FJ62 engine issues (1 Viewer)

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BriSco

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My first post here. I'm impressed with this site.
My son has an 89 FJ62 that runs like crap and I'm hoping to get some ideas here. It has not ran right since he purchased it.
I just came to visit him in Anchorage and to assist getting this thing to run right, so I have limited time.

It seems to start OK, seems to idle OK. It has no acceleration or power. It seems to fall on its face. Sitting in park it seems any low vaccum situation the engine surges back and forth like it is starving for fuel. Driving it I notice that the engine will not accelerate under load, but starts popping and bucking. I did notice that accelerating downhill and dropping in into 2nd raising the rpm, it smooths out and has power in the higher rpm.

So far he has had a shop check compression, fuel pressure, the catalytic converters, plugs and wires, and for vacuum leaks. The shop recommended changing fuel injectors. Since it runs at high rpm, I think they're fine. You just cannot accelerate the engine quickly under load or no load.

I'm leaning towards MAF or engine timing under low vacuum conditions.

Thanks for any and all suggestions!!!
 
Last edited:
I don't have them handy. The shop did check and declared compression on all cylinders was good. I see that I forgot to mention that in my post

Brian
 
I've been doing some reading and it seems like the TPS adjustment is somewhat critical on these as well. What are the symptoms of out of adjustment?
 
High idle is a common symptom. You can check the TPS resistance numbers per the FSM. If you remove it, you may also notice some physical symptoms such as slow/week spring return. I replaced mine 2 months ago.
 
Also check the screw on the fuel pulsation damper. Mine was backed out all the way.

forum.ih8mud.com

What the deuce is this thing?

I think I mentioned this years ago, but for the record the screw is for calibration, not for tightening down all the way. Here's Toyota's statement on it: The screw mounted at the top of the damper provides an easy check for fuel system pressure. When the screw is up it means the fuel rail is...
forum.ih8mud.com forum.ih8mud.com
 
Maybe too obvious a suggestion... but did you try a new fuel filter???
 
kbfj621989 said:
Also check the screw on the fuel pulsation damper. Mine was backed out all the way.

forum.ih8mud.com

What the deuce is this thing?

I think I mentioned this years ago, but for the record the screw is for calibration, not for tightening down all the way. Here's Toyota's statement on it: The screw mounted at the top of the damper provides an easy check for fuel system pressure. When the screw is up it means the fuel rail is...
forum.ih8mud.com forum.ih8mud.com
Click to expand...

Thanks!!
I'll have to take look at that one.
 
Has it been baselined? Cap/rotor/plugs/wires/filters. I'd desmog it anyway, you're going to want that and it might help with this specific problem anyway.

I'd stethoscope the injectors and see if they all sound similar. I have had them drop offline and come online at higher RPM before, but that usually doesn't give you like an idle surge or anything.

TPS is an easy check and critical like you said.
MAF may be able to be ohmed out and test? I can't say for sure.

I know you said it has been tested, but it really sounds a lot like a vacuum leak
 
Sounds like a vacuum leak to me. Carefully check the large intake hose from the air Cleaner to the Throttle Body.
That corrugated section can hide a split in that piping. I'd carefully remove it and inspect it thoroughly.
:beer:
 
Thanks everyone for the suggestions. The weather should allow some work on it today. My son lives offbase in an apartment so we are limited a bit where we can work on it.

To answer a some of the questions and give a bit more information, he bought it running this way as he purchased it cheap figuring it shouldn't take much to fix. The guy he bought it from has multiple Cruisers and hadn't got this one right yet. He had replaced the distributor along with wires/cap/rotor/plugs. His opinion was injectors. (He is still assisting). Oh 200k on the miles, NO rust and a really clean interior.
So far my son has drained the fuel tank and replaced fuel. New plugs/rotor/cap/wires. Oil and filter change. It has a new looking K&N air filter (oil on MAF?).
He took it to a place in Eagle River that specializes in Land Cruisers where he checked the cats, fuel pressure and compression and for vacuum leaks. He declared it all good and suggested water in the gas and/or new injectors. He has since purchased new injectors but we have not had a chance to replace them yet.
He did drain the tank and got a bout a pint (!) of water out of it. Added fresh fuel and replaced the fuel filter.

This thing will not climb a hill on the street and will barely pull itself away from a stoplight, sputtering and bucking. It does idle perfectly.
Another possible clue, sitting at an idle if you crack the throttle open it the rpm will surge up and down with perfect timing between cutting out and running as the engine tries to accelerate.
 
BriSco said:
The guy he bought it from has multiple Cruisers and hadn't got this one right yet. He had replaced the distributor along with wires/cap/rotor/plugs.
Click to expand...

Check the timing to make sure that the distributor is not off a tooth.
 
BriSco said:
This thing will not climb a hill on the street and will barely pull itself away from a stoplight, sputtering and bucking. It does idle perfectly.
Another possible clue, sitting at an idle if you crack the throttle open it the rpm will surge up and down with perfect timing between cutting out and running as the engine tries to accelerate.
Click to expand...
That sounds to me like it is in Limp mode. That used to happen to me in my rock crawler when I was climbing or trying to climb and applied WOT for too long of a period. Have you disconnected the battery yet ? That would re-set the ECU and return it to normal in my case.
 
OK, an update on what we have done so far.
Plugs good and gapped correctly. Inspected wires, rotor and cap. All good.
Inspected VAF, all values per service manual. Disconnected battery overnite and reconnected it. No change.
Checked hoses from air cleaner to throttle body. Good.
Removed throttle body and cleaned, waiting on gasket and feeler gauge to check resistance on it.
Fuel pressure is good.
Compression on all cylinders is good.
Cats are clear.
No vacuum leaks found at idle. I've sprayed carb cleaner around and on all hoses and connections.
Idles about 625 rpm.


It idles in park just fine with a random miss once in a while.
Putting it in drive with foot on brake it starts to run roughly and misses more frequently.
As load increases it runs even more roughly.
Try to drive away and it falls on it's face bucking and spitting.

I will say that once you get it up to 30-40 mph or so and manually downshift to keep rpms up, it runs smoothly and accelerated well. Until it shifts and is put under load with open throtttle, it falls on it's face again.
It's 0-40 time is about 60 - 70 seconds.

@Advent Cruisers Only is where I believe he took it. He didn't know what was wrong with it and suggested injectors. My son had purchased a set of rebuilt injectors from RockAuto. I don't think we will get them installed before I leave due to having no place to do them. (Apartment living)
 
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