Very odd problem with my 1jz!

[Highlex]

Hey guys, two weeks ago when I was driving home from school my jza70 1jz 5-speed mk3 died, I cranked it over again and it started for 5 seconds, then died. I cranked it over again, ran for 3 seconds, then died. Then I cranked again and it kept cranking.

I opened up my ecu and found a melted capacitor, I sent it away to driftmotion for his ecu repair service, the fixed ecu came back today and I plugged it in, the car started and ran for a two minutes, then died. I cranked it again, ran for one minute, then died.

Im thinking that the ecu was not the problem and the car just ran for two minutes because I let it sit for a full week while waiting for my ecu...


So basically the longer period of time I let the car sit for, the longer it will run / idle for. If I wait a full day before cranking the car over again the car will run for a minute, but if I tried every hour cranking it over it only runs for several seconds.

I took off the gas cap and it de-pressuized as normal... also I can hear the fuel pump running, so thats good.

What do you think it is? Where can I start diagnosing... THANKS!

 

[hvyman]

You could start with check engine codes.

 

[87supraguy]

vaccum leak/bad map sensor? just a guess

 

[Highlex]

Tomorrow at lunch im going to check the codes and see what they say, im also going to hook up a fuel pressure gauge at the fuel rail and see what that reads.

Anyone else got an idea? What are the symptoms of a bad map sensor

 

[te72]

Try holding your gas just a bit when you're starting it up. My ISCV is picky and likes to stick closed sometimes when it's cold, and will do some rather similar things. If it is your ISCV there should be a set screw that you can adjust to the left of the throttle body to keep your throttle cracked just enough for it to idle. You might also check your TPS... Mine was broken (the ceramic on the inside) during shipping.

 

[Highlex]

All I got was Code 14.

Try holding your gas just a bit when you're starting it up. My ISCV is picky and likes to stick closed sometimes when it's cold, and will do some rather similar things. If it is your ISCV there should be a set screw that you can adjust to the left of the throttle body to keep your throttle cracked just enough for it to idle. You might also check your TPS... Mine was broken (the ceramic on the inside) during shipping.

The first part of your advice was right, it did start when I held the gas peddle down abit. The car wouldn't idle untill we adjusted the idle screw and that kept it idling at 1000.

When I took it for a drive it drove good untill I floor'd it. Then it cut out violently like fuel cut at 4500 rpm or so, it cuts out violently everytime and sometimes it will even stall and then the car won't start for a few minutes. Could the fuel pump ecu / relay be to hot and not working? Once it cools down it drives fine untill the peddle is floored and the boost starts to kick in then it cuts out again.

Don't these cars have a 2-speed flowing fuel pump? Could it be that the fuel pump can't kick into higher flow mode?
What is the pressure supposed to be at the fuel rail? How do you force the fuel pump into high flow mode?

Jump B+ FP? What does this do.

Thx

 

[Clint]

Is your 1jz in a MKII or MKIII? The only things that come to mind when reading your description is A) bad map sensor or B) bad fuel pump relay.

 

[Bigzavs]

your ecu just flat out took a dump on you, code 14 is the ignition circuit, and if aaron repaired the caps, then its just toast

a mine's ecu i had did the same thing to me

 

[Highlex]

your ecu just flat out took a dump on you, code 14 is the ignition circuit, and if aaron repaired the caps, then its just toast

a mine's ecu i had did the same thing to me

You think so? The car still drives normally though untill I floor it. I think its the fuel pump relay, im not sure where to get a used one in canada other than here.

Its a jza70, 1jz mk3 rhd

 

[te72]

Something to check on, spark plug gap. Mine was breaking up under boost around 4000 or so, until I gapped the plugs around .28. Haven't had the problem since. Although I didn't have that code 14 problem, but it never hurts to have properly gapped plugs does it?

 

[Highlex]

Im going to try and read fuel pressure at the rail, what is the fuel pressure supposed to be? Is there a way to test the fuel pressure when the fuel pump is in low-flow mode or high-flow mode?

 

[JPsToyota]

You are not hitting boost cut, right? Does your CEL light work and does it light up when you get this under boost problem?

 

[Highlex]

You are not hitting boost cut, right? Does your CEL light work and does it light up when you get this under boost problem?

My CEL does not come on when I experiance this cut out, but my CEL does work. I have code 14. Im thinking the fuel pump ecu or ignitor could be the problem?

The car will not idle unless the idle is set higher (above 700rpm) if it reaches 500rpm, it will die. Could it be the fuel pump?

 

[92TealSupra]

Sounds like your ECU could still have an issue?? Any friends with a spare?

 

[Highlex]

Sounds like your ECU could still have an issue?? Any friends with a spare?

Possible...

Im going to have to ask around, I don't think anyone has a 1jz ecu around here... Manitoba Sucks

 

[Highlex]

How can I test my MAP sensor? Do you think this could be my issue.

Sometimes the car does not start without giving it some throttle, it the idle gets to low (600) it will die... and if I put the peddle to the floor and the revs start to climb it will cut out and die, and wont start again untill it cools down.

 

[86_sports_1jz]

How can I test my MAP sensor? Do you think this could be my issue.

Sometimes the car does not start without giving it some throttle, it the idle gets to low (600) it will die... and if I put the peddle to the floor and the revs start to climb it will cut out and die, and wont start again untill it cools down.

i have a similar problem that i never figured out... wheres the fuel pump relay and do you have a wideband? when your car cuts out is your car going lean 15+ air fuel raitos? to test your map you can try unplugging it while the car is running to see if that makes a difference