1uzfe Was running, now just cranks & doesn't fire.

[profile18]

I have recently put a 93' UZ into my 89' Cressida, everything seemed fine it was running good idled fine just had low oil pressure do to a oil cooler and relocation kit.

I put 5 quarts on top of the standard 5 quarts needed making 10 quarts in the motor, so i started it and let it idle to see if the oil pressure light would turn off and to check/ top off coolant levels etc...

It idled great for about 30-45 sec then just died, now it just cranks over and wont fire and sometimes spits smoke out of the intake.

note that i've started it before 3-4 times with no problems.

*fuel pump/ pressure is good.

coulld it be spark plug/wires?
sensors? (crank, cam)
Ecu?

Help!

 

[profile18]

I checked my codes today and the only code that comes up is code 48,
does anyone know what code this is for? I checked the diagnostic code sticky and there is only 47 not 48. i checked multiple times and it was definitely 48.

This is the only code its throwing over and over.

 

[profile18]

After searching around i found this.

48 - Sub-throttle position sensor signal is 4.3V or higher, or sub-throttle position sensor signal is 0.2V or lower when idle switch is OFF

but its for (TRAC OBDI Diagnostic Codes)

I'm pretty sure i don't even have traction control.

Any ideas?

My UZ is out of a 93' LS

 

[gloverman]

Complete a standard diagnoses on it. Check for power where there should be power , check earths , check spark , check fuel etc etc.

 

[profile18]

Grounds - Good.
Spark- Good.
Fuel - Good.
Fuses- Good.


It wants to crank but does not fire,
I checked my lines for my oil cooler/ relocation and i had them mixed up so i'm pretty sure that a good amount of those 10 quarts of oil were stuck in the motor, does anyone have any experience with accidently over filling these UZ's. any stuck valves i should replace PCV valve etc...?

Keep in mind that it wasn't running very long maybe 30 seconds at the most, i checked the oil still very clean no signs of foaming/ dark burned oil.

I have drained 5 1/2 quarts out of the engine and put the stock oil filter back on in its original location to diagnose and hopefully fix the problem.

Any ideas?

 

[Zuffen]

Overfilling it won't do any real harm.

It may smoke a little but it'll settle down.

They can and do foul plugs easily and don't like starting until they are replaced or well cleaned.

I'd try a new set of plugs.

They don't have to be platinum.

Any plug that fits will be OK to start it up.

If it starts give the old plugs a real good clean or replace.

 

[profile18]

That is really good to hear i'm really freaking out on this, so you think a good cleaning or new set of plugs should do the trick? no clogged valves i should have to worry about?

Ill definitely try and clean my spark plugs up or go ahead and buy some fresh ones and keep my fingers crossed it would really be a bummer for all this work to be for nothing, not to mention extremely frustrating.

Thanks for the feed back.

 

[poorsupra]

i tried to help diagnose this 2 nights ago, I can second that the grounds/fuel/spark are correct. there are forward fires and pops out of the intake and ALL vacuum outlets in the manifold.

they seem like they want to breath and fire up, but small deposites of oil spray out the orifices when cranking, accompanied by white smoky puffs.


hopefully there is just oil in places it shouldn't be, and when it seeps out she will fire.

 

[lill daddy]

when my conversion did the same thing it turned out to be the std ecu after chasing and checking a million things changed the ecu and started off half a crank.... id try borrow or get your hands on another ecu....

 

[profile18]

Alright lill daddy i'll definitely keep that in mind, thanks you.

So far i've just been double checking connections, power etc...
i have also drained all the oil to let it sit and put the oil filter back to stock position and removed the cooler.

My plan is to let it sit for a couple days then clean the spark plugs, Then put the appropriate amount of oil in and see if it will start with the cleaned plugs and stock oil capacity.

If that doesn't work i'll look into getting a different ecu and or new plugs/wires.

 

[sideshow]

worse case scenario
snapped camshaft due to no oil pressure

 

[profile18]

***** I really hope not.

It still seems to crank fine.

 

[poorsupra]

well ROO dont trip if it is a camshaft, theyre so easy to get. the oil light WAS on.

sideshow- can you explain the details of how a cam can snap due to lack of oil pressure?

 

[sideshow]

it's prob not a broken cam as they are rare
but oil pipes in head block up and get no oil
and cam journals get marked
I've seen one broken cam and afew seized cams
and I've see a cam timing gear snapped at end of cam

 

[profile18]

Well i sure hope not, i'm pretty sure they were getting plenty of oil. I had traces of oil coming out of my spark plug tube seals.

I'm going to mess with it tonight, clean the spark plugs, fill it with the appropriate amount of oil that is called for with stock filter location and see if it will start.

 

[profile18]

Cleaned all 8 spark plugs, put oil in, tried starting it and still nothing.

It cranking fine but not firing, it is still having that back pressure problem where there is spurts of air coming out of the IACV and intake manifold in general.

 

[Yotarip]

Make sure your ignitor/bracket is securely grounded. will not run if this is not grounded to the chassis or engine.

Also check your crank position sensor (behind the crank pulley)on the driverside. Grab one from your local junkyard and test it out. Also check the wires as they go into the connector for the sensor. I've seen a few badly frayed enough to open the circuit. It's a long shot because it should have shown up in you diagnostic test.

One more thing. I'm almost finished with my 1uz swap into a 87 toy truck. I grabbed an old battery to start it and it had enough juice to turn the motor over and it ran fine the first few times. Further attempts to start it failed. It would turn over ok but it would not run. I messed around with it for a few days and finally noticed that my check engine light would go off during cranking. This let me know that the battery was weak. Cranking the starter was consuming all the power and deactivated my EFI relay. I fully recharged my battery and she started right up on the first try.
So long story short, make sure your battery is fully charged.

 

[poorsupra]

.
So long story short, make sure your battery is fully charged.

definitely! these uz's need the power!

 

[profile18]

Ignitors are definitely Grounded good.

My cluster lights/ dash lights do dim rather alarmingly when i try and start it.
I have been rather skeptical about my battery but i have charged it everytime i go to work on the car, So hmmmm.

My crank position sensor looks slightly newer and the wires look fine.

I'm also just confused on why i'm getting back pressure out of the intake.

 

[lill daddy]

When my ecu was stuffed it would fire at completly random times causing back fires through the inlet and exhaust... still betting its the ecu.... you can open them and look for leaking capacitors and burn marks on the wiring etc