18 replies to this topic

[jaime.g]

okay, so i recently used to have two check engine codes, 41 (tps) and 31(map). however i somehow managed to have them go away finally. however my 1jz is still not running right.


what i mean by not running right is that

A) dies a few seconds after starting up (goes to a quick idle then dies)
if i help the start up procedure by blipping large amounts of throttle the car is able to rev decently high withh random breakup however and after those short blips of throttle it will no longer respond to the throttle and die

i thought this issue was related to a tps sensor i had got off someone on a forum, however after messing withh the calibration procedure via mk4 fsm, the check engine light went away and now i have nowhere else to look.

things i've tried to fix this issue.
1) short pins fp and b+ thinking it maybe a fuel power problem
2) added about 3 gallons of new 93 octane gas (before that it was 87 2 year old sitting gas

that's all i can think of for now. it is stil on the stock fuel pump, however the 7m before that ran fine withh it.

any ideas would be great.

thanks


**edit: now that i think about it i'm leaning towards the fuel pump. guess i'l order that bad boy

[toycoma]

are you sure the fuel pump is on all the way?? i know the fuel pump will prime for start up and the motor will even run but will soon die if the pump is not fully on. so that would be a wiring issue most likely. but if you know for sure you have the fuel pump totally wired correctly, then I don't know.

MAARRRKKK!!!!!
or just pm him.

[jaime.g]

well supposedly if you jumper the pins fp(fuel pump) and b+(ignition power) in the diagnostic connector, it is supposed to ensure 12v to the fuel pump circuit.

i already tried this withh the same results, unless this is the wrong way to go abou t it.

[rayray]

could be your ecu. i tried everything, checking everything from fuel, spark, spark plugs, tps, tb. had the ecu checked and repaired and started up like a champ.

[driftaholic]

meter the voltage at the pump to be sure. also meter FP-REL and make sure it's functioning. I had to wire a relay for my fuel pump.

[jaime.g]

i've also checked the ecu about 7 months ago however on my friends jzx73 and ran fine.

so i know it couldn't be that, unless it has failed since then.

what is weird though is that if i unplug the map and tps it will idle for as long as i have the key on the on position (of course it will instantly die withh any throttle movement)

now i have had tps and map sensor codes before and over doing a few changes they have gone away. has anyone ever seen a bad sensor withhout a check engine code??

i have seen cars before idle well withh lack of fuel in the tank but the instant the throttle is touched it dies.

in this case i'm still leaning towards fuel pump. it will be a while when i'm able to order one though since funds are low and this is just a backburner project.

[brian]

check your fuel pump resistor box connection. you can just short the pins to run the pump at 12v all the time. the resistor box is on the passenger side strut tower.

when you first start the car, the ECU swithches the pump to 12v (bypassing the resistor) then after the start procedure it swithches the pump to lower voltage (using the resistor circuit), if the resistor is not plugged in or there is some other break in the circuit the pump will just die.

This situation has happened to pretty much everyone I know putting a 1JZ in a Cressida.

[jaime.g]

i ran out of time today to do any further testing. i will definitely do more metering of the pump like driftaholic mentioned.


having this car all the way across town sucks!!! especially withh these gas prices

[jaime.g]

check your fuel pump resistor box connection. you can just short the pins to run the pump at 12v all the time. the resistor box is on the passenger side strut tower.

when you first start the car, the ECU swithches the pump to 12v (bypassing the resistor) then after the start procedure it swithches the pump to lower voltage (using the resistor circuit), if the resistor is not plugged in or there is some other break in the circuit the pump will just die.

This situation has happened to pretty much everyone I know putting a 1JZ in a Cressida. Laughing

now that you have told me that, i remember reading about this in the toymods forum a long time ago and have completely forgotten about it.

i will definitely try that.!

[toycoma]

check your fuel pump resistor box connection. you can just short the pins to run the pump at 12v all the time. the resistor box is on the passenger side strut tower.

when you first start the car, the ECU swithches the pump to 12v (bypassing the resistor) then after the start procedure it swithches the pump to lower voltage (using the resistor circuit), if the resistor is not plugged in or there is some other break in the circuit the pump will just die.

This situation has happened to pretty much everyone I know putting a 1JZ in a Cressida.

that has to be why my car would not start either so we jumped out some wire withh its own power. good to know for my next car build.

[jaime.g]

looking back at an old video i made when i first got the car running, i can see the fp resistor sitting in the engine bay and i was able to clearly rev it withh hardly any issue even withhout ic piping hooked up.


and i definitely remember removing the fp resistor along withh the old 7m coil to clean up the engine bay somewhat. between that time and now

so yeah im almost positive this is my issue. man i cant wait to get back to work on the car

[aphxero]

Some random thoughts on this.

If you're using anything newer than an x81/a70 ecu the fp and d1 pins won't function properly. You have to go straight to the circuit opening relay.

And fwiw the FP resister doesn't do anything unless you swithch to it. This is a function of the ecu not the chassis. To bypass all nonsense go behind the glovebox, look for the big gray plug. In the corner of said plug is a solid green wire. Ground it!

The 12v side coil in the circ op (and subsequently the fp relay) will be swithched by the key. Basically the body harness now thinks there's a 7m AFM telling it "go full throttle" all the time. Remember they both share +b1 (efi relay output) as a source.

