1999 3RZ Taco- No Start,will crank

Hey there TW, found me a 99 3RZ 4x4 taco for 2k in no start condition…and i went for it, found a FSM (kinda) and started trouble shooting and i have come to a stand still since my knowledge only goes so far when it comes to mechanics. So here is everything i have done so far….

-Replaced Battery(Old one looked like it came out of a lake)

-Replaced ground strap that goes from batt to fender since it was missing

-Replaced plugs with oem denso plugs

-Tested ECU power supply circuit and that passed with 12.5v

-Tested crankshaft pos sensor with multimeter according to fsm and it was with in values

-Checked all micro fuses

-Checked coils according to fsm and they were good

The only thing thats left for me to check is camshaft pos sensor and compression test

Also i need to repair tps sensor that i found a wire broken off twist repaired it for now but i doubt that would cause a no start..would it?

my only concern is that it will need valve cover gasket since i found traces of oil in plug 4 and a oil pan gasket since only the pan is covered in oil

 

you need to determine if the no start is fuel or spark related. A quick squirt of starting fluid in the vacuum hose that goes to the brake booster will tell you if she is lacking fuel. anything more than a quick squirt and you can do damage to the motor.

take the connector off the spark plug and ground the spark plug and crank it over to see if you have spark.

 

Seems she is lacking fuel put some fluid in the vaccine hose and she nearly started. Disconnected the return line and fuel comes out with cranking...but I don't know if it's enough pressure for the injectors

 

the fuel pressure regulator bleeds pressure off so using it as a test to determine if there is sufficient pressure wont work. can you hear/feel if the injectors are clicking?

 

Years ago, I had to replace the ignition switch for this problem. Don’t know but good luck!

 

Is there a check engine light? Go to auto zone and retrieve codes. Many things can tell the computer to not allow the engine to run.

 

Injectors are not clicking...none of them are I doubt all of them went bad at once right?

I have a bluedriver scanner and only codes I get are for maf sensor

 

Does the horn work? I think IGN is the same fuse or something

 

Horn is working

 

ok… we are making progress, with a test light check if there is voltage on one side of the injector connector. There should be battery voltage at one side of each connector when the key is in the run position. If not look in the fuse boxes for open fuses. There is a fuse box under the hood and one by your left knee. I don have access to my manuals at this moment otherwise I would tell you exactly which fuses to check. Someone with access to that can chime in and save you some time.

if there is power then the problem is with the “signaling” side of the system. The box (PCM) that triggers the injectors to fire and spark plugs to spark requires a signal from the crankshaft and the camshaft. It is at this point my recommendation is that you get a professional involved. Yes you can put a crankshaft and camshaft position sensor in and you might get lucky… if you don’t, where do you stop throwing parts at it?

 

There is voltage in the harness 11.48v on one side of the connector and on the other is only about .03v...battery is about 11.90. although while removing the throttle body I found two broken connectors one for the IAC (one wire is completely broken of the harness) and the camshaft pos sensor

 

Is it possible to replace the whole harness? Or can these connectors be replaced?

How easy is it to find a engine harness?

 

I know the 5VZ will start without a cam signal but not without a crank signal - not sure about the 3RZ. When you're cranking do you see the RPM needle bouncing a little? If not it could indicate something going on with the crank signal.

 

Crank position sensor broken wire will cause the 3rz to turn over but not start. Found this out when rodents chewed mine.

 

fantastic… you found something. is it IT, don’t know, wont know until these connections are repaired. I might have the connectors… I wont know until I get back home in 3 weeks due to…

 

Unfortunately mine does not have a tach....going to see if I can find one with a tach to replace this one at a later time

 

Il be going to the junk yard I saw they have a 95 taco there and see if I can source the connectors I need that way..

Enjoy your vacation!!

 

You don't need a tach, you can check the RPM with a scan tool as well. If it's calculating the RPM then it's receiving the crankshaft position signal and it's likely fine unless the tone ring is damaged. If it were me I'd repair all the wiring before going further then go a little deeper with checking if you're receiving ANY injector pulse whatsoever. How did you check for injector pulse if your vehicle does not run? If you tried to listen (or feel) for clicking at the injector while someone is cranking that's probably not going to do you much good with all the background noise and vibration from the starter. What you can do is: with key on, engine off check for battery voltage at the black with red stripe wire. This is the common power feed to all the injectors. The ECM controls the switching on the ground side. If power is good use a noid light plugged into the injector connector and see if you're getting a pulse signal. If no power at the black/red wire then you have either a blown fuse or open circuit in your power feed. If no pulse AND no RPM I'd be looking at the crankshaft position sensor, but if you're getting some pulses it could be a damaged tone ring at the crank sprocket throwing off timing. If there were no crank signal whatsoever you *should* be getting a code for that but then again strange things happen sometimes.

 

You can buy just about any connector online and re-pin it. You could also just hard wire it. Just makes replacing the parts a little more difficult in the future.

 

Does anyone have a wiring diagram...i forgot to take a picture of the camshaft harness wires and I'm trying to repin the new connector on...