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View Full Version : 3vzfe won't start! Help!!!



Davidss
20-11-2008, 21:50
So I'm finishing up on a 3vzfe swap, the motor is going in a turbo mr2 chassis. The motor is in and wired up but it will not start. I have spark, I can hear the fuel pump running, I have compression, and it will start and run rough if I spray starting fluid into the intake. It will not start or continue running on it's own.

So now I'm going through the service hints in the bgb and I have a few things that do not look right:
http://www.mouseattack.org/pics/mr2/v6/diagram.jpg

a) This is VC which is supposed to be 5v power to the afm and tps. This is also where you tap into for 5v power to trick the speed sensor in on the ecu (which I have now disconnected to remove any possible problems). I AM NOT getting 5v here, I AM getting 12 volts. This is not due to a short in the wiring, with the ecu plug disconnected I am getting 12v right at the ecu. I tried a different ecu and afm yesterday and got the same results, 12v right at the ecu.

b) This is VS which is the afm signal return to the ecu. You are supposed to get around 5v with the engine off and ignition on and the voltage goes down as the afm door opens. I'm getting 12v with the engine off and the voltage drops when the door opens.

c) This is THA which I'm pretty sure is the air temp sensor in the afm return signal to the ecu. You are supposed to get around 1-3v depending on the temperature. I'm getting almost 10v.

d) This is VTA which is the TPS return signal to the ECU. You are supposed to get between 0 and 5 volts depending on throttle location. I am getting a sweep between 8 and 11 volts.

e) This is IDL which I think is either a WOT or idle switch. You are supposed to get 12v with the throttle open and 0v with it closed. I am getting 12v all the time.

Note on E - Looking at the diagram I'm not quite sure how IDL can ever be more than 5v? But the BGB says it should be 12v? Where is this voltage coming from? Could there be a mistake in the manual?

f) This is F which is a wire from the ECU to the igniter (I don't know how this part works). With the ignition on and the engine off it is supposed to be around 5 volts. I am getting around 2 volts but if I disconnect the igniter then I get 12v. The car is getting spark so I think everything is ok here but I'm not sure...

brianbooth
20-11-2008, 22:36
Pull the fuel line and make sure you really have pressure. Better to get that out of the way before digging through the wiring too much :)

Davidss
20-11-2008, 23:43
Pull the fuel line and make sure you really have pressure. Better to get that out of the way before digging through the wiring too much :)
I'll check that tommorow.

If anyone has a running 3vzfe if you could check your voltage on pin 1 of the second plug (should be light blue/red) I would REALLY appreciate it!

Davidss
21-11-2008, 06:52
So I went up tonight and tried a few more things. Now the ecu is putting out 5v correctly so I would say that A B C and D are solved. But E the tps idle switch is not working. I'm going to try readjusting the TPS next.

Now the car almost starts. But I noticed today that the VSV for fuel pressure up is broken (one of the nipples is broken off). However I seriously doubt this would cause the car not to start. Any other opinions? I tried it with both ambient and manifold vaccum to the fpr with no change.

Paul Woods
21-11-2008, 07:15
with it being an ex turbo did you bridge the wiring that used to go to the turbo fuel pump relay in the engine bay? bridge the two blue/black stripe wires together if not.

did you follow my wiring guide?

GaryA
21-11-2008, 17:53
Oh yeah that had me stumped for a couple of hours until i noticed the resistor pack sitting by my monitor , talk about :doh:

Davidss
22-11-2008, 05:02
Update- I put on a new rotor and it sounded a little better. I tried rotating the distributor and it sounded a little better. I tried to put the distributor in backwards (180 degrees off) thinking maybe that was the problem but I couldn't get the distributor to go in that way. Next I removed the intake manifold to check the compression and quit for the night.

PaulWoods- First of all thanks for your wiring guide it has been a great resource. If you ever want to swap a chevy v8 into a 240sx I would be glad to help with any advice you need (www.mouseattack.org). Part of the problem with this car is that it was an abandoned project. The previous owner used your wiring guide but didn't get very far. I went back through it and corrected all of the problems. It easier to start from scratch then to fix someone elses mistakes.

My car appears to be using the original turbo fuel pump relay but there is no fuel pump resistor plugged in (I do see the plug for it). The fuel pump does kick on both from the starter and when the afm door cracks open. Looking at the diagram I don't understand what the fuel pump resistor does? Is it even necessary? Do I need the resistor to make the fuel pump run at 100%?

Wombat- Are you talking about the fuel pump resistor or the fuel injector resistor pack? Because I do not see a fuel injector resistor pack on the 3vzfe wiring diagram. Does the 3xzfe even have a fuel injector resistor pack?

Paul Woods
22-11-2008, 08:25
you don't need the fuel pump resistor,that is for the turbo models so that the pump can run both a high and low speed mode,the resistor is for an 8v low speed mode.

With the v6 we bypass this on the turbo models,all you need to do is join the blue/black wires together at the fuel pump relay and also make sure the COR is wired up correctly.... which it all sounds like it is.

Davidss
25-11-2008, 07:06
Found the problem... The timing belt was almost gone. Put a new one on today and it started right up!

Paul Woods
25-11-2008, 07:08
doh! glad its sorted :thumbsup: