- Thread starter
- #21
New PCV valve and grommet. I'll check the brake booster when I get the throttle body back on.
Thanks, great suggestions!
FJ62 engine issues (3 Viewers)
- Thread starter BriSco
- Start date
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Thanks, great suggestions!
EscapeWagon62
SILVER Star
Long shot but did someone do a valve job on it recently?
I had mine done by a tech and they way over righted them, caused major fall on face symptoms.
I do them myself now.
I had mine done by a tech and they way over righted them, caused major fall on face symptoms.
I do them myself now.
- Thread starter
- #23
Not that he is aware of. As I said, he bought it this way hoping for an easy fix. I guess we could check the valve lash while waiting on the TB gasket.
I have 91 80 series but I think the 62s have the 3fe also so they should be similar. Anyway check all grounds and clean and tighten them back after coating the surfaces with die electric grease. Have you checked the screen in the tank on the fuel pump pickup? I ask because you say your son drained the tank. There still could be a lot of crap in there because my 80 has baffles and a pickup chamber. Fuel injectors also could be clogged. I am assuming it is running way lean but I have also seen them go into limp mode as someone else wrote which actually is full rich. Check the exhaust while its running and make sure it isn't putting out black smoke. Again vacuum leaks could be anywhere if it hasn't been desmogged. Intake boots can be cracked causing vacuum leaks. Wires, plugs, rotor, cap. Dont mess with the MAP. It is almost never that unless you mess with it then it will like trigger a check engine light. That's all I got for now.
I read through the posts and some of this has been mentioned but I thought I'd try and write a comprehensive post:
Where I start when I am dealing with a new vehicle to me or friends that is having issues:
Start with the basics and establish you have a sound foundation:
1. Tune up:
a. change the oil and filter
b. replace air and fuel filters
c. replace plugs, cap, rotor, wires
2. Battery and cables
a. Inspect your battery and make sure its clean and the terminals are clean. Make sure there isn't crusted acid all over the place, have a shop test the battery if needed
b. Inspect your battery terminals and replace if needed. Look at the connecting wires and make sure they are not frayed, green, corroded etc.
c. Inspect the fusible link and replace if it looks cooked.
d. with truck running measure voltage across battery and make sure its 12.6 to 14.4 volts. Try turning on the headlights and all electric accessories and measure the voltage. Make sure the voltage is holding at 13v or higher
e. inspect all of your grounds both on the battery, to the chassis, to the engine etc
3. Check the base timing is set around 7 deg
4. do a compression check
5. measure engine vacuum and check your idle speed
6. look for obvious vacuum leaks like broken vac lines. listen for leak noises
Once you have established that the core systems are intact and in spec then its time to start looking at the EFI components. These include:
a. Throttle position sensor (TPS)
b. O2 sensor
c. Airflow sensor
d. Temp sensor
e. ignition signal
f. Fuel Pressure Regulator (FPR)
Where I start when I am dealing with a new vehicle to me or friends that is having issues:
Start with the basics and establish you have a sound foundation:
1. Tune up:
a. change the oil and filter
b. replace air and fuel filters
c. replace plugs, cap, rotor, wires
2. Battery and cables
a. Inspect your battery and make sure its clean and the terminals are clean. Make sure there isn't crusted acid all over the place, have a shop test the battery if needed
b. Inspect your battery terminals and replace if needed. Look at the connecting wires and make sure they are not frayed, green, corroded etc.
c. Inspect the fusible link and replace if it looks cooked.
d. with truck running measure voltage across battery and make sure its 12.6 to 14.4 volts. Try turning on the headlights and all electric accessories and measure the voltage. Make sure the voltage is holding at 13v or higher
e. inspect all of your grounds both on the battery, to the chassis, to the engine etc
3. Check the base timing is set around 7 deg
4. do a compression check
5. measure engine vacuum and check your idle speed
6. look for obvious vacuum leaks like broken vac lines. listen for leak noises
Once you have established that the core systems are intact and in spec then its time to start looking at the EFI components. These include:
a. Throttle position sensor (TPS)
b. O2 sensor
c. Airflow sensor
d. Temp sensor
e. ignition signal
f. Fuel Pressure Regulator (FPR)
good idle and no power off idle = TPS bad or not adjusted correctly.
- Thread starter
- #28
Thanks! We did TPS checks yesterday. Failed one check miserably. Had to order from O’Reilly, should be in tomorrow. Of course his uses the one that no one has in stock, built 5/89 it takes the later style.
You can never find a bargain when you need one. I have accumulated spares of:
AFM
IACV
TPS
ECU
Circuit opening relay
EFI Relay
Distributor
I carry a spare CO relay and EFI relay in the truck. I had to pay for the TPS when it went bad because I thought I had a spare. I did have a couple spares but they were for the 22RE.
You can find deals and stash a spare instead of getting charged full price in a pinch.
AFM
IACV
TPS
ECU
Circuit opening relay
EFI Relay
Distributor
I carry a spare CO relay and EFI relay in the truck. I had to pay for the TPS when it went bad because I thought I had a spare. I did have a couple spares but they were for the 22RE.
You can find deals and stash a spare instead of getting charged full price in a pinch.
- Thread starter
- #30
Frustrating to me finding nothing in stock in Alaska. In Kansas City I never have an issue finding things...
TPS should be in today. I received the TB gasket yesterday, cleaned everything up for install. Cleaned all grounds and check continuity from engine to frame, frame to body, engine to body. All good. Checked routing of all vacuum hoses per chart on firewall. Did a thorough check of intake hose for cracks. Dis connected battery for a while. We'll see what happens when we get the TP sensor installed and adjusted.
I've watched several videos in the meantime and it runs exactly like ones in limp mode videos.
TPS should be in today. I received the TB gasket yesterday, cleaned everything up for install. Cleaned all grounds and check continuity from engine to frame, frame to body, engine to body. All good. Checked routing of all vacuum hoses per chart on firewall. Did a thorough check of intake hose for cracks. Dis connected battery for a while. We'll see what happens when we get the TP sensor installed and adjusted.
I've watched several videos in the meantime and it runs exactly like ones in limp mode videos.
- Thread starter
- #31
Ok no joy today.
Replaced TPS, adjusted per spec. passed all tests.
Over the last few days list of what we've completed:
Tested Fuel flow. Good
Cleaned engine grounds
Brake booster good
MAF/VAF passed all tests in FSM
EGR closed @ idle/ not stuck
Cap, rotor, wires new
No vacuum leaks found
Intake boot not cracked
Cleaned TB/new gasket
Cleaned connectors on VAF/TPS
Disconnected battery while installing throttle body.
Water temp sensors would be next steps.
If anyone wants to see what it is running like check this video at 1:15 showing limp mode. It is exactly what this one is doing.
Replaced TPS, adjusted per spec. passed all tests.
Over the last few days list of what we've completed:
Tested Fuel flow. Good
Cleaned engine grounds
Brake booster good
MAF/VAF passed all tests in FSM
EGR closed @ idle/ not stuck
Cap, rotor, wires new
No vacuum leaks found
Intake boot not cracked
Cleaned TB/new gasket
Cleaned connectors on VAF/TPS
Disconnected battery while installing throttle body.
Water temp sensors would be next steps.
If anyone wants to see what it is running like check this video at 1:15 showing limp mode. It is exactly what this one is doing.
The 3FE ECU is not sophisticated enough to have a limp mode. It is just reacting to it's inputs. Sounds to me like a clogged fuel supply, there is a bit of OE on that for the FJ62.
Replace your O2 sensors if you have not already. Even if you dont have codes. Night and day difference in the drive/acceleration in 62 I had with this same issue of falling flat on its face....
Down side is that sometimes replacing the O2 sensors is a bigger can of worms if they are stuck in place or the exhaust needs more work...
do it
Down side is that sometimes replacing the O2 sensors is a bigger can of worms if they are stuck in place or the exhaust needs more work...
do it
The 3fe does in fact have a limp mode triggered by a WOT for too long. Hold it wide open , it takes about 20 seconds. You need to reset the ECU after its triggered or it won't rev past about 1500 rpm. Not exactly sure as I do not have a tachometer. I have never been able to find any relevant reading material on this condition, I know from experience only.
I had very similar issues once upon a time. After changing my vacuum lines, cap and rotor, wires, spark plugs, fuel filter, o2 sensors, and filter it was my TPS. But I’m still glad I did everything else regardless. Good luck! Looks like you’re in your way to having everything new under the hood hah
Not exactly a limp mode but good to know.
What would you call it then if it isn't a limp mode ? After it is triggered , the engine will not rev until you reset the ecu. I'm fairly certain it is a protection protocol built into the computer. I will say that when I was having issues with triggering this mode , My exhaust was very quiet as I built it initially for a hunting trip with a very large muffler. It was difficult to hear the rev limiter. I redid the exhaust with a louder muffler and have only had it happen a few times since as I am more aware, generally when I'm racing it and too excited to get off the gas.
Sorry to take this thread off topic.
Ok, you are right
