tarboxb

I have a 1994 Toyota Pickup with a 22RE. The engine will start great and run well for a few seconds and then stall. Often times the engine will barely run, just chugging along at like 150 RPM for 10 seconds or so and then totally quit. If I give it gas I can get it to climb to higher RPM for a bit but then again it suddenly stalls. I believe that the fuel injectors are not firing. With the cold start injector disconnected the vehicle will not run at all. It will run on starter fluid. I have connected a jumper between B+ and FP in the diagnostic connector and the fuel pump runs with the key to the on position. This problem also happened to me about 2 weeks ago and I took off and cleaned the ECU ground that connects to the plenum and after reconnecting it nice and tight, the vehicle fired right up and has been good, but the other day the problem started up again. It seems to happen when it is wet out. Thinking it could be the splices for the fuel injectors inside of the wiring harness, I disconnected everything and tried to snake the harness out of the plenum. After cutting open the entire harness inside the engine compartment, I can still not find the splices. The one thing that I did find, however is a broken wire. This wire comes out of the firewall as a thick green wire and the last 8 inches or so of it are black. The wire that the thick one connects to is much thinner than the thick green wire. I believe that I may have accidentally broken this wire trying to snake the harness out from under the plenum but I am not sure. I have tried to look at wiring diagrams and so far the only thing I have found is that this wire goes to the fuel pressure up valve but from my research it only seems that this engine has a fuel pressure regulator. Are they the same thing? I haven't tested the fuel pressure but I really doubt that that is the problem seeing as how when I cleaned the ground on the plenum the problem disappeared before. Does anyone have any idea what I should do? This is really frustrating and I really need to get the vehicle back and operational. I appreciate everyone's input and I am sorry for the massively long post. I hope we can figure this out guys. Thanks a lot.

tarboxb

So, I have found where the green wire goes at least. The wire goes to a connector that I did in fact rip the wire out of that is connected to a sensor located right by the fuel filter. Does anyone know what this sensor is by any chance? If anyone can help me figure out this problem it would be much appreciated.

tarboxb

Ok, so I looked it up and that sensor is the knock sensor.

toyota4x4907

Make sure all the vacuum hoses are connected going to And from the fuel pressure regulator and FPR VSV (blue, on top of the valve cover). Look up the routing diagrahm of the vacuum lines And make sure they are where they should be.
The sensor on the block near the fuel filter should be the knock sensor. I honestly can't remember if that can prevent it from starting.
Can you pull check engine light codes?

tarboxb

So I checked the vacuum lines and it appears that both the FPR and FPR VSV are hooked up correctly. That is actually something I forgot to mention though. This problem has happened in the past and I disconnected the vacuum hose connected the FPR VSV to the Gas Filter on the side of the plenum and got it to start with that hose disconnected, this has no effect on it now, however. Does this mean I have a bad FPR VSV? Also, I do not have a check engine light on, so doesn't that mean that I have no codes, or do some codes not trigger a check engine light?

tarboxb

I noticed that two wires just before the connector for the igniter are chafed. One of these is the IGf signal for the computer to fire the injectors, and the other is the IGt signal wire. I believe these are arcing out on each other and keeping the computer from getting the signals that they need. It is cold and wet outside so I am going to put off hooking the whole wiring harness back up and everything for another day, but I am confident that this is the problem. What does everyone else think?

tarboxb

Nope. I hooked the wiring harness back up, minus the wires that go toward the drivetrain and the o2 sensor, expecting that it would still run without these and the same thing is happening. It appears that the igniter wire was not at all fault, at least not entirely. I am pulling my hair out over this thing. Any other ideas?

tarboxb

Do those other sensors absolutely need to be hooked up for the vehicle to run at all? Oh, I also haven't fixed that knock sensor problem but still the vehicle runs fine if I put gas into the throttle body so the injectors are still not firing. From my understanding the knock sensor has nothing to do with injector firing.

tarboxb

Does anyone have any ideas about this problem. I still cannot figure it out. Can anyone help me. I would really appreciate it. Thank you guys!

Terrys87

iTrader: (1)

Not all problems will throw a code. I am not sure what the green wire is at this time. I will look and see it is the Knock Sensor later today. There are some sensors that the truck will run with not being hooked up. Knock Sensor is one of them. It wont keep the truck from running.

The splices/crimps are going to be about a foot in front of the #1 injector. Where the harness dips down from the front of the intake and attaches to the passenger inner fender. You will need to remove the protective covering and then the crimps are just covered with a piece of black tape.

I have had them to pass a resistance check and still not fire the injector. When you remove the harness protective cover, you will most likely find alot of grit, oil, water and such inside the cover. I cut out the crimps and solder the connections together.

Here is what all I have gone thru to check for Non Firing Injectors>>> https://www.yotatech.com/forums/f199...l#post51897320

tarboxb

Thank you for the response, Terrys87. I am sorry that I have not been able to get back to you. I have been busy the last few days and haven't been able to get to work on the truck. I found the splices, though there is only one. Both wires from pins 10 and 20 from the ecu conjoin and seperate into the four injector wires. This puzzles me. Anyhow, the splice looks very good with absolutely no visible corrosion. I connected an LED to the injector plugs and am getting light. Does this mean the injectors should fire? It is possible I simply do not have the power to run the injectors, correct? Does my problem sound like a fuel pump or are you convinced that it is indeed the injectors. Because of the fact that messing with the ground on the plenum solved my problem at one time, I feel like it is related to the injectors not firing, not the fuel pump though it has a factory fuel pump so that is totally possible. What about the fuel pressure regulator and fpr vsv? Like I said, I had a similar issue happening one time and disconnected the vacuum lines connected the gas filter on the back of the plenum allowed me to get the vehicle to start, however it ran with a quite high idle. Once it was running, I reconnected this lines and the problem went away. Does this mean one or both of these components is bad? I think I need to try and get my hands on a fuel pressure tester so I can rule all of that out. I don't know what is going on. This problem is truly peculier. I was so sure when I found the damaged wires going into the igniter plug that that was the problem. Do you think it is possible that those wires caused the igniter or ecu to become permanently damaged? I appreciate the help from yourself and anyone else who decides to contribute to this problem. It really means a lot. Thank you guys.

805yoda

Please tell me you have figured out the problem, I keep searching and searching for answers and nothing.... I'm pretty sure you have the same problem as I do...