This all works because you have to ground the other side of the coil. The STA coil in the circ op bypasses this because there are actually 2 in there. The start signal is the hot side of the second coil. Stop cranking and fuel goes away.

If you have an x81/a70 ecu make sure you put fp from the ECU to the green wire I've just described. The green/red wire everyone loves so much is the low voltage side of FP relay in the cressida body DON'T USE IT!!!. That's the circuit you cut when you removed the resister which is a good idea anyway. I think the reason this trips people up is because this wiring scheme isn't typical for toyota. The corolla, supra, etc are the exact opposite (ie: the fp wire colors match up).

Dude if you were running the low voltage side (which I'm sure you were) then you just did yourself a favor withh this whole situation. You might not have lasted long withh a fuel pump running at 9v under boost.

Btw, you're essentially doing the diag box trick except the engine harness (which probably doesn't have FP wired into the body) is no longer involved.

And if you're having a fuel starvation issue why not help it along just to make sure. Pinch the return line withh vise grips or something. Could just be a regulator.

Sorry for the rant and have fun!

CLIFF NOTES: In cressida you have to treat the green wire behind glove box the same as you'd treat the green/red wire in any other toyota. Don't ever use the green/red from the CRESSIDA ecu connector no matter how much you think it makes sense! It's +9v gayness!

[jaime.g]

well i just got done plugging the fp resistor back in and the car revs great and idles perfect. looks like my inital wiring for everything turned out ok.


thanks for all the help guys , i really appreciate it

[jaime.g]

Some random thoughts on this.

If you're using anything newer than an x81/a70 ecu the fp and d1 pins won't function properly. You have to go straight to the circuit opening relay.

And fwiw the FP resister doesn't do anything unless you swithch to it. This is a function of the ecu not the chassis. To bypass all nonsense go behind the glovebox, look for the big gray plug. In the corner of said plug is a solid green wire. Ground it!

The 12v side coil in the circ op (and subsequently the fp relay) will be swithched by the key. Basically the body harness now thinks there's a 7m AFM telling it "go full throttle" all the time. Remember they both share +b1 (efi relay output) as a source.

This all works because you have to ground the other side of the coil. The STA coil in the circ op bypasses this because there are actually 2 in there. The start signal is the hot side of the second coil. Stop cranking and fuel goes away.

If you have an x81/a70 ecu make sure you put fp from the ECU to the green wire I've just described. The green/red wire everyone loves so much is the low voltage side of FP relay in the cressida body DON'T USE IT!!!. That's the circuit you cut when you removed the resister which is a good idea anyway. I think the reason this trips people up is because this wiring scheme isn't typical for toyota. The corolla, supra, etc are the exact opposite (ie: the fp wire colors match up).

Dude if you were running the low voltage side (which I'm sure you were) then you just did yourself a favor withh this whole situation. You might not have lasted long withh a fuel pump running at 9v under boost.

Btw, you're essentially doing the diag box trick except the engine harness (which probably doesn't have FP wired into the body) is no longer involved.

And if you're having a fuel starvation issue why not help it along just to make sure. Pinch the return line withh vise grips or something. Could just be a regulator.

Sorry for the rant and have fun!

CLIFF NOTES: In cressida you have to treat the green wire behind glove box the same as you'd treat the green/red wire in any other toyota. Don't ever use the green/red from the CRESSIDA ecu connector no matter how much you think it makes sense! It's +9v gayness!

i did my wiring like this. http://jzxproject.com/bbs/viewtopic.php?t=1981

if this is the 9v way, i'll just ground the green wire like you told me to do so.

[Jason]

now youve got that squared away.

www.rockauto.com and order yourself some brand new coilpacks. thank me later.

[Jacob]

find someone withh a JZ and test your coil packs on theirs first.

[WhoreMouth_Jr]

Hey sorry to dig up old post.
But im having similar problems.
The first couple times i started up the 1j it ran fine sound good reved smooth..
Then one morning it just didnt start(day before let it run for a few minutes to see if temp guage was working). Changed the plugs started up alright but didnt drive wouldnt go above 2k rpm
So im thinking maybe might be wiring but im not sure
heres 1/2 of my 5m wiring stuff


I hooked up that wire the green yellow one going from Circuit opening relay to FC on the 1j ecu. Thats the only wire concerning the fuel pump i wired up to the 1j ecu, should i hook up the FP on the service connector? Should i also bypass the resistor in the engine bay like you mentioned above.
Or could it be because i have open dump(couldnt get downpipe to fit yet) its making my car run rich because the o2 is taking too much fresh air?

thanks

[Mo]

You should check your TPS

[Jamieson]

I actually ran into this same problem on an '08 Camry 6cyl. Coil #2 was shit and it threw a code for misfire on that cyl. but the car would run and drive. I put a new coil in and now the car would start for a sec and die, and it had misfire codes for ALL cylinders. I called the dealer and they tried to give me some bullshit about me having to bring the car in to them so they could relearn idle on the car. Fuckin dealer. So I said fuck it and bought a new new coil, put that in, and now the car starts and runs fine with no check engine light. I guess the first new coil was defective. So in my experience one coil can definitely cause your issue.