need help 1jz won't run

Old School

New Member
Apr 26, 2011
54
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0
Minnesota
So I got a Map Sensor and plugged it in. No more codes being thrown now, but it does what it did before, turns over, pops an couple of times, but no run. I am checking the wire colors, since they are different between the map sensor connectors old and new. Don't think that's going to be the issue. Any ideas?
Thanks

---------- Post added at 06:57 PM ---------- Previous post was at 06:54 PM ----------

I can hear the fuel pump working, so gas seems to be present.
 

Old School

New Member
Apr 26, 2011
54
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0
Minnesota
Well I made some progress. By pulling the intercooler tubing on the intake and spraying gas in by hand, it runs. I can hear the fuel pump, but don't know if the injectors are clogged or not getting what they need to operate. Easiest way to verify??
 

Old School

New Member
Apr 26, 2011
54
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0
Minnesota
I checked for voltage at the injectors, and it is present. My thoughts right now are that there is not actually fuel in the fuel rail, or the injectors are not getting the proper signal to control flow of gas. When I was spraying in the gas by hand, the throttle position change made absolutely no difference. We do have a new TPS unit, as the old one was broken in shipping.
 

Old School

New Member
Apr 26, 2011
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Minnesota
I adjusted the TPS and the car runs (poorly), but only if you constantly pump the throttle. If you hold it down, steady, or idle, it dies. Anyone have any experience with something similar?
Thanks
 

Old School

New Member
Apr 26, 2011
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Minnesota
I'm kinda stuck here on the troubleshooting (trying to find something out of spec.) Does anyone know what the voltages are supposed to be at the TPS wires when the key is on? (not running). I should have the fuel pressure measured today. The engine idles OK, but the second it goes off idle, it stops unless it is continually pumped, at which time it runs very poorly.
 

Old School

New Member
Apr 26, 2011
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Minnesota
Just wanted to let anyone interested know what I came up with. Once I calibrated the TPS, I could get the car to start, Idle, and eventually run very poorly if I kept moving the throttle. Ended up changing out the fuel pump and filter which I was going to do anyway, but it didn't help much. Went looking for some good troubleshooting work arounds, as everything I measured kept looking good. It just so happens if you want to check out if the MAP sensor is bad (shouldn't have been, as I just got it), all you have to do is unplug it electrically. Presto! The car runs like it should. Just have to get a MAP sensor that actually works. Thanks for all the input earlier folks.
 

Old School

New Member
Apr 26, 2011
54
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0
Minnesota
As a follow up issue, the 1JZ would run fine up to about 3K RPM and then backfire everytime. After doing some research, it seems the NSW and STA inputs on the Soarer ECU need to be grounded (this is an automatic ECU that went into our manual setup). Once that was done, the issue went away and it runs great.
 

f00g00

Supramania Contributor
Jul 2, 2007
586
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16
Kuwait
I looked at the schematic and yes they are gounded, inside the ECU after going through a diode and then the signal dissapears. If you grounded them before the ECU then its two less inputs, the nuetral for auto (for manual its a switch made when depressing the clutch pedal, and the starter (STA) input. Im not sure what effect if any you will have without the STA signal, but don't forget to hold in the clutch when starting or if its in gear it will lurch.
The JZA70 ecu is differnt, it needs the signal for the circuit open relay.
Further research shows that the STA input is needed for injector duration during start, if the signal is missing I would think you would have a hard starter when cold.
 
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