First swap start…. Fail

[staticpage]

Just got my 1jz in and tried to start it, I expected to have to work out kinks but this thing is kicking my ass. I’m using a jzx90 ecu In a ma70

Here is what it’s doing:

I crank the car it fires immediately (don’t know if its just a few cyl or all that are fireing). I tried unplugging one coil at a time and cranking it, end up braking two of my new ends (worst design ever). But when I do this it still fires immediately no matter what coil I unplug. If I crank the engine and just make it eat the starter for say 5-7 secs, the car fires immediately and sounds healthy then dies (all this under the first second) then it just cranks and kind of tries to start but not as healthy as when you first crank it.

My diag:

I’m getting spark, I took out the coils and grounded a sparkplug on the intake and all six are firing when I crank it.

Now the fuel is where the problems at. I got desperate to see what the injectors where doing so I unbolted the rail and watched the fuel spray wile cranking the car (not recommended but does work). It seems like every injector is pulsing but after a split sec. the injectors stop spraying. I also observed that some of the injectors maybe two-three are spraying more than the others.

Things I tried that did not work:

I thought maybe a pump problem so I ran the pump off a second battery. I also tried to ground the water temp sensor but I get a cel for missing water temp sensor and the injectors don’t fire at all with a cel on. I wired a led to a few of the injectors to watch the pulsating, the leds start off bright then as crank time progresses they get more and more dim.

At this point I’m suspecting the ecu to be faulty which is ok cus jzx90,jzz30 ecu are cheap.

Could a faulty cam/crank sensor cause this? Any insight to something I might of missed? I’m doing all this by myself so I just need some ideas that I might of missed.


and in general because I don’t want to start a new thread my throttle cable I bought for a mkiv is to short. Wtf?

 

[scottiedawg66]

did you jumper for codes? Sounds like a injector cleaning would be a good idea since dirty injectors can ruin an expensive engine. Also agree the ECU seems like a issue, will it run if you hold it open, or does it die no matter what?

 

[RockPaperSwoRD]

throttle cable: goto the junkyard and look for a v6 camry, it has the perfect length and is alot cheaper. im running one on my 1jz and its perfect, it even bolts up to the firewall with the exact same bolt pattern

 

[staticpage]

@ scottiedawg66 no codes wont even spray fuel if i make it have a code like pull o2 sensor. and i cant hold it open because the $60 cable i bought doesnt work.

@RockPaperSwoRD right but why wont this $60 "swap cable" work

 

[scottiedawg66]

does the CEL flash repeatedly like it should when you jumper? if you have a 2nd set of hands you can hold it open and have someone crank

 

[bigaaron]

Move the bracket back one bolt for the throttle cable.

 

[10secdream]

I would check your crank and cam sensors.

 

[staticpage]

I’m going to check the camshaft/crankshaft sensors today and see if there alright. could not find the test ohms easy so here it is for a 2jz should be the same.
Check resistance of camshaft sensor
cold: 835-1400 ohms
hot: 1006-1645 ohms
crankshaft sensor
cold: 1630-2740 ohms
hot: 2065-3225 ohms
and I’m going to pull the fuel rail and bench clean the injectors with my old Honda injector cleaner setup. Pump acetone through the injectors then Ultrasonic clean them for a wile. And change the fuel filter.

And as far as the cable goes it’s just not long enough to reach the throttle when I connect it, It holds open the throttle half way. I can check to see if everything is lined up at the pedal but there’s not much to it. if you look at my pic I posted that’s stretched all the way out. It still needs a few more inchs to reach around to the spot it connects to I tried to make it fit but then it just holds open the throttle.

 

[staticpage]

Finley got around to working on this project again. Still have the same issue tried a new known good ecu. Cleaned injectors there working fine.
I see in the wiring diag. that there is a fuel computer for the jzz30 do we wire the ecu a special way to bypass the fuel computer? I have two harnesses one has (I think) the cam POS having shielded wires. The other harness I’m using seems to not be shielded, might this cause my problem?

 

[aphxero]

For x90 ecu just ground the cold side of the circ op relay in the body harness. This would be the wire from the maf on the body harness. This is effectively like doing the 12v mod. Pump turns on with +b1 from efi relay. The ecu doesn't care if the fuel ecu is there or not it just assumes it is.

Why not rule out engine position sensors by running it on carb cleaner? If the position sensors aren't working or a crank tooth is messed up it'll be pretty obvious. It should rev up smooth on carb cleaner.

How about unplug the map sensor? It'll idle just really rich. worried about CTS? Disconnect and put like a 2 or 3 ohm resistor in the plug. That should put it rich as hell like 0 deg C.

I've done lots and lots of jzx90/zz30 swaps and I've never seen one ecu bad. That's usually only in broke dick a70/x81 computer.

It's retarded how hard it is to get them to throw a code too. You can have no o2,trac, auto trans anything, 2nd tps, iscv, any of the vsv and it really doesn't care and runs fine.

Good luck

 

[staticpage]

thats good info thanks.
but if i even unplug any sensor map,cts, cam, o2 it won't even sputter and try to start it just cranks and the CEL come on for the sensor I unplugged. I mean if i even unplug the map and turn the key to on the cel sees it missing. and the cap in my jzx90 ecu where shot i replaced them. then tryed a jzz30 ecu got the same from both.

right now i have the fuel pump wired in to the battery with only a fuse so as soon as the battery is conneted it pumps.
i cleaned the injetors today and flow tested them they where fine off by 3% max.

it's just really strange every thing pointed to a bad ecu and then i get a known good ecu and it does the exact same thing. so i must have a bad sensor that tests good according to TSRM or i have a wiring issue.

 

[staticpage]

tested sensors with in 2jz tsrm spec
cam1 1107 ohms
cam2 1104 ohms
crank 1085 ohms <fail

so is the 2jz crank sensor the same as 1jz?

 

[aphxero]

Yeah same sensor.

 

[10secdream]

tested sensors with in 2jz tsrm spec
cam1 1107 ohms
cam2 1104 ohms
crank 1085 ohms <fail

so is the 2jz crank sensor the same as 1jz?

I just tested all my cam and crank sensors yesterday and I had similar results. I have confirmed that all my sensors are working. I think the TSRM for the crank sensor is incorrect as my crank sensor does indeed work.

 

[staticpage]

Ok I have updates I took the day off to mess with the car because its getting warm and I want to drive it.

I have not changed anything from the first post other than testing almost every sensor, doing a leak down, and compression test (cold so just about useless). Everything checked out.

I tried starting fluid, well fuel in a bottle sucked thou a vac line. And I can get it to start (after fighting with a bum starter), after a few secs of cranking it will run on its own without me feeding it fuel.

The idle surges BAD, almost from 1200rpm down to 500rpm if given any throttle it spits and sputters misfiring its way up in revs. I unplugged each injector one at a time, everyone is firing. When I unplug one the car runs a little worse. It is using to much fuel I can feel the injectors pulsating like crazy, there&#8217;s fuel coming out of the downpipe.

The CEL puts out code 31 now after I shut it off. I think that&#8217;s a map sensor code. So im going to replace the map and test this one and update after i try a new map.

thanks to aphxero for the starter fluid idea I was getting tired of loosing