Fuel in exhaust / Injector stuck? (2 Viewers)

[Vlex]

Hi guys!

I've changed my spark plugs, spark plug seals, cap, wires and valve cover gasket yesterday. Engine (1FZ-FE) ran better than ever. But today I got a p0301 code (misfire cilinder 1).
Upon further inspection I found fuel leaking from the exhaust gasket at the catalytic converter and fuel in the tailpipe as well.

For now I can think of 2 cases:

- stuck fuel injector (probably at cilinder 1). Could be because I disturbed the harness near the firewall/egr pipe. I wrapped the harness a while ago to prevent damage from the EGR pipe. New wrap still looks good.

- I havent reset the ECU yet after changing my spark plugs. Could it be the ECU needs to relearn and that it is giving to much fuel? The old spark plugs were in a bad shape.

I hope it could be option number 2, but probably not?

In case of a stuck injector: is there a way to check if there is a short on the harness without taking it all apart?

Thanks for you input!

 

[robnicko]

Sounds very much like zero spark in that cyl, is the spark plug soaked in fuel as well?
could be the lead going to the plug is faulty, spark plug itself faulty or Dist Cap faulty in that no spark is going to that plug so the cyl is just pooling with fuel and eventually into the exhaust.

 

[Vlex]

Sounds very much like zero spark in that cyl, is the spark plug soaked in fuel as well?
could be the lead going to the plug is faulty, spark plug itself faulty or Dist Cap faulty in that no spark is going to that plug so the cyl is just pooling with fuel and eventually into the exhaust.

I checked the #1 wire with a timing light and it is sparking. Haven't checked the plug yet. But the truck also runs on LPG and then it runs fine. So I don't suspect the spark plugs. But I will be checking all the wire with the light just in case.

 

[secretasiansam]

Another potential wire short happens behind/under the glove box. The main harness into the ecu rubs. It happened to me and stuck injector 6 on. Tons of fuel in the exhaust.

 

[Vlex]

Another potential wire short happens behind/under the glove box. The main harness into the ecu rubs. It happened to me and stuck injector 6 on. Tons of fuel in the exhaust.

Thanks! Will check that as well. And I’ll dive into the EWD to check if I can check for a short at the EGR area with a multimeter from the ECU side.

 

[Malleus]

If you want to check the injector, use a very long screwdriver, or similar long metal object, placed against the manifold where the injector sits. Place the other end against your ear - not in it, of course. You'll hear the injector clicking if it's working.

You can check the injector electrical load by using a mulitmeter on the ECM connectors under the glovebox. The pinouts are in the Diagnostics - Engine section of the FSM.

 

[Malleus]

 

[Malleus]

 

[Vlex]

If you want to check the injector, use a very long screwdriver, or similar long metal object, placed against the manifold where the injector sits. Place the other end against your ear - not in it, of course. You'll hear the injector clicking if it's working.

You can check the injector electrical load by using a mulitmeter on the ECM connectors under the glovebox. The pinouts are in the EG section of the FSM.

Brilliant! Thanks. I’m away from the cruiser for a couple of days. I’ll be diving in as soon as I’m back.

 

[Vlex]

Finally had time to dive in to the problem. Unfortunately haven't been able to fix the problem for now. Things I've checked/done:

- First removed the plug at the ECU behind the glovebox. All the wires are intact in that area. Measured the injector-signal wires for a ground short. Found that the injector wire for #1 (White/Blue) has a constant ground. So this is definitely the problem.
- Thinking I would find a short at the EGR area, I started removing throttle body to take a better look at the wiring harness. Removed all the insulation of the wiring harness near the EGR. Although the outer loom tape was somewhat damaged, all the individual wires are still intact.
- Unplugged the injector plug for #1 at the injector side as well. So now the injector wire is disconnected at both ends. But it still has a connection to ground. Check #3 for reference and this wire has no ground signal.

I'll be checking the rest of the wiring-harness. The short must be somewhere in there....

If someone has another idea. please let me know

Will report back later. Cheers!

 

[inkpot]

Finally had time to dive in to the problem. Unfortunately haven't been able to fix the problem for now. Things I've checked/done:

- First removed the plug at the ECU behind the glovebox. All the wires are intact in that area. Measured the injector-signal wires for a ground short. Found that the injector wire for #1 (White/Blue) has a constant ground. So this is definitely the problem.
- Thinking I would find a short at the EGR area, I started removing throttle body to take a better look at the wiring harness. Removed all the insulation of the wiring harness near the EGR. Although the outer loom tape was somewhat damaged, all the individual wires are still intact.
- Unplugged the injector plug for #1 at the injector side as well. So now the injector wire is disconnected at both ends. But it still has a connection to ground. Check #3 for reference and this wire has no ground signal.

I'll be checking the rest of the wiring-harness. The short must be somewhere in there....

If someone has another idea. please let me know

Will report back later. Cheers!

The injector signal triggers by grounding at the ECU, not by the positive wire , so ground signal is intermittent.

 

[steveLX450]

Finally had time to dive in to the problem. Unfortunately haven't been able to fix the problem for now. Things I've checked/done:

- First removed the plug at the ECU behind the glovebox. All the wires are intact in that area. Measured the injector-signal wires for a ground short. Found that the injector wire for #1 (White/Blue) has a constant ground. So this is definitely the problem.
- Thinking I would find a short at the EGR area, I started removing throttle body to take a better look at the wiring harness. Removed all the insulation of the wiring harness near the EGR. Although the outer loom tape was somewhat damaged, all the individual wires are still intact.
- Unplugged the injector plug for #1 at the injector side as well. So now the injector wire is disconnected at both ends. But it still has a connection to ground. Check #3 for reference and this wire has no ground signal.

I'll be checking the rest of the wiring-harness. The short must be somewhere in there....

If someone has another idea. please let me know

Will report back later.

Finally had time to dive in to the problem. Unfortunately haven't been able to fix the problem for now. Things I've checked/done:

- First removed the plug at the ECU behind the glovebox. All the wires are intact in that area. Measured the injector-signal wires for a ground short. Found that the injector wire for #1 (White/Blue) has a constant ground. So this is definitely the problem.
- Thinking I would find a short at the EGR area, I started removing throttle body to take a better look at the wiring harness. Removed all the insulation of the wiring harness near the EGR. Although the outer loom tape was somewhat damaged, all the individual wires are still intact.
- Unplugged the injector plug for #1 at the injector side as well. So now the injector wire is disconnected at both ends. But it still has a connection to ground. Check #3 for reference and this wire has no ground signal.

I'll be checking the rest of the wiring-harness. The short must be somewhere in there....

If someone has another idea. please let me know

Will report back later. Cheers!

My 97 shorted on the glove compartment lower reinforcement bracket , the edge of the bracket is sharp enough that over time it wears through the insulation. I found it quick by moving the harness around with the engine idling.

 

[secretasiansam]

This is where mine shorted.

My 97 shorted on the glove compartment lower reinforcement bracket , the edge of the bracket is sharp enough that over time it wears through the insulation. I found it quick by moving the harness around with the engine idling.

 

[Vlex]

Found the problem!

I managed to trap a wire from the LPG system between the valve cover and block. It’s the wire which piggy backs from the injector wire #1 and goes to the LPG ECU.
Trapping it underneath the valve cover made a pretty solid ground point…

Fixed the wire and cleaned up the complete wiring loom. And insulated the factory harness by the EGR.

Almost done putting everything back together but ran out of daylight. Will be testing tomorrow but I expect this fixes the problem

 

[Vlex]

It appears that fixed the problem! Just started it up and after smoking out the neighbourhood from the petrol which was still in the cilinder/cat/exhaust, I took it for a test drive. All looks good and it runs smooth.

Thanks for all the input!