1994 Toyota Pickup RWD 22re base, 212k miles, sitting for around 2-3 years, has had idle issues for awhile. Bought it from a co-worker trying to clear out his property of project cars.

• New battery
• New fuel pump
• New fuel filter
• Fresh gas, oil change, antifreeze flush and replace.
• Truck runs for a brief while, then stalls out. Fuel pump was working as it should after replacement
• New fuel injectors, New sparks plugs, nothing changes. Fuel pump now only kicks on when I do a Fp to B+ bypass

Truck turns over, doesn't start. Spray starter fluid down the intake manifold it will start then stall out once you stop putting in start fluid (no fuel injecting into cylinder clearly). Fuel pump doesn't kick on unless I do Fp to B+ bypass at either the diagnostic port or at the circuit open relay. I replaced fuel pump and filter and it drove around the neighborhood for maybe 30 minutes before a rough idle at a light on a hill and proceeded to not go more than 5 mph after that. Once I limped back to my house and parked it, the truck was back to its original state of turning over but not starting. My thought was replacing the pump (which definitely needed replacement) and the fuel filter likely cleared up whatever fuel blockage was in in the line, then after driving it some, something else gummed up the lines.

It seems like there is a fuel delivery issue related to electronics at this point. When I have the Fp to B+ bypass going, fuel shoots out the main fuel line going from the tank into the filter. There is no fuel coming out of the cold start injector. If it was just a bad cold start injector, shouldn’t the fuel injectors take over once I spray starter fluid?

Thought I would get others perspectives before doing much more. I do have a new circuit opening relay on the way. Haven't had a multimeter to have done much in terms of electric troubleshooting but will have access to one soon. Looked through most of the threads describing similar situations for insight.

 

It's been a long time but I think the pump kicks on for a few seconds when you start it. The AFM senses air flow and keeps it running. Have you checked it out? Any CEL's?

I just sold a 1990 that sat abandoned since 2011. I pulled the tank and flushed it. New pump and screen. Before I put the new filter on I squirted carb cleaner into the open fuel lines and blew it through the system with compressed air until it came out clean just past the regulator at the return line near the firewall. I also did the same to the supply line from the tank, the return to tank and the vent. The vent was plugged. I put fresh fuel in it and jumped the FP to Bat+ to prime it. Then it started right up and ran great. I got lucky I guess.

Good luck. I hope you figure it out. Let us know what you find.

 

Pump won't kick on with key in on position if the FP to Bat+ bypass isn't in place. Haven't done anything with AFM at this point, what would the approach be in diagnosing it? Vacuum lines all could be replaced, but none look to have any breaks in them.

Only been able to get it running the once, no CEL on the dash, that said the speedometer and FLS sensor on the dash don't work so I don't know how much faith I have in if it is/isn't sending a CEL. I haven't hooked it up to a scanner.

In hindsight, I probably should have spent some more effort in cleaning out the tank and lines when I pulled the bed off and the intake manifold. The original sender and filter were shot and pretty much falling apart as I pulled them out of the tank. I am hoping it is just one of the lines gummed up, but I can't say I have the electrical knowledge to be able to say why the fuel pump is no longer kicking on outside of the bypass, and the cold start injector is no longer working. My reading of one of the shop repair manuals led me to believe that the CSI was pulling gas in from the main line before it branches at the filter. Is there something within the ECU that would prevent a signal to the CSI and FP if it detected a misbalance of air flow to fuel because of a clogged line?

 

The circuit Opening relay comes into play with key on. Hopefully someone else more versed that I will chime in. I don't have my service manual anymore. No more 22RE's. Scroll down the posts a little ways. There is a similar situation posted a few weeks ago and somebody posted up troubleshooting procedures and links to the factory service manual.

The pump kicking on with the jumper at least tells you the pump circuit is ok. The key switch should close the COR and I believe the ECM and AFM keep the pump on. So something isn't telling the pump to turn on right from key on. COR?? Because if it was, it would start and the AFM would have air flowing through and tell it to stay on. Key on, pump should go on for so many seconds.(I don't remember how long) It should crank and start. Then since it has air flow and ECM knows it's running it keeps running. I don't "think" the cold start comes into play unless under a certain temp??

You do have the air intake tubing on?

The fuel filter is before everything. The fuel goes from the pump to the filter on the side of the block, then up to the fuel rail and the end of the fuel rail is the regulator and back to the tank. The cold start hard line just comes off the fuel rail. It's all after the filter. It's just a loop.

 

The COR has two halves. One half is energized when the key is turned to Start. You can check this by turning the key to start, but do not press the clutch, or the Clutch Cancel button. If the "start" half of the COR is functional, you'll hear the fuel pump running.
To check the other half of the COR, you can open the vane in the AFM, even slightly, and turn the key to the On position. If the "run" side of the COR is good, you'll hear the fuel pump running.

Never, ever drive the vehicle anywhere with the jumper in. It's bypassing the COR, which is a VERY important safety device. It shuts the fuel pump off if there's an accident, so you're not pumping gasoline out onto the ground, which is a pretty bad safety thing. If you have the jumper in, that safety feature is disabled, and you could very easily wind up with a big puddle of gasoline around you, evaporating like mad, so one little spark...

Does that explain it well enough?
Pat☺

 

Thanks for the "refresher" on the COR 2ToyGuy.

 

Finally got a new COR in the mail. Fuel pump still isn't kicking on unless I bypass COR, but now when I turn key to Start I am getting the "click" from the COR that I previously wasn't. Going to fiddle with the second half of the COR this afternoon and see if things are related to AFM

I am still a bit baffled by why there is no fuel coming out of the cold start injector when there is fuel coming through at least the inlet part of the fuel filter. I suppose if there was a blockage it would be either in the filter, in the line to the fuel rail, or in the fuel rail itself prior to where the cold start hard line shoots off the fuel rail

 

Missed the question here but yeah problems occur with and without intake tubing on.

 

No fuel pump activation with a new, known good COR is a sure indication of either a bad fuel pump, or wiring TO the fuel pump. The connections on the fuel pump hanger unit, where the fuel pump connects to the wiring feeding power to it, are a known problem area. ost especially the ground connection. It connects to the body/frame metal near the tank to provide ground for the fuel pump. This connection, as well as the one on the pump hanger, are prone to corrosion, causing a bad ground.

Easy enough to check to power, and ground, at the top of the fuel hanger to make sure your getting power, and ground, to the pump when you should. If the hot out of the COR is good, but the power at the hanger connection is bad, bad wiring somewhere along the line. If the hot is good, check the ground on the hanger to see if it's providing good connection. Either ohm it, or check the voltage using the hager's ground point as the ground for your meter. If the voltage is good at the hanger when using the body/frame metal, but no good with the pump hanger ground connection, bad ground to the hager.

Sorry, I go on too long.
I shut up now...
Pat

 

The detailed responses are what I am here for! This is my first foray into a project car. I know enough to know I know little.

Wouldn't the fact that the pump kicks on with Fp to B+ indicate the wiring of the fuel pump/fuel pump itself is fine?

 

SOME of it is good. If it runs properly with the jumper in, and the out put of the COR to the fuel pump is correct, BUT it doesn't run with just the COR power for it, then the wiring between the COR and where the jumper feeds in is bad.

IOW: There's a Y in the wiring to the fuel pump. On leg goes to the COR, one leg to the Fp pin of the test jack. Apparently, the leg from the COR is no good somewhere along it's route. Trick is to find just exactly where the Y is, then track the COR side, checking for pulled connector pins, rubbed wire insulation, etc. Alternatively, start at the COR, and check the voltage, with the key on and the vane of the AFM open a bit, it doesn't take much, and trace the wiring towards the fuel pump, checking the voltage as you go. Just exactly where, along the wiring's route, the Y is located, I'm not sure, but there has to be one somewhere. If there weren't the test jack would be colocated with the COR

Best method when checking a circuit, BTW, is to break it in half, and check it where the break is. IOW: Go 1/2 way from the COR to the fuel pump, and check to see if the voltage present at the COR is still present. If it is, go 1/2 way further along to the fuel pump, check it again. If it's not, go 1/2 way BACK towards the COR, and check it. It saves a lot of time, jumping 1/2 way along the circuit at a time.

Good luck!
Pat☺

 

Then pretty much everything else you did (replace battery, fuel pump, injectors, COR, ...) was a waste of time (and money). You have an electrical issue. You will never solve it with the parts cannon.

2toyguy's description of the starting circuit is correct (especially the part about not driving around with FP jumped to B+ !). Here's a more detailed diagnostic description: https://www.yotatech.com/forums/f116...-quits-312747/

WRT to the cold-start injector, you need to remember that every time you open a high-pressure fuel connection you must replace the pair of crush washers. It may not be leaking right now, but when it does it will be a very bad day. Instead, to verify fuel flow replace the fuel return line from the FPR with a 6mm (1/4") clear vinyl tubing to a suitable container. With the jumper, I get about 1/2 liter/min (there is no spec.) This will "test" for a blockage all the way from the fuel tank to the end of the rail. Since the return line is low-pressure, you don't worry about crush washers.

 

If you really, really want, you can pull the CSI out of the Throttle Body without removing it's fuel line, and put it into a container to catch any and all fuel that may come out of it. Once verifying that the CSI is good or bad, you can bolt it back onto the TB again. Really, only good for checking the CSI, without having to replace the crush washers.

The method Scope suggested for testing the fuel flow is really the best of all. If the amount of fuel that comes out of the return line when you turn the key on with the jumper in matches his spec (there isn't one in the FSM, but his is absolutely correct from experience), Then you can be assured that the fuel system up to that point is good. No blockage of the filter, pulsation damper, rail, etc etc.

Keep us up to date! Go to your local Harbor freight, or something similar, and pick up a multimeter. They're very inexpensive, and last forever, when treated correctly. It's also one of the best tools in your tool arsenal for trouble shooting a myriad of issues, many of which cannot be checked any other way. For ANYone that wants to do their own work on a vehicle, it's an essential tool.

Good luck to you!
Pat☺

 

Been a busy week, haven't spent as much time on this as I would like.

I've got a multimeter now and will get started on checking the electrical as you both outlined. I am wondering if it is fuel pump electrical connections, they were in rough shape when I changed things out there. Again in hindsight I should have spent more time there.

WRT the fuel filter and CSI. With a jumper in, I am getting fuel out of the inlet side of the fuel filter, but nothing out of the CSI. Need to grab some more crush washers in order to check about the outlet side, but assuming I am getting fuel to that point, would that not point to some blockage between there and the CSI? Or should would answers to the electrical questions help nail things down.

 

Did a couple things tonight. Checked B+ and Fp on multimeter per the post you linked. B+ is at 11.64 V and Fp is at 1.0/1.1 ohm.

Haven't pulled the return line off the FPR, but flow out of the outlet of the fuel filter is around ~0.1 - 0.2 liters/min (with bypass in). Will try from the return line tomorrow.

Started poking around the VAP, Fp kicks on without having a bypass in place with key on and MAF/VAP vane even slightly open.

Seems like I need to get out the checking the return line next.

 

Fp is 1.1 ohms to where? Ground? Again, be cautious of ohming anything. Make certain both battery leads are off. Do NOT try ohming anything that even could possibly have the slightest voltage on it.

The volume out of the fuel filter is a good test of the fuel pump and filter, at least. If it's that low a volume, and that IS low, since we're looking to get 0.5 L/min, you might want to check at the input to the fuel filter. If it's good there, and bad at the output, bad fuel filter. If it's bad at the input, bad fuel pump.
From your description, I would absolutely check the voltage at the fuel pump by pulling it out and reading it's positive input. If it's good at the contact on the fuel pump hanger's contact, but bad at the fuel pump, the contacts are probably corroded, and need to be cleaned up. If the voltage at the fuel pump is good, but low volume out of it, bad fuel pump. That could include the "sock" on the pumps intake being clogged up.

The fuel pump activating with the vane open, even slightly, tells you the COR Run side is working correctly. Now you need to verify the start side of the COR. Easy enough. Turn the key to start, but don't press the clutch, or the clutch start cancel button. You'll be able to hear the fuel pump run, if all is well.. The starter won't crank the engine over. If the fuel pump doesn't run, bad COR. It's kinda quiet, but you heard the fuel pump run with the vane open, so you should be able to hear it while turning the key.

Good luck!
Pat☺

 

Fp is 1.1 ohms to ground.

Volume out of the return line is about the same as what was coming out of the fuel filter outlet, 0.1 - 0.2 L/min.

Fuel pump doesn't run with key at start unless bypass is in. COR should be good, as it is brand new.

That said, I blew out the fuel lines as best I could with a can of compressed air (compressor bit the dust), and the engine is turning over again without starter fluid down the intake or the bypass in. Just immediately dies though, doesn't idle. With a bypass in and the accelerator pressed, engine turns over and will run so long as the accelerator is being pressed, BUT does start to make a loud popping/knocking near the MAF if you do that (I stopped after that occurred).

 

Ended up being 3 problems: 1. Blockage in the fuel system between fuel filter outlet and CSI/fuel rail; 2. Large fuel/air imbalance from multiple locations at the intake manifold that were not properly sealed; and 3. broken/rusted out wiring to the fuel pump, both on the hanger unit and outside the fuel tank.

Need to button a couple things up before getting it on the road, but should be good to go soon enough.

Thanks ya'll, I am sure I will be back with more questions in the future.