om3gadagg3r
NAXJA Forum User
- Location
- Upper Michigan
Let me start by saying this is my first post so bear with me if its in the wrong place or full of newbness.
Ok, My 89 Xj had a tired 4.0, and one day she started knocking and it as progressively getting louder so I ordered a 4.7L stroker and swapped it in.
I had my renix TB bored to 60mm and upgraded to 24lb Ford injectors. These were the only changes i made. I replaced all hoses, wires, cap, rotor, thermostat, water pump, and spark plugs. I hooked everything up the way it was, with the exception of the vapor canister. I replaced the fuel filter and added a K&N air element. I had to make a spacer for the nose of the crank as the new stroker crankshaft was longer in this area. Everything went back together nicely and to my liking. I used Valvoline VR1 for the zinc properties and added a bottle of Lucas zinc additave for the cam. Upon startup she ran very rough and erratic, surging up and down but it smoothed out enough to hold at 2800 for 20mins as reccomended by the builder. In this 20 mins my cat began to glow orange melting my carpet in the rear floor area. Not knowing if the cat was plugged up I cut out the cat and replaced it with pipe. The rest of the exhaust is stock and in good shape. After this break in run I double checked timing and all vaccum hoses and could find nothing wrong. I took voltage readings at TPS and o2 sensors and they seem to be within specs that I have. Map is hooked up and working as well. The engine starts and idles decent but as soon as throttle is given it begins to run rough and pop. I checked the knock sensor and while installing the engine I broke the housing on the sensor, so I replaced that also thinking perhaps that wasnt letting the ecm advance timing. But this was no help. I have read and was told that the renix computer would be able to accomodate my larger TB and injectors but it seems like its either not getting the fuel or the timing isnt being controlled correctly.
Ive read up on adjustable Maps and other things but from the sound of those modifications I have something more drastic going on. I was thinking about grinding the dist. to allow adjustment but want to get some input here first. Please feel free to offer advise or ask for more information. I love my xj and am determined to see this beast purr
Sorry for the long post but Im trying to be complete.
Thanks,
Ω
Ok, My 89 Xj had a tired 4.0, and one day she started knocking and it as progressively getting louder so I ordered a 4.7L stroker and swapped it in.
I had my renix TB bored to 60mm and upgraded to 24lb Ford injectors. These were the only changes i made. I replaced all hoses, wires, cap, rotor, thermostat, water pump, and spark plugs. I hooked everything up the way it was, with the exception of the vapor canister. I replaced the fuel filter and added a K&N air element. I had to make a spacer for the nose of the crank as the new stroker crankshaft was longer in this area. Everything went back together nicely and to my liking. I used Valvoline VR1 for the zinc properties and added a bottle of Lucas zinc additave for the cam. Upon startup she ran very rough and erratic, surging up and down but it smoothed out enough to hold at 2800 for 20mins as reccomended by the builder. In this 20 mins my cat began to glow orange melting my carpet in the rear floor area. Not knowing if the cat was plugged up I cut out the cat and replaced it with pipe. The rest of the exhaust is stock and in good shape. After this break in run I double checked timing and all vaccum hoses and could find nothing wrong. I took voltage readings at TPS and o2 sensors and they seem to be within specs that I have. Map is hooked up and working as well. The engine starts and idles decent but as soon as throttle is given it begins to run rough and pop. I checked the knock sensor and while installing the engine I broke the housing on the sensor, so I replaced that also thinking perhaps that wasnt letting the ecm advance timing. But this was no help. I have read and was told that the renix computer would be able to accomodate my larger TB and injectors but it seems like its either not getting the fuel or the timing isnt being controlled correctly.
Ive read up on adjustable Maps and other things but from the sound of those modifications I have something more drastic going on. I was thinking about grinding the dist. to allow adjustment but want to get some input here first. Please feel free to offer advise or ask for more information. I love my xj and am determined to see this beast purr
Sorry for the long post but Im trying to be complete.
Thanks,
Ω