Close to giving up...can't find the misfire! (1 Viewer)

[SpeedAgent]

Guys,
I've been at this for months. I have replaced so many things and done so many procedures I've read through on Mud i can't count them all. After my used engine was installed in my 94' I started having issues with a shudder/misfire/erratic idle/occasional stalling and so far I've replaced; plugs, wires, rotor, cap, fpr, fuel pump, fuel filter, adjusted the TPS, checked and wrapped the wire loom next to EGR pipe, disable EGR (pretty sure the valve is closed), checked and cleaned the air filter, and numerous other things. But, it has become difficult to start (gets worse each day), stumbles from a stop to get going, slightly surges once it gets going, sometimes going up an incline it won't downshift and struggles to accelerate, and it idles horribly sometimes, and sometimes it's so so. When the idle is bad it fluctuates from 200- up to 400/500 and sounds like it's going to stall. When I say "fluctuate" I mean surge up and down through that rpm range instead of being a steady 400 or 600. I've rechecked all of my plugs again just now and they all look the exact same. I have done a visual on the injectors to see if anything was lose or corroded and on the outside it looks ok.

For what I do know;
1. when I changed the fuel filter 2 days ago the fuel that came out was slightly rust colored. I know this is an issue, but nothing changed when I changed the filter, nada. This can't be the entire issue because this thing has run just fine for a little while after the engine was installed.
2. I currently have a code 84 and 85 flashing, which I am under the assumption is related to a possible failing tranny actuator. Not sure if anything is related or not.
3. I disabled my EGR using the wire jumper method. HOWEVER, I do not know if the valve is stuck open or it is closed. I did get an EGR code a few days ago after it was already disabled, but I think that may have been due to a the jumper wire being lose. I did apply a vacuum to one of the EGR lines to see if the rig would stall, and nothing happened. If it is disabled and the valve is closed this is normal, correct?

I don't know what else to do or where to look. The injectors are all clicking, I can hear them when I use the screwdriver method. I don't know what else to do. I have the later model ECU, so that is not the 93' that was an issue. Anything else I'm missing here??????????

Thanks!





-rotor

 

[2fpower]

Looked at your list.. only thing that I hear is an issue that you have not replaced is the Fuel pressure regulator. Have you checked fuel pressure?

 

[Kernal]

Do Code 84 and 85 indicate the ECM issue? What is the part number of
your ECM?

 

[SpeedAgent]

Looked at your list.. only thing that I hear is an issue that you have not replaced is the Fuel pressure regulator. Have you checked fuel pressure?

Yes, the fpr was done last week

 

[SpeedAgent]

Do Code 84 and 85 indicate the ECM issue? What is the part number of
your ECM?

I don't have the part number on me but doing my research it's the correct number for the ECM you want for a 1994

 

[Proven]

Most of my experience working on engines isn't on Toyota. So forgive me if I am wrong.

You've done most of the fuel system and ignition system. The problem persists.

Since you've got a used engine in there, could be a wire pinched anywhere in the harness. It could be shorting. I had this happen with another type of engine (v8 outboard motor) where we pinched a harness and it was arcing against the engine block. It got worse and worse because as it arc'd there wasn't much metal left in the harness or the block. The damage was done.

I only mention this because that was a engine swap from a blown powerhead to a new long block. We swapped all the electrics over and then it started running poorly. We checked everything, and while we were prepping to swap a new block we found the spot where the shorting/arcing was happening.

I remember a long thread where CDan referenced a lot of older threads with this same code: CODE #83 #84 #85 93FZJ80 issue help

Which I am sure you've looked at that, already.

When you swapped in the new engine, did you use your original electrics or the donor's?

 

[Proven]

This also came up when I searched those codes on the googlenet: Land Cruiser 4.5L (1993 – 1994) – TroubleCodes.net

I never knew there was a "Normal Mode", is that a thing?

 

[Whiskerz]

Compression is good ? Timing is good ? Lets not forget the basics. Fuel pressure and volume ? Valves in adjustment ?

 

[ZackR]

When you did the wiring harness by the EGR did you remove all of the old heat wrap and expose the wires? On mine the heat wrap looked ok from the outside but once I cut it off I found a few wires that were shorted together due to burned insulation.

 

[rolliges]

^^^ Sounds like engine harness short.

 

[MoJ]

On a previously owned 94 I had a rough idle with stalling issues. It would run with throttle, albeit with less power, perhaps 80%. I replaced the typical parts. With a mechanic’s stethoscope it sounded like each injector was clicking. I finally gave up and took it to the dealer. The problem was the #5 injector.

 

[bigredmachine]

test your o2 sensors, you can do that from the obd port. I had bad sensors and a really crappy wire repair job by the po that was the cause of a similar misfire on mine.

 

[BILT4ME]

AFM / MAF / WHATEVERTHEHELLITSCALLED.....

Did you remove the two screws and yank on the wires?

Have you checked operation with the FSM on that thing listed above?

 

[SpeedAgent]

Thanks guys. It sounds like I need to reinspect the main wire harness. I have not checked actual fuel pressure, so I can't say for sure. Once it's warmed up it runs better, but not perfect.

Tonight, i started it when it was cool and it fired right up, but would barely get away from a stop without literally flooring it. Once floored the cruiser just takes off and accelerates great, but it was actually dangerously bogging on the road.

The wiring harness is original to my car. I have very little detail on the engine other than it is from a 97', had 160k on the clock when I got it, and compression was good. I was forced to do the HG about a month after it was put in, and it ran fine for about another month after that, but then I started having these issues.

 

[SpeedAgent]

AFM / MAF / WHATEVERTHEHELLITSCALLED.....

Did you remove the two screws and yank on the wires?

Have you checked operation with the FSM on that thing listed above?

Which screws? On the AMF?

 

[SpeedAgent]

test your o2 sensors, you can do that from the obd port. I had bad sensors and a really crappy wire repair job by the po that was the cause of a similar misfire on mine.

View attachment 2077155

I meant to list that in the original post; those are new.

 

[SpeedAgent]

When you did the wiring harness by the EGR did you remove all of the old heat wrap and expose the wires? On mine the heat wrap looked ok from the outside but once I cut it off I found a few wires that were shorted together due to burned insulation.

No, but I will reinspect.

 

[SpeedAgent]

Compression is good ? Timing is good ? Lets not forget the basics. Fuel pressure and volume ? Valves in adjustment ?

I really can't answer these yet. I've not messed with the valves, but I do know the guy who installed it said he had to dial back the timing from 9 degrees to 3 because he said it wasn't running well. Compression was good when engine was installed. The biggest disparity from any of the cylinders was 2% and they were all within spec.

 

[BILT4ME]

Which screws? On the AMF?

Yes. It is known that is people remove the screws and tug on the wires, it kills it. Varying issues.

 

[SpeedAgent]

Most of my experience working on engines isn't on Toyota. So forgive me if I am wrong.

You've done most of the fuel system and ignition system. The problem persists.

Since you've got a used engine in there, could be a wire pinched anywhere in the harness. It could be shorting. I had this happen with another type of engine (v8 outboard motor) where we pinched a harness and it was arcing against the engine block. It got worse and worse because as it arc'd there wasn't much metal left in the harness or the block. The damage was done.

I only mention this because that was a engine swap from a blown powerhead to a new long block. We swapped all the electrics over and then it started running poorly. We checked everything, and while we were prepping to swap a new block we found the spot where the shorting/arcing was happening.

I remember a long thread where CDan referenced a lot of older threads with this same code: CODE #83 #84 #85 93FZJ80 issue help

Which I am sure you've looked at that, already.

When you swapped in the new engine, did you use your original electrics or the donor's?

Original