1uz starts and dies :/

The 1UZFE EGR Delete Kit is available for sale here.

jkb_and

New Member
Messages
10
Location
Poland
Hi I`ve got problem with my 1uz-fe after swap.
I put it into nissan 200sx. Now for some reason after start id dies.
Troublecode says : airflowmeter, air temperature, throtle position sensor.
I replayced them and code says the same. I have no idea why.
the engine stops by itself after 2sec 15 or half a minute - no rule can be made.
Can anybody help me out?
 

lill daddy

New Member
Messages
112
Location
Christchurch (NZ)
have you got the pipe from the idle stepper motor (in front of the intake manifold) piped in after the air flow meter? i thought i could just use a little air filter on it but it has to draw air past the afm at idle...
 

jkb_and

New Member
Messages
10
Location
Poland
I think AFM is correct because I boght whole Lexus LS400 just to get complete engine. I swaped entire engine with all the aternator stuff, pipes and so on.
Only airfilter box didn`t fit in and got rid of a/c compressor.
The small pipe after AFM is attachet to nothing and can intake air freely.
I`ve posted video on yt showing how it looks like.
http://www.youtube.com/watch?v=PHx8t26PVdo
 

samsdad

Member
Messages
561
Location
Perth WA
You have no power to the injectors. She's starting off the cold start injector. Test your wiring at the injectors as with ign on you should have 12v on one side and the ecu does injector pulse on earth return
 

Zuffen

Super Moderator
Staff member
Messages
5,525
Location
Sydney, Australia
I've also had it where the power to the fuel pump drops out when the key is released.

A simple wiring error and it took me hours to figure it out.
 

jkb_and

New Member
Messages
10
Location
Poland
First of all yesterday I took my car to better electrician. I simply got sick and tired of the previus garage.
Troble code says there is a fuel pump problem so it`s close to what y`all say.
My question is - does every 1uz have cold start injector??
We looked at my (1996year and sold in UK) and couldn`t find it.
What albout immobiliser? I`ve heard it effects ONLY starter but maybe that is not true.

I realize my questions might be stupid but back in 1996 there were probably 3 Lexuses LS400 sold in entire Poland so there is no mechanicks realy familiar with it down here.
 

jkb_and

New Member
Messages
10
Location
Poland
I`ve got stuck. We checked out all the sensors and they are good.
Beeing desperate bought another ECU and replaced it. The weird thing is for several minutes the engine was running just fine.
Then we tried several times starting and shuting it down and....we got the same effect as at the very beggining :confused:
 

jkb_and

New Member
Messages
10
Location
Poland
I haven`t check coils yet. But it looks like the current on injectors is beeing shut down - the spark is still on when the engine stops.
There is something that cuts off the power on injectors for unknown reason.
I have an osciloscope but no scantool.
 

a7mgte

New Member
Messages
22
Location
Morro Bay, CA
I just watched the video....holy smokes, is the engine even bolted down? It should not move that much when being started. Looks like it'd rotate all the way over if it actually had a load on it. Mine doesn't even wiggle, I don't use the lexus mounts though specifically to avoid the engine rocking like that.

Back to the problem at hand though, the little nipple behind the AFM that you mention is open...cap it. That's the one for the power steering idle up, and many people delete it anyway. The ECU can't properly cope when it doesn't know how much air is going through the engine, and you'd be surprised at the massive difference a vacuum leak that that can make.

After the engine dies, is the fuel pump still running? You mentioned a wiring issue to the fuel pump, how is it wired now?

If you're just using a fuel pump relay instead of the fuel pump computer, there are two pins to the fuel pump computer, one tells the pump to turn on, (FC I think, maybe FP?) and the other tells it how fast to run(FPR). I don't have the schematic in front of me right now though. If you have it hooked to the wrong one, the fuel pump will only work while the ECU is telling to it to run at high speed. (During startup and under heavy load.) So as soon as the ECU thinks it's slowing down the fuel pump, it's actually turning it off.

Mine just runs through my circuit open relay, but my 1UZ is in a toyota. Because the Lexus fuel pump computers seems very prone to failure, and it presented itself as one more headache I didn't want to deal with. So if you are using the Lexus fuel computer, maybe look to make sure it's working. God knows they fail almost as much as chevy trucks.
 

jkb_and

New Member
Messages
10
Location
Poland
You`re right - when the video was taken the engine was not bolted down.
Now I`ve got poliuretan motormount.
I tried to wire the fuel pump directly to the battery but effect was the same.
It looks like fuel pump works about 2sec after engine stops. It seems power on injectors disapears at some point.
By the way I also replaced Lexus fuel pump for Nissan pump and nothing changed.

I have heard only UK version of Lexus LS400 (1996) have instaled by factory immobiliser - is that true info?
Anyone got wirering diagram of 1uz-fe including immo??
 
Last edited:

George_R

Well-Known Member
Staff member
Messages
1,068
Location
Russia, Moscow
Which error codes are still there?

Since you once had it running for more than 3 seconds it's not immobiliser being the reason.
Try running it with AFM disconnected. Check if AFM part ### corresponds to that of the ECU. See if AFM receives power supply and ground. Make sure your igniters are firmly grounded.
 

shoob

New Member
Messages
32
Location
ATL GA USA
same issues, but in a 93 ls400....all factory. ive replaced the afm, cts, plugs, tested with new coil pack, still nothing. i will also note that the injectors are very loud when it does this.
 

Jan Venter

New Member
Messages
51
Location
Hankey, Eastern Cape, South Africa
Iam batttling my of trying to start my uzfe. my fuelpump is running at close to 4 bar have a guage connected. Seeems there is no neutral on injector, so no fuel into culinders i still cany get fault codes going so have to rely on ouwn diagnostics. I started of with a 95 engine andafter it knocked a hole in the block i gat a 92 model engine. i swapped the intake and wire loom and ECU complete with all sensors eetc so i have in effect a 95 engine. It will start if quickstart is sprayed into the intake. Somehow the ECU does not signal the injectors to deliver fuel, did i connect something or not connect? Please help Jan Venter
 
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