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

[profile18]

Alright for sure, i will definitely pop the ECU box open tonight and check that out.

 

[poorsupra]

we can throw in my 1uz ecu and check.

 

[profile18]

How is a good way to look for a bad ECU i popped it open tonight and took a look but everything looked fine.

I didn't see any burn marks from leaky capacitors or anything like that, could some capacitors be leaking or faulty but not be showing dramatically?


Bryce i'm pretty sure your ECU is a three plug like this- (93' Sc400)

And mine in a four plug like this- (93' Ls400)

Which sucks because i would really be down to try.

 

[profile18]

So i went ahead and got another 93' LS ECU and plugged it in and its still doing the same thing.

Also it is still throwing a code 48, i went ahead and unplugged the crank position sensor to see if it would throw a code for it and nothing still 48.

So i'm thinking maybe my check engine light is not working properly but it is wired par the wiring guide 100% so i dont know.

checked spark yet again = good.
checked fuel yet again = good.

I have also researched my symptoms and have come up with the idea that it is maybe my crank position sensor or maybe my cam position sensor or worst case a broken camshaft.

Next junkyard trip i'm going to grab some sensors and swap them out and see if anything changes.

 

[sideshow]

u now need to dig deeper
check every injector for pulse with noid light
make sure every injector is free and clicks

check that spark plug leads are ok and put a timing light on all leads and check for spark

even spray fuel down throttle to see if it fires

 

[profile18]

So i've checked my fuel injectors they are all good with good pulse.

I checked all my plug wires i have iffy spark on cylinder 5 and no spark on cylinder 4 which are on opposite sides of each other.
they are original wires so i should just change them anyway, but i would think it would still start minus two cylinders.

Put a different crank position sensor in for shits and giggles.

i played around when trying to start it i held the throttle all the way open when cranking it and it wants to shoot flames out of the throttle body & sometimes backfires.

So i'm thinking i'm getting spark and fuel but my valves are not opening at the right times? timing issue? do camshaft sensors like to go out?

I'm not sure on what else to check.

 

[lill daddy]

just fyi... my ecu had no visible signs of leaking caps etc it just plain shit itself... and like i said it was firing random sparks to random plugs in no order and effectively putting the timing out...

 

[gloverman]

have you done a compression test?

 

[poorsupra]

we tried to compression check it, his tool isnt the best. i need to bring my compression and leakdown tester over and see wassup.

andy- did you check the resistance of the plug wire? is it intact? or is it the plug itself not firing? we need to trace down the problem to the specific cylinders. something did CHANGE from the time we bled your clutch, started up. ran fine. idled well. revved okay. then when the oil cooler was introduced into the mix is when things went cattywompus! haha. excess oil caused a failure of some sort....what it did? im pretty stumped. but the leakdown should shed some light on things.

i swear if i turbo the SC before your cressy is running ill be dissapointed! p.s. got a carbon fiber trunk to match my hood. ;-]

 

[profile18]

I have recently picked up another 93 -94 ECU from the junkyard and plugged it in and it still is doing the same, unless the one from the junkyard is bad also.
That does kinda sound like what its doing though, but what are the chances that two ECU's are bad.

Yeah like poorsupra said i tried to compression test it but my tool is old and on its last life.

When i checked for spark i just pulled the plug out and plugged it into the wire and watched if it sparked while i tried to turn it over.

Ive had the oil cooler since the beginning from when i first started it till now, thats why i'm so stumped because it ran fine until i put that last bit of extra oil in.

Haha i know man i better be driving this thing everyday before you turbo your SC.

Wait what!? when did you get a CF hood!? no to mention a trunk.

 

[poorsupra]

i come walking up in the driveway with my leakdown tester and now we dont need to use it. upon closer examination of the timing belt there was a mystery grove in it, along with lots of fibers frayed, with rounded teeth. the water pump pulley sheared off the pump itself. concluding that the belt must have jumped timing when it broke. so andys gonna order up a t-belt and water pump, retime the motor and it should be golden.

 

[sideshow]

so I was on the right track hehehe

 

[profile18]

Damn water pump pulley, it was also running into my idler pulley bracket which put metal shavings everywhere. I had a sparkly, grooved, frayed timing belt.

 

[profile18]

So i am in the process of re-timing, replacing timing belt/ water pump etc...
and i'm curious about this pipe, it used to got to the air filter box.

My question is can i remove it? plug it? or just leave it open & wht does it go to.

I have only been able to find them on 93' ls 400's but no info about it, any ideas?

 

[profile18]

Anybody have an idea of what that pipe is in the post above?

On a different note i marked all the timing marks to see what wasn't right,
Crank is at 0, the left Cam is dead on, the right Cam not so much as you can see in the picture.



this is what occurred from my water pump pulley sheering off and what i'm guessing jumped teeth.

So i'm glad to say i think i found the problem.

 

[poorsupra]

well since andy(profile18) is neglecting his thread ill chime in with a new timing belt, wp, and correct timing and he finally drove his 1uzfe w58 cressida. i welded in his o2 bungs on his modified header and now i gotta fab him up an exhaust.