ok here is the deal...
88 XJ 4.0 auto trans, swapped in 96 4.0, 95 standard trans. Items used on 96 motor in my reply below.
Map sensor removed from 96 throttle body and vacuum hose routed from there to 88 MAP on firewall. TPS input = 4.66 output adjusted to .77 left auto 4 way plug unplugged. NSS jumpered at connectors under hood near dipstick tube.
Here is the problem.......Rough idle when cold. When warm it will idle fine for 30-60 seconds dip down 200-300 rpms and then climb back up and idle fine again for another 30-60 seconds and so on. Other than this problem it runs fine and have no other problems so far. The swap as fairly simple except for the belt routing. TPS adapting was done with a roll pin and 2 brass flare nuts. Pretty good on gas, but a stong exhaust smell sometimes. Any input would be helpful.
88 XJ 4.0 auto trans, swapped in 96 4.0, 95 standard trans. Items used on 96 motor in my reply below.
Map sensor removed from 96 throttle body and vacuum hose routed from there to 88 MAP on firewall. TPS input = 4.66 output adjusted to .77 left auto 4 way plug unplugged. NSS jumpered at connectors under hood near dipstick tube.
Here is the problem.......Rough idle when cold. When warm it will idle fine for 30-60 seconds dip down 200-300 rpms and then climb back up and idle fine again for another 30-60 seconds and so on. Other than this problem it runs fine and have no other problems so far. The swap as fairly simple except for the belt routing. TPS adapting was done with a roll pin and 2 brass flare nuts. Pretty good on gas, but a stong exhaust smell sometimes. Any input would be helpful.
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