I have a 95 yj 4.0 HO automatic. On cold mornings (40 degrees) It wont start unless your floor it and crank for quite some time. I have replace rotor bug, cap, plugs and wires,coil and fuel pump. fuel pressure in line registers in spec and does not loose pressure. MAP sensor and some other sensor has been replaced. Once we cranked we checked the plugs and thought they would be soked with fuel but found them dry. Once the vehicle starts and warms up it starts every time. leave till next morning and we start all over. We think the ECU is not sending a signal to send extra fuel to ack as a choke. anybody have any ideas or know of a good place to get a new ECU.
95 yj wont start in cold weather
- Thread starter osugrads
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Bounty__Hunter
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I would say to give the throttle body a good bench cleaning, paying special attention to the IAC housing and plunger that control the idle.
my mechanic has a ecu from a 92 and it fired right up, ran like crap due to security settings. put my ecu back in the next morning and nothing. put the other ecu in and again fired up. I found Americore in FL and they will rebuild mine and will have a lifetime warranty cost $349. No good without it.
doesn't the 4.0 have sequential fuel injection? i would check out the cold-start injector and the thermo-time switch circuit before i invested in a new ecu. i can't explain why swapping another ecu allowed it to start, but these systems can be tricky and the old junkyard method of changing parts till it's fixed can get real expensive real fast. good luck, john
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