LJ-78 Fuel Pump Needed. Advice also NEEDED!

[masface]

Hey everybody,

My '91 LJ78 Prado has a large issue and I need some advice. She starts and idles perfectly, no smoke or anything. It also will idle up if you give it throttle but it takes longer than normal. But it gets really weird if you try to take it for a drive. It has no power. And I dont mean the normal "I drive a Prado and im always late" kind of no power, like ZERO POWER. It takes about 500 Meters to get up to 50. I had the fuel pump governer cover off to replace the seal. In doing so I had to remove the RPM sensor completley( it was seized to the cover). Is it possible that in removing this pick-up I somehow messed up the timing of the fuel pump? I have had a JDM mechanic rebuild the pump and found no crud or anything out of place. A few members on here have helped me a lot with this issue and brought up the idea of me possibly messing up the fuel pump timing. If this is the case Im fairly certain I may need a new fuel pump.

So it comes to this, any body know where to pick up a fuel pump for my rig? I know its not going to be cheap but Ive tried a number of other possibilities and this is the only thing that comes to mind. And its the only thing I took apart before the issues started.

Please guys lets get my beautiful girl back on the road!

Thanks!!

 

[roscoFJ73]

A few members on here have helped me a lot with this issue and brought up the idea of me possibly messing up the fuel pump timing. If this is the case Im fairly certain I may need a new fuel pump

You haven't mentioned where you are. But before you splash out on a new pump, it would be highly unlikely you need a new pump because of you messing with the fuel pump timing.
With all the good intentions of your JDM mechanic, its unlikely he has the equipment to bench test an injection pump and do the necessary adjustments.
So you need a diesel fuel injection specialist.

Is it possible that in removing this pick-up I somehow messed up the timing of the fuel pump?

Yes, I think that is highly likely. Take a note of the numbers on the pump and start looking for an RPM sensor. When people know where you are ,they can steer you in the right direction.

 

[Nas90tdi]

From my experience, a diesel engine that starts and idles generally does not have a timing issue that keeps it from driving correctly to that degree. If it's starting and idling well, timing is close-ish. And, the same with needing a new IP. They will often run leaking fuel and all sorts of other bad stuff. They tend to be an all or nothing type device. I drove a Bosch pump for months leaking fuel right out of the throttle plate shaft until I could get around to pulling it off and replacing the o-ring. So, as Roscoe said, probably not in need of a new pump.
I would start looking at simpler things first. Clogged fuel filter, algae in the tank, boost leaks, boost feed to sensor loose or cracked. Or the simplest of them all,the boost sensor hose popped off right at the manifold. If that engine is running as basically normally aspirated the level of slow is unreal.
Good luck, and I bet someone with more time spent working on that pump will chime in shortly and give you even more info.

 

[GTSSportCoupe]

Definitely check the stuff that Nas90tdi suggested, those are good ideas. He made some good points about the starting and idling.

Is your check engine light on? Have you pulled the ECU error codes?

If it turns out that sensor is the issue, you *might* be able to correct the timing enough by changing the value of the timing correction resistor on the side of the injection pump. You can access the wires at the ECU in the glove compartment. I could tell you the wiring colors and send you a potentiometer. Your timing might be out too much for this to help though.

I know that Rocky Mountain Imports in Victoria does stock spare injection pumps, but I bet it won't be cheap. He bought my old one a while back.

You could inquire into this truck. Just buy the whole thing and get it shipped to your place. Spare parts for a long time! Toyota Prado 1991 Swap the injection pump to your engine.

I did re-seal my injection pump a few years ago. Resealed my rotary injection pump Here is one of the pictures showing the NE sensor. So you removed the two screws holding it in place?

 

[GTSSportCoupe]

Also, the only time my engine ever ran the way you're describing yours, is when I ran out of fuel. Gauge showed 1/8, but I was totally out. Basically, the injection pump was not getting fuel. The more I think about it, the more this seems to match your symptom.

 

[Nas90tdi]

Fuel issues seems the most likely to me as well. While I agree the timing can/will cause issues. Him saying it cranks and idles good makes me suspect fueling. The timing can definitely have an impact on power, but it also often presents as hard starting, excessive diesel clatter, smoke.
He didn't mention any of that, just the loss of power when driving.
Masface, are you seeing any other indicators beside it being low on power?

 

[GTSSportCoupe]

Fuel issues seems the most likely to me as well. While I agree the timing can/will cause issues. Him saying it cranks and idles good makes me suspect fueling. The timing can definitely have an impact on power, but it also often presents as hard starting, excessive diesel clatter, smoke.
He didn't mention any of that, just the loss of power when driving.
Masface, are you seeing any other indicators beside it being low on power?

The more I think about it, I totally agree. I did have my timing belt out one tooth after I did my injection pump re-seal (despite having double checked). When I fired it up the timing was really advanced. It clattered and smoked like mad. Also, because the injection pump timing sensor was out compared to the crank sensor, the computer threw an ECU error code and turned on the check engine light. So if this is not happening for masface, then the issue might lie else where.

@masface When you did the work on your injection pump, what else did you have to remove or disconnect to do the job? Maybe the problem is related to that somehow.

 

[GTSSportCoupe]

@masface Maybe take a bunch of pictures of the injection pump side of the engine, and down around the injection pump. Maybe we can spot what the problem is....?

 

[masface]

The more I think about it, I totally agree. I did have my timing belt out one tooth after I did my injection pump re-seal (despite having double checked). When I fired it up the timing was really advanced. It clattered and smoked like mad. Also, because the injection pump timing sensor was out compared to the crank sensor, the computer threw an ECU error code and turned on the check engine light. So if this is not happening for masface, then the issue might lie else where.

@masface When you did the work on your injection pump, what else did you have to remove or disconnect to do the job? Maybe the problem is related to that somehow.

Hey guys thanks for the help. I live in Penticton, British Colombia Canada. The cruiser is about 2 hours away living at the mechanics shop. So I will get him to take some photos. As for the work I did @GTSSportCoupe yes I did remove those two star head bolts that hold the pick-up to the governer body. This is where I'm thinking the fuel pump timing was affected as this is the only part other than the cover that I removed.

I have tried replacing the turbo pressure sensor(intake manifold pressure sensor) and replaced the hoses between it and the throttle body so no issues there.(I wish) The strangest thing to me is that it will NOT smoke. If the timing we're out,as a few of you said, it would smoke and rattle even at idle correct? This is not the case, it runs and starts smoothly. Although the Reva are slow to build. Not really sluggish but definitely slower than normal. I had the ECU replaced when the mechanic found melted resistors in the hopes that maybe our problem lay there but sadly there was no change with the new ECU (numbers matched and everything). I'll get back to you all with a couple photos soon. I like what I'm hearing about maybe not having to buy a $2200 injector pump!

 

[masface]

From my experience, a diesel engine that starts and idles generally does not have a timing issue that keeps it from driving correctly to that degree. If it's starting and idling well, timing is close-ish. And, the same with needing a new IP. They will often run leaking fuel and all sorts of other bad stuff. They tend to be an all or nothing type device. I drove a Bosch pump for months leaking fuel right out of the throttle plate shaft until I could get around to pulling it off and replacing the o-ring. So, as Roscoe said, probably not in need of a new pump.
I would start looking at simpler things first. Clogged fuel filter, algae in the tank, boost leaks, boost feed to sensor loose or cracked. Or the simplest of them all,the boost sensor hose popped off right at the manifold. If that engine is running as basically normally aspirated the level of slow is unreal.
Good luck, and I bet someone with more time spent working on that pump will chime in shortly and give you even more info.

Definitely check the stuff that Nas90tdi suggested, those are good ideas. He made some good points about the starting and idling.

Is your check engine light on? Have you pulled the ECU error codes?

If it turns out that sensor is the issue, you *might* be able to correct the timing enough by changing the value of the timing correction resistor on the side of the injection pump. You can access the wires at the ECU in the glove compartment. I could tell you the wiring colors and send you a potentiometer. Your timing might be out too much for this to help though.

I know that Rocky Mountain Imports in Victoria does stock spare injection pumps, but I bet it won't be cheap. He bought my old one a while back.

You could inquire into this truck. Just buy the whole thing and get it shipped to your place. Spare parts for a long time! Toyota Prado 1991 Swap the injection pump to your engine.

I did re-seal my injection pump a few years ago. Resealed my rotary injection pump Here is one of the pictures showing the NE sensor. So you removed the two screws holding it in place?

From my experience, a diesel engine that starts and idles generally does not have a timing issue that keeps it from driving correctly to that degree. If it's starting and idling well, timing is close-ish. And, the same with needing a new IP. They will often run leaking fuel and all sorts of other bad stuff. They tend to be an all or nothing type device. I drove a Bosch pump for months leaking fuel right out of the throttle plate shaft until I could get around to pulling it off and replacing the o-ring. So, as Roscoe said, probably not in need of a new pump.
I would start looking at simpler things first. Clogged fuel filter, algae in the tank, boost leaks, boost feed to sensor loose or cracked. Or the simplest of them all,the boost sensor hose popped off right at the manifold. If that engine is running as basically normally aspirated the level of slow is unreal.
Good luck, and I bet someone with more time spent working on that pump will chime in shortly and give you even more info.

Thanks for your help. so for starters I totally agree that those pumps will run while leaking all over the place. Thats the reason i took the governer cover off in the first place. haha. Fuel filter is brand new, there are no boost leaks or turbo issues. Ive replaced all of the hoses between the turbo pressure sensor and throttle manifold. Algea in the tank is a good thought but would i have seen evidence of that when i changed the fuel filter? I just really dont know where else to look, I thought possibly it could be the torque converter but I dont think the symtoms match up.