No fuel no spark, engine cranks

[Drain]

I have a 95 sc400 that I have rebuilt; broken valve engine will crank and I am sure my grounds are all good. The spark plugs have no spark on either bank and I do not hear the fuel pump engage at all. Starter will crank the engine but it will not fire. The only wiring I have done to the vehicle is wiring in electrical fans to the ign switch. Where should I start to fix this problem? I have no CEL so I wonder if it is the ecu.

 

[P Bateman]

If the CEL isn't lighting up, then the ECU isn't switching on... or is malfunctioning.

Start with the basics in order - battery - fuse - ECU - earth
Ensure you have +B constant (BATT terminal)
Ensure you have +12V with the ignition switch turned on (IGSW terminal, +B and +B1)
Check all the ECU grounds have good connection to ground

 

[Drain]

If the CEL isn't lighting up, then the ECU isn't switching on... or is malfunctioning.

Start with the basics in order - battery - fuse - ECU - earth
Ensure you have +B constant (BATT terminal)
Ensure you have +12V with the ignition switch turned on (IGSW terminal, +B and +B1)
Check all the ECU grounds have good connection to ground

Thanks for the advice Bateman. I found out the ecu wasn’t completely plugged in with the harness (don’t let your friends plug in your ecu)
CEL came on and I was able to diagnose cam sensors and crank sensor. Got it on order right now

 

[Drain]

Thanks for the advice Bateman. I found out the ecu wasn’t completely plugged in with the harness (don’t let your friends plug in your ecu)
CEL came on and I was able to diagnose cam sensors and crank sensor. Got it on order right now

Starting this thread back up

Replaced camshaft sensor, crank sensor, and crank sensor plug which looked fouled and I still have code 13, I cleaned 1 cam sensor and the code 12 I had went away so I know the left cam is good.
Any ideas on where I should go next?

 

[P Bateman]

DTC 13 is caused by the crank sensor cutting out while the engine is running, or logical errors in the pulse count the ECU is receiving from crank and cam sensors. If you have replaced the sensors, it likely to be a poor connection (open or short circuit) in the wiring between sensors and ECU, or your timing belt was not installed correctly during the repairs you've done.

Double check the timing belt is installed correctly
Use a multimeter to check resistance from each terminal of your sensors back to the ECU. All resistance reading should be less than 1 ohm.
Anything more indicates a poor connection or open circuit

Possibly not the diagram for your vehicle but this is what you'll need to test.

 

[Drain]

Starting this thread back up

Replaced camshaft sensor, crank sensor, and crank sensor plug which looked fouled and I still have code 13, I cleaned 1 cam sensor and the code 12 I had went away so I know the left cam is good.
Any ideas on where I should go next?

Update:

Removed random electrical tape on right cam connector, found multiple wires which are corroded green that lead to this unknown connector.
The brown and green wire come from the cam connector

DTC 13 is caused by the crank sensor cutting out while the engine is running, or logical errors in the pulse count the ECU is receiving from crank and cam sensors. If you have replaced the sensors, it likely to be a poor connection (open or short circuit) in the wiring between sensors and ECU, or your timing belt was not installed correctly during the repairs you've done.

Double check the timing belt is installed correctly
Use a multimeter to check resistance from each terminal of your sensors back to the ECU. All resistance reading should be less than 1 ohm.
Anything more indicates a poor connection or open circuit

Possibly not the diagram for your vehicle but this is what you'll need to test.

View attachment 25907

I will do that test when I get home, thanks for the input.

The 6 pin connector that the cam sensors end up into is cracked and 3 plugs in the connector are loose and corroded. I’m going to try and replace that after i check the resistance

 

[Drain]

DTC 13 is caused by the crank sensor cutting out while the engine is running, or logical errors in the pulse count the ECU is receiving from crank and cam sensors. If you have replaced the sensors, it likely to be a poor connection (open or short circuit) in the wiring between sensors and ECU, or your timing belt was not installed correctly during the repairs you've done.

Double check the timing belt is installed correctly
Use a multimeter to check resistance from each terminal of your sensors back to the ECU. All resistance reading should be less than 1 ohm.
Anything more indicates a poor connection or open circuit

Possibly not the diagram for your vehicle but this is what you'll need to test.

I have repaired the broken connector and the CEL has changed. It blinks consistently on and off quickly. Everything I’m finding online it just says it’s something that needs fixed with no clues.

Worth to add timing belt is in correct markings when engine is TDC/ 0 degrees on timing cover

 

[P Bateman]

Fix one problem, only to find another.

Normally a fast flashing CEL means the ECU is in test mode... do you still have the jumper pins connected to the diagnostic connector?

Does the engine start now?

Someone else may be able to chime in here, but I've never checked cam timing from the TDC mark on the timing cover - I've always removed the crankshaft pulley and checked the actual timing belt marks.

 

[Drain]

Heading home with a new battery now I didn’t have voltage to start the car. I checked timing via the marks on the cam pulleys. I repainted where correct timing is so I don’t have to removing too much. I will update on if it starts soon!!

 

[Drain]

Fix one problem, only to find another.

you’re gosh darn right.

Got the batt charged up enough to supposedly start the car.
I hear the fuel pump kick on and crank the engine but it seems to have no spark. My battery is definitely shot so I have a new one coming Thursday. If it’s not the battery, what would you suggest?

Thanks for your help!

 

[P Bateman]

Did the check engine light go out?
Or, is it flashing and, if so, what code(s) is it giving you?
How are you confirming it has no spark?

 

[Drain]

Did the check engine light go out?
Or, is it flashing and, if so, what code(s) is it giving you?
How are you confirming it has no spark?

The check engine light just flashes with diagnostic jumped, with jumper wire removed it is solid. I am not able to read any codes

I have an in-line spark plug tester

 

[P Bateman]

All good - CEL should be solid with the ignition switched on and engine not running
Can you confirm you are following the diagnostic test processes as follows...


Diagnosis Inspection (Test Mode)

1. Battery must be +11V or more, throttle valve closed, trans in neutral, AC switched off
2. Turn ignition switch off
3. Insert jumper between terminals TE2 and E1
4. Turn ignition switch on (CEL should be flashing fast, every 0.13 seconds)
5. Try to start engine
6. Turn the ignition off
7. Remove the jumper
8. Now follow the next procedure to see if any codes have been logged

Diagnosis Inspection (Normal Mode)

1. Turn ignition switch on (do not start engine)
2. Insert jumper between terminals TE1 and E1
3. Read diagnostic codes

 

[Drain]

lots of codes!!!

I am seeing 13, 14, 15, and 16.

I read a forum on clublexus that stated if the igniters produce weak signal it could cause DTC 14, 15. Still waiting on the new battery. This is wild I appreciate your help

 

[P Bateman]

Just make sure the igniter housings are earthed properly first!
It doesn't show in the wiring diagram, but the internal igniter circuit finds earth through the aluminium case.