This has been a pretty tough year for my 1992 3-FE FJ80. Outlined on other threads, the engine has basically been given a complete refresh, new HG, pretty much new ignition system, ect ect. I am not going to bog down the list of parts replaced upfront on this to hopefully reduce the red herrings. I have be chasing gremlins left over after pulling the engine apart for a few months now. I am leaving in 7 days to take a trip to Moab with my family and my stress level with this new issue is really worrying me. This is likely an electrical/sensor issue due to its intermittent behavior.
I live in SLC (4700' above sea level), and we have some pretty serious hills here. On level interstate the truck behaves great, and has zero problems holding 70-75 mph. Silky smooth, all systems normal. Truck gets pretty much 10 mpgs on the nose, which has been that way since I owned it. My issue is under certain instances when going up hill I will completely lose power. Most of the long steep grades around here require to push 3-3500 RPMs for several minutes, which the engine never had an issue with before the rebuild and for the first couple months after. Now, usually when the air is a little warmer (65F+) it will feel like it is slipping and losing power whenever I put the hammer down. It is a very weird feeling, the RPMs don't really drop off like its missing, I am usually at speeds well above 50, which would mean the Torque Converter is locked up and not slipping, but also does it at lower speeds. It is not related to a specific gear (has happened in what should be 2nd and 3rd). It just feels like all the power just vanishes. It happened one time which the engine ran warm (3/4) gauge afterward for the following 10 mins. After sitting for a couple hours, I drove back over the same hill and it rocketed up it with no issues at all and was nice and cool.
I have read some related 3-FE problems, which were:
Dirty/Clogged fuel pump screen (fuel filter is newer)
Throttle Position Sensor adjustment.
I plan to check out the screen tonight. I will test the TPS per the FSM tomorrow. I ordered 2 cans of B&G 44K so see if that will help clean out the system a little. I just want to make sure there is nothing else that might need to be checked since I have such a short time to knock this out. Or if anyone has some tests or ideas to isolate if this is a fuel, ignition, or mechanical (trans/tcase/torque converter) issue. I am not sure if I had an injector that was malfunctioning what that would feel like. I appreciate any leads or things to investigate outside the two listed above.
I live in SLC (4700' above sea level), and we have some pretty serious hills here. On level interstate the truck behaves great, and has zero problems holding 70-75 mph. Silky smooth, all systems normal. Truck gets pretty much 10 mpgs on the nose, which has been that way since I owned it. My issue is under certain instances when going up hill I will completely lose power. Most of the long steep grades around here require to push 3-3500 RPMs for several minutes, which the engine never had an issue with before the rebuild and for the first couple months after. Now, usually when the air is a little warmer (65F+) it will feel like it is slipping and losing power whenever I put the hammer down. It is a very weird feeling, the RPMs don't really drop off like its missing, I am usually at speeds well above 50, which would mean the Torque Converter is locked up and not slipping, but also does it at lower speeds. It is not related to a specific gear (has happened in what should be 2nd and 3rd). It just feels like all the power just vanishes. It happened one time which the engine ran warm (3/4) gauge afterward for the following 10 mins. After sitting for a couple hours, I drove back over the same hill and it rocketed up it with no issues at all and was nice and cool.
I have read some related 3-FE problems, which were:
Dirty/Clogged fuel pump screen (fuel filter is newer)
Throttle Position Sensor adjustment.
I plan to check out the screen tonight. I will test the TPS per the FSM tomorrow. I ordered 2 cans of B&G 44K so see if that will help clean out the system a little. I just want to make sure there is nothing else that might need to be checked since I have such a short time to knock this out. Or if anyone has some tests or ideas to isolate if this is a fuel, ignition, or mechanical (trans/tcase/torque converter) issue. I am not sure if I had an injector that was malfunctioning what that would feel like. I appreciate any leads or things to investigate outside the two listed above.