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- June 3, 2003
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- Year, Model & Trim Level
- OBD-1 Kenobi
I'm going to throw my $.02 in here as I feel im qualified to answer (having done a 5.0 swap in a job 1 ST, a job 2 sport, and a 98 eddie bauer)
are you sure about this? pretty sure all v8's came with 3.73 ratio
as far as pats...the best option for any swap is the have the original keys to the vehicle programmed to the different pcm...trust me, it prevents a lot of headaches. second gen PATS explorers (98-01) use 4 components to PATS:
Key with RFID chip
Key transceiver (antenna)
Pats Module
PCM
the transceiver "sees" the key, sends the RFID number to the pats module over the SCP data network, then the pats module sends a yay/nay signal to the pcm telling it to either start (correct key) or disable the injectors (wrong key)... Tying the old key to the transceiver is a bad idea because
A) defeats the purpose of having PATS (to prevent theft)
B) could cause RFID interference between two pats keys, thus could cause no start P1260 codes and disabling the vehicle
If it's a job one ST, swap the 98 pcm over, and have the pats system reflashed to accept the ST keys (same style keys...easy way to tell is if the ST keys and the 98 keys look identical, you have job one. if the ST key is more oval shaped and does NOT look identical to 98 keys, you have job 2)
if you have Job 2 ST, you will need to swap over the pcm, and wire in the PATS module from the 98 to the ST (not hard to do, already done on my 2002 Sport 5.0). then get two new keys cut from your original ST keys in the style of the 98 and have them programmed. Job 2 keys are incompatible with 98-01 PATS
Now for the motor...obviously the engine and trans need swapped over, as well as the motor mounts, power steering cooler (and if Job 2 ST, the entire rack...reason is the power steering lines will not thread in and you will either need new lines custom made or swap over the rack), radiator and condenser, engine harness (more on electrical in a moment), exhaust from muffler forward. And since you have a 98 donor (which is a return type fuel system) you will need a returnless fuel rail from a 99-01 5.0 (probably from a junkyard). obviously all the front engine dress (water pump, brackets, ect). all the evap vacuum lines that are 5.0 specific. also the vacuum supply line that runs to the hvac control head will need swapped over as well as the accel cable and the cruise control module. you want to mimic everything in the engine bay of you ST to be that of your donor (except the fuel rail...easier to swap that then convert your fuel system to return style)
now wiring...you can actually use you SOHC engine BAY harness (the harness the wraps around the engine bay from the firewall) by moving some circuits around (im doing this from memory, so this is more a guide than instructions)
It's best to extend the bulkhead connector that sits on top of the engine 14 inches in order not to bind, as the 5.0 connector sits further to the passenger side on the firewall, as compared to the SOHC connector which is on the driver side of the engine
that's all I can think of at the moment, biggest thing is bite the bullet and have the pats system programmed properly so that way when everything is said and done, the truck runs, starts, and drives as designed, and even to a factory level. Ill close this with some inspiration:
The donor 98 has 3.55 Limited Slip with disc brakes rear end.
are you sure about this? pretty sure all v8's came with 3.73 ratio
as far as pats...the best option for any swap is the have the original keys to the vehicle programmed to the different pcm...trust me, it prevents a lot of headaches. second gen PATS explorers (98-01) use 4 components to PATS:
Key with RFID chip
Key transceiver (antenna)
Pats Module
PCM
the transceiver "sees" the key, sends the RFID number to the pats module over the SCP data network, then the pats module sends a yay/nay signal to the pcm telling it to either start (correct key) or disable the injectors (wrong key)... Tying the old key to the transceiver is a bad idea because
A) defeats the purpose of having PATS (to prevent theft)
B) could cause RFID interference between two pats keys, thus could cause no start P1260 codes and disabling the vehicle
If it's a job one ST, swap the 98 pcm over, and have the pats system reflashed to accept the ST keys (same style keys...easy way to tell is if the ST keys and the 98 keys look identical, you have job one. if the ST key is more oval shaped and does NOT look identical to 98 keys, you have job 2)
if you have Job 2 ST, you will need to swap over the pcm, and wire in the PATS module from the 98 to the ST (not hard to do, already done on my 2002 Sport 5.0). then get two new keys cut from your original ST keys in the style of the 98 and have them programmed. Job 2 keys are incompatible with 98-01 PATS
Now for the motor...obviously the engine and trans need swapped over, as well as the motor mounts, power steering cooler (and if Job 2 ST, the entire rack...reason is the power steering lines will not thread in and you will either need new lines custom made or swap over the rack), radiator and condenser, engine harness (more on electrical in a moment), exhaust from muffler forward. And since you have a 98 donor (which is a return type fuel system) you will need a returnless fuel rail from a 99-01 5.0 (probably from a junkyard). obviously all the front engine dress (water pump, brackets, ect). all the evap vacuum lines that are 5.0 specific. also the vacuum supply line that runs to the hvac control head will need swapped over as well as the accel cable and the cruise control module. you want to mimic everything in the engine bay of you ST to be that of your donor (except the fuel rail...easier to swap that then convert your fuel system to return style)
now wiring...you can actually use you SOHC engine BAY harness (the harness the wraps around the engine bay from the firewall) by moving some circuits around (im doing this from memory, so this is more a guide than instructions)
- Yellow/white wire charging circuit
- Dark Green/white oil pressure circuit
- a/c high side switch (in SOHC, part of engine harness, in 5.0, part of engine BAY harness
It's best to extend the bulkhead connector that sits on top of the engine 14 inches in order not to bind, as the 5.0 connector sits further to the passenger side on the firewall, as compared to the SOHC connector which is on the driver side of the engine
that's all I can think of at the moment, biggest thing is bite the bullet and have the pats system programmed properly so that way when everything is said and done, the truck runs, starts, and drives as designed, and even to a factory level. Ill close this with some inspiration: