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Moderator, l337 M0d3r4t0r
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Discussion Starter · #1 ·
I have a very strange issue, on my way back home driving form the dyno I was idling for about 10 min at the MC D drive thru, and my car just died. I though no big deal I'll start it again and it fired right up... But after a few seconds it coughed and died. Then every time i started the car as long as I held my foot on the accel the car would be fine but the moment I pull the gas the car dies even in gear. I have to let the RPM go to 0 then bump start it or manually start it again and it will go again until i let off the gas...

Wtf?

I am throwing a code 31 i believe A/F but my a/f is normal while i accelrate? I'll try my other map sensor but i guess we'll have to see...

Any ideas?
 

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Supras are never 'done'
1989 Toyota Supra
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601 Posts
FPR maybe? It doesn't sound like a typical MAP failure.
 

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Not so boring anymore
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Sounds like a dead isc...

remove a few vac line and see if the car will run with 0 throttle.. if so its a dead isc..
 

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Not sure if this is related but the other night mine did soemthing crazy too. I was cruising along and the car just "hickup'd" for a split sec almost like it was about to die but then went back to normal. Never happened again tho. Zazzn -- did your car doing the same thing and then just start cutting off? Or did it just start cutting off out the blue?
 

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Not so boring anymore
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881JZ said:
Not sure if this is related but the other night mine did soemthing crazy too. I was cruising along and the car just "hickup'd" for a split sec almost like it was about to die but then went back to normal. Never happened again tho. Zazzn -- did your car doing the same thing and then just start cutting off? Or did it just start cutting off out the blue?
mine has done that every once in a while.. the tach falls when it does it(not just like a miss), im assuming my ignitor is on its way out..
 

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Moderator, l337 M0d3r4t0r
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Discussion Starter · #6 ·
yeah I've had the car stumble and thorw a code 14 but I think thats more because of the two step... If I use the two step i get a code 14...

Anyways, i dont know it's cold now so i'll start the car again if I don't hear the ISC then i know for sure.

Sucks... Where do ppl get ISC's from for 1jz? are they the same as 2j?
 

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rip supra, new car soon
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gahh, i'm having the same problem with mine... I just got the swap done and the first few days no problem, now if i let it idle it bumps around until it dies. WTF!!!!
 

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*SNICKER SNICKER*
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tissimo said:
mine has done that every once in a while.. the tach falls when it does it(not just like a miss), im assuming my ignitor is on its way out..
Mine was doing that for awhile. I think I know what was causing mine (mine at one point was doing it so bad it was throwing code 14 or 24). which ever one is the IGT signal...

Where the harness was extended, something is not right at the splice points I am 99% sure on mine. I plan on just pulling 6 new wires thru the firewall right to the ignitor on mine from the ECU here soon. I know for me this will make that symptom go away. (Mine has stalled 3 times since the swap, and a few times missed to the point I saw the tach drop too).
 

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kaizen Motorsports
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suprasmakemesmile said:
gahh, i'm having the same problem with mine... I just got the swap done and the first few days no problem, now if i let it idle it bumps around until it dies. WTF!!!!

That's what happens when you dont let me do it for you! :doh:
 

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Moderator, l337 M0d3r4t0r
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Discussion Starter · #10 ·
going to be trying a diffrent map today.

Anyways, when the car stops responsing i can go WOT while still rolling at say 3000 RPM in gear and nothing happens. Not until i let the rpm go to 0 then engage the clutch to bump start it again.
 

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did you make any changes at low throttle a/f% on the dyno? If it's running lean the stock o2 will make it stumble and cut off.(I did this on purpose with a wideband to see if my o2 was working and that's what happened; it was working!).
 

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Moderator, l337 M0d3r4t0r
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Discussion Starter · #12 ·
it's not that the car stumbles at all...

it literally shuts off... almost like i turn the key off.... So i'm in gear at 4k then let off the gas, then when i press the gas again (still in gear at 3k now) it doesn't go anywhere. I have to put the clutch in let the RPM drop to 0 then bump start it and the injectors start spraying again.
 

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its the cams... lol

you can run the car w/o an ISC. you set the idle with the set screw on the throttle plate. works like a charm. actually some 1js ive seen around here bypass the ISC completely this way. you only really need it when you run A/C. other than that you can get rock solid idle manually adjusting it.

later
 

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Not so boring anymore
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check the wiring.. im going to say some wire on the ignition is grounding out and causing it to die.. happaned to my honda after i pulled the vafc.. wires were exposed and grounded out (rpm wire) caused rpm signal code and killed the car..
 

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that twin 2jz guy
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i was gonna bet on ur isc too.. isc.. idle speed control vavle... it controls ur idle... and if u are stepping on gas it should keep it alive, if ur drops low enough it will die.. i would start of that.. also since ur throwing code 31 .. (were u running a fcd or bcc. or anything off ur stock computer)....i believe ur have to go back and check ur map sensor wires at ur ecu..
 

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Moderator, l337 M0d3r4t0r
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Discussion Starter · #16 ·
It's fuel pump... Started the car today and went ot the engine bay, tried to rev it and FP went to like 5-10 PSI then the car would die and just before it did FP jumped back to 40.

Stupid walbro.
 

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JZA is best f**k the rest
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ZaZZn said:
It's fuel pump... Started the car today and went ot the engine bay, tried to rev it and FP went to like 5-10 PSI then the car would die and just before it did FP jumped back to 40.

Stupid walbro.
My car is doing this exact same thing, I hope my brand new walbro isnt shitting out on me also.
 

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Supras are never 'done'
1989 Toyota Supra
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601 Posts
Is there a reason you believe it's the pump itself? How about the filter or the pressure regulator?
 

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I am having similar sympton's, but mine only happened after I installed my Greddy SCC? It dies on me everyday. WTF? It really is starting to get old. Anyone?
 

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Moderator, l337 M0d3r4t0r
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Discussion Starter · #20 ·
mobes said:
Is there a reason you believe it's the pump itself? How about the filter or the pressure regulator?

It could be the filter, I ran almost 80% xylene, before I went to the dyno because I just filled up and hadn't got to the pump to put in the 94 yet. So i could have dammaged the filter, but it's unlikely since it's paper... It sounds like I hear the pump actually shut off then turn back on just after the car dies... I see the prssure go form 40 down to 0 when it dies then back to 40.

I'm fairly sure it's the pump.

We'll see since I have a new one here if I replace it and it's not that... well then all that work for nothing.
 
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