if the engine is still warm (only has to be off for 10-15 min.). So I did the suggested, I bypassed the fuel pump switch in the airflow meter and it didn't work. I've checked all my grounds and 4crawler suggested going through some of the harness around the intake for the injectors and checking for shorts. Everything seemed to be in order, but the description described in "cheap tricks" sounds too familiar. Do EFI fuel pumps still work partially when they are going bad? My truck runs smooth after the first 10 seconds, so the pump still pumps. Or could this be a relay or something. I just pulled the sending unit out of the tank to check the condition of the tank and the pickup screen and they're both clean. any suggestion about what I should blow my money on next would be much appreciated. I'm not sure if a relay could cause this sort of thing or not, and I'm not sure how a fuel pump goes bad. If I'm even looking in the right area.

One way to see if fuel pressure is a problem, put a fuel pressure gauge on and see what it says. I drilled and tapped the end cap of the fuel rail and soldered in a brass pipe thread elbow and screwed an electronic pressure sender into that, run to a gauge in the cab.

Another option is to check the voltage at the fuel pump (under load, while it is running) and see if it is getting good voltage or not. If the voltage drop is excessive, you may have bad wiring or relay that just can't supply full power to the pump or the pump itself is gummed up and making the motor work too hard.

Thank you for the quick reply, that's awesome. I didn't even think of trying a fuel pressure gauge. I'm going to try that out. The brass, is that a solder or what? What pressure should the fuel rail be getting? And does the location of the gounds make a difference? I know I got them all attached but they may not be on the original bolts. Would that make a difference?

I mean is it a brass solder or just regular solder and flux?

Just plain old plumbing solder, acid core. End cap on the fuel rail is steel, just grind off the chrome plating, put in the fitting and solder it in place. Only reason for the solder is that the steel is thin and I doubt you could get a good seal and you don't want that loosening up. Other option is to rig up an adapter under the cold start injector for a test gauge. Supposedly Napa has the fittings needed to do that. Stock pressure is in the 30-40 psi range, it varies depending on engine vacuum.

Sounds like some sort of thermo time switch issue? Im not sure if toyota uses a thermo time switch to determin cold start injector duty cycle or not? Maybe Roger would know?

This is just grasping at straws really but why dont you try disconnecting the electrical plug from the cold start injector and see if that makes a difference. You may also check the cold start injector for leakage under pressure too.

Just a thought... <img src="/forums/images/graemlins/confused.gif" alt="" />

Good idea I never thought of that, I was excited when I tried it, but it didn't work. Thanks for the advice though I'll grab any straw I can get now. Took my truck to Camelback Toyota here in Phoenix and paid $98/hour for them to tell me to put Denso plugs back in it and stick to well known gas staitions. I always give mine 91 though, so I was convinced they were full of something. Put the Denso's in anyways, does run a little better but didn't help my problem. Anyways, Iwas wondering if anybody knows if the banjo bolt on the fuel rail could cause something like this. I don't know how they go bad, I've only seen them leak when needing replacing. I'll take any advice anyone can give me. It's gotta be cheaper than what I've put into it recently.