I just got my 1993 land cruiser running again after doing the head gasket repair. In park and neutral, the idle is fine (~700-800 rpm when warm). When I shift into reverse or drive, the idle falls to ~400 and often time stalls out. It's almost like the ECM isn't recognizing or compensating for the extra load of being in drive/reverse. There is no check engine light once the engine is running.
I couldn't find anything in the FSM about this specific scenario so I started searching this forum also have not found an exact match to my issue. If I missed someone's thread on a similar issue, I'd love to read through that. There was some mention of the "PNP switch circuit" in the FSM troubleshooting table but I'm not familiar with what the PNP switch is (shifting switch?).
I do have some exhaust leaks in my downpipes and Cat's but dropping ~$1500-$2000 on downpipes and CA legal Cat's isn't in the budget right now.
Here is everything I replaced while doing the head
1. all ignition things (coil, wires, cap, rotor, plugs)
2. all fuel injectors
3. all vac lines
4. fuel filter
Some things I'm going to try (but please add other ideas)
1. IAC cleaning (I measured the resistance but will try cleaning it per a success in a different thread)
2. Double check ignition timing
3. Double check my compression test
4. Change trans fluid though it is fresh ~3k miles ago
5. Re-check VAF and TPS despite testing them a week ago for a different reason.
I couldn't find anything in the FSM about this specific scenario so I started searching this forum also have not found an exact match to my issue. If I missed someone's thread on a similar issue, I'd love to read through that. There was some mention of the "PNP switch circuit" in the FSM troubleshooting table but I'm not familiar with what the PNP switch is (shifting switch?).
I do have some exhaust leaks in my downpipes and Cat's but dropping ~$1500-$2000 on downpipes and CA legal Cat's isn't in the budget right now.
Here is everything I replaced while doing the head
1. all ignition things (coil, wires, cap, rotor, plugs)
2. all fuel injectors
3. all vac lines
4. fuel filter
Some things I'm going to try (but please add other ideas)
1. IAC cleaning (I measured the resistance but will try cleaning it per a success in a different thread)
2. Double check ignition timing
3. Double check my compression test
4. Change trans fluid though it is fresh ~3k miles ago
5. Re-check VAF and TPS despite testing them a week ago for a different reason.