3vzfe won't start! Help!!!

Davidss · 11-20-2008, 04:40 PM

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:

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...

Davidss · 11-21-2008, 01:52 AM

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.

Davidss · 11-21-2008, 11:53 PM

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...

conor · 11-23-2008, 05:22 PM

Timing off? Fuel injectors not being pulsed? Massive intake leak?

Davidss · 11-25-2008, 02:06 AM

Found the problem... The timing belt was almost gone. Put a new one on today and it started right up!

11-20-2008, 04:40 PM	#1 (permalink)
Davidss No Skills Join Date: May 2006 Posts: 36 Thanks: 0 Thanked 1 Time in 1 Post iTrader Rating: (0/0% )	3vzfe won't start! Help!!! 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: 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...

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11-21-2008, 01:52 AM	#2 (permalink)
Davidss No Skills Join Date: May 2006 Posts: 36 Thanks: 0 Thanked 1 Time in 1 Post iTrader Rating: (0/0% )	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.

11-21-2008, 11:53 PM	#3 (permalink)
Davidss No Skills Join Date: May 2006 Posts: 36 Thanks: 0 Thanked 1 Time in 1 Post iTrader Rating: (0/0% )	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...

11-23-2008, 05:22 PM	#4 (permalink)
conor Dead From Bad Intentions Join Date: Feb 2005 Location: Roseville, CA Posts: 858 Thanks: 19 Thanked 22 Times in 21 Posts Blog Entries: 2 My Google Map iTrader Rating: (1/100% )	Timing off? Fuel injectors not being pulsed? Massive intake leak?

11-25-2008, 02:06 AM	#5 (permalink)
Davidss No Skills Join Date: May 2006 Posts: 36 Thanks: 0 Thanked 1 Time in 1 Post iTrader Rating: (0/0% )	Found the problem... The timing belt was almost gone. Put a new one on today and it started right up